New Yamaha patents

Raining like crazy today, so it’s a good chance to look for new patents and patent applications.

First, here are a few new technical patents assigned to Yamaha. US Patent 9,536,508 titled “Accompaniment data generating apparatus,” awarded on January 3, 2017, describes accompaniment generation using a combination of MIDI and audio waveforms. The accompaniment generator follows chord changes, etc. just like today’s arrangers except that it also plays back melodic (pitched) audio phrases as well as MIDI. This is very likely the nexus of the next generation of Yamaha arrangers (flagship “GENOS“).

US Patent 9,514,728 titled “Musical performance apparatus that emits musical performance tones and control tones for controlling an apparatus,” awarded December 6, 2016, describes a system for near ultrasonic communication between a tablet and a keyboard. Software on the tablet controls tone generation on the keyboard, allowing an app to play back a musical performance (e.g., MIDI over near ultra sonic sound). I suspect that some future Yamaha patent will use this technology for wireless tablet to keyboard communication in place of Bluetooth or WiFi.

The third patent, number 9,489,938 is titled “Sound synthesis method and sound synthesis apparatus” and was awarded on November 8, 2016. The patent abstract says it best:

A sound synthesis apparatus connected to a display device, includes a processor configured to: display a lyric on a screen of the display device; input a pitch based on an operation of a user, after the lyric has been displayed on the screen; and output a piece of waveform data representing a singing sound of the displayed lyric based on the inputted pitch.

Yamaha have a stellar technology base in VOCALOID. I believe they are working toward a real-time system to sing lyrics. This would be a real breakthrough especially for pitch-challenged vocalists like me!

Finally, Yamaha was awarded several design patents covering the external industrial design of synth and arranger keyboards:

    D772,974   PSR-S670   November 29, 2016
    D776,189   Montage    January 10, 2017
    D778,347   YPT-255    February 7, 2017
    D778,346   Reface YC  February 7, 2017
    D778,345   Reface CP  February 7, 2017
    D778,344   Reface DX  February 7, 2017
    D778,343   Reface CS  February 7, 2017
    D778,342   ????       February 7, 2017

The final design patent, D778,342, is perplexing. I haven’t been able to associate it with a product in the North American market. A future product perhaps? It shows a 26-key keyboard with a four way, cursor-like pad. The keyboard design is E-to-F! I/O is on the left side panel.

Tip-toe through the tech

Last year ’bout this time, we were all holding our collective breath awaiting the new Yamaha Montage. There are two products which I expect to see from Yamaha sometime in the next one to two years:

  1. The successor to the mid-range MOXF synthesizer, and
  2. The successor to the top-of-the-line (TOTL) Tyros arranger workstation.

NAMM 2017 seems a little too soon for both products. In the case of the MOXF successor, Yamaha conducted marketing interviews during the summer of 2015. I would guess that MOXF sales are still pretty good and no new products from the usual suspects (Korg, Roland) are visible on the horizon. The Krome and FA could both use an update themselves. Not much market pressure here at the moment. (Korg’s NAMM 2017 announcements are, so far, a little underwhelming.)

Read my MOX retrospective and interview follow-up.

I suspect that the Tyros successor is somewhat closer to launch. Speculation has been heated ever since Yamaha filed for a US trademark on the word mark “GENOS”. The word mark was published for opposition on November 15, 2016. “Published for opposition” means that anyone who believes that they will be damaged by registration of the mark must file for opposition within 30 days of publication. If “GENOS” is indeed the name for the Tyros successor, then the 30 day period ending December 15, 2016 is cutting it very close to NAMM 2017. Even more ludicruous if Yamaha were to begin manufacturing products printed with that name for a NAMM 2017 launch. Imagine the scrap if opposition was successful!

For quite some time, I have been meaning to summarize the key U.S. patents that I believe to be GENOS-related. (Assuming that “GENOS” is the name!) I’ve procrastinated because the launch date is most likely fall 2017 at the earliest as previous Yamaha mid- and high-end arranger models are typically launched in the fall in anticipation of the holiday selling season.

A much larger barrier is the task of reading and gisting the patents. Patents are written in legalese and are much more difficult to read than the worst written scientific papers! One of the folks on the PSR Tutorial forum suggested making a list of the top five technologies for the new TOTL arranger. I generally hate the superficial nature of “list-icles,” but the suggestion is a good one. Nothing will get done as long as the barrier is big because I would much rather jam and play! I’m supposed to be retired.

The 2016 Yamaha annual report states that Yamaha want to make innovative products which are not easily copied by competitors. Patents — legally protected intellectual property — are essential to achieving this goal. Generally, a company only applies for a patent on technology in which they have a serious business interest due to the significant cost of obtaining and maintaining patent protection.

So, here are a few of Yamaha patented technologies which could appear in future products — perhaps GENOS, perhaps others.

SWP70 tone generator

This may seems like old news…

The next generation SWP70 tone generator first appeared in the mid-range Yamaha PSR-S970 arranger workstation. The SWP70 made its second appearance in the Yamaha Montage synthesizer. The S970 incorporates only one SWP70 and does not make full use of the chip. (At least three major interfaces are left unconnected.) In keeping with Yamaha’s TOTL design practice, the Montage employs two SWP70 integrated circuits: one each for AWM2 sample-playback and FM. A second sample cache interface on the AWM2 side is unconnected.

The Tyros successor likely will use two SWP70 tone generators, too. The number of available tone generation channels with two SWP70s will be massive (512 channels). Yamaha could opt for a single SWP70 and still outmatch the current generation Tyros 5. Like the Montage, there will be enough insert effect DSP processors to cover each style and user part, as many as two for every part.

It will be interesting to see (and hear) if the GENOS will make use of the second sample cache interface. A second cache would not only support more tone generation channels, but might be necessary for long, multi-measure musical phrases that are needed for full audio styles (discussed below).

The SWP70 flash memory interface follows the Open NAND FLASH interface (ONFI) standard, the same as solid state drives (SSD). ONFI memory devices can be stacked on a bi-directional tri-state bus, so potentially, the GENOS could support a large amount of internal waveform storage. This flash memory will contain the “expansion memory,” that is, physical memory reserved in flash memory for user waveforms. The expansion flash memory expansion modules (FL512M, FL1024M) are dead, Jim.

If you’re interested in Yamaha AWM2 tone generation, here’s a few patents to get you started:

  • Patent 9,040,800 Musical tone signal generating apparatus, May 26, 2015
  • Patent 8,383,924 Musical tone signal generating apparatus, February 26, 2013
  • Patent 8,389,844 Tone generation apparatus, March 5, 2013
  • Patent 8,957,295 Sound generation apparatus, February 17, 2015
  • Patent 8,035,021 Tone generation apparatus, October 2011
  • Patent 7,692,087 Compressed data structure and apparatus and method related thereto, April 6, 2010

U.S. Patent 8,957,295 is the patent issued for the SWP70 memory interface. U.S. Patent 9,040,800 describes a tone generator with 256 channels — very likely the SWP70.

Pure Analog Circuit

This may seem like old news, too, since Pure Analog Circuit (PAC) debuted in the Yamaha Montage.

Pure Analog Circuit is probably the least understood and least appreciated feature of the Montage. It’s not just better DACs, people. The high speed digital world is very noisy as far as analog audio is concerned. Yamaha separated the analog and digital worlds by putting the DACs and analog electronics on their own printed circuit board away from noisy digital circuits. Yamaha then applied old school engineering to the post-DAC analog circuitry, paying careful attention to old school concerns like board layout for noise minimization and clean power with separate voltage regulation for analog audio. Yamaha’s mid- to high-end products have always been quiet — PAC is pristine.

Since the PAC board is a separate, reusable entity, I could see Yamaha adopting the same board for GENOS.

Styles combining audio and MIDI

Yamaha are constantly in search of greater sonic realism. Existing technologies like Megavoices and Super Articulation 2 (Advanced Element Modeling) reproduce certain musical articulations. However, nothing can really match the real thing, that is, a live instrument played by an experienced professional musician. PG Music Band-in-a-Box (BIAB), for example, uses audio tracks recorded by studio musicians to produce realistic sounding backing tracks. The Digitech TRIO pedal draws on the PG Music technology for its tracks. (“Hello” to the Vancouver BC music technology syndicate.)

Yamaha have applied for and been granted several patents on generating accompaniment using synchronized audio and MIDI tracks. Here is a short list of U.S. patents:

  • Patent 9,147,388 Automatic performance technique using audio waveform data, September 29, 2015
  • Patent 9,040,802 Accompaniment data generating apparatus, May 26, 2015
  • Patent 8,791,350 Accompaniment data generating apparatus, July 29, 2014
  • Application 13/982,476 Accompaniment data generating apparatus, March 12, 2012

There are additional patents and applications. Each patent covers a different aspect of the same basic approach, making different claims (not unusal in patent-land). Yamaha have clearly invested in this area and are staking a claim.

The patents cite four main motivations, quoting:

  1. The ability to produce “actual musical instrument performance, human voices, natural sounds”
  2. To play “automatic accompaniment in which musical tones of an ethnic musical instrument or a musical instrument using a peculiar scale”
  3. To exhibit the “realism of human live performance”
  4. To advance beyond known techniques that “provide automatic performance only of accompaniment phrases of monophony”

Your average guy or gal might say, “Give me something that sounds as natural as Band-in-a-Box.” Yamaha sell into all major world markets, so the ability to play ethnic instruments with proper articulation is an important capability. Human voice, to this point, is limited to looped and one-shot syllables, e.g., jazz scat. The new approach would allow long phrases with natural intonation. [Click on images in this article for higher resolution.]

audio_accompaniment_tracks

Currently, mid- and high-end Yamaha arrangers have “audio styles” where only the rhythm track is audio. The patents cover accompaniment using melodic instruments in addition to rhythm instruments. The melodic audio tracks follow chord and tempo changes just like the current MIDI-based styles. Much of the technical complexity is due to synchronization between audio and MIDI events. Synchronization is troublesome when the audio tracks contain a live performance with rubato. Without good synchronization, the resulting accompaniment doesn’t feel right and sounds sloppy.

Accompaniment from chord chart

This next feature will be very handy. U.S. Patent 9,142,203 is titled “Music data generation based on text-format chord chart,” September 22, 2015. If you use textual chord charts (lyrics plus embedded chord symbols), you will want this!

chord_chart_example

Simply put, the technique described in this patent translates a textual chord chord to an accompaniment. The accompaniment is played back by the arranger. The user can select tempo, style, sections (MAIN, FILL IN) and so forth.

The translator/generator could be embedded in an arranger or it could be implemented by a PC- or tablet-based application. Stay tuned!

Selectively delayed registration changes

A registration is a group of performance parameters such as the right hand voice settings, left hand voice settings, accompaniment settings, and so forth. Mid- and high-end arrangers have eight front panel buttons where each button establishes a set of parameter values (“readout”) when the button is pushed. It’s the player’s job to hit the appropriate button at the appropriate time during a live performance to make voice settings, etc. A player may need a large number of buttons, if a musical performance is complicated.

Usually only a few parameters are different from one registration to the next. Recognizing this, the technique described by U.S. Patent 9,111,514 (“Delayed registration data readout in electronic music apparatus,” August 18, 2015) delays one or more parameter changes when a button is pushed. The user specifies the parameters to be delayed and the delay (such as the passage of some number of beats or measures, etc.) Thus, a single registration can cover the work of multiple individual registrations.

delayed_registration

I’ll have to wait to see the final product to assess the usefulness of this feature. Personally, I’d be happy with a configuration bit to keep OTS buttons from automatically turning on the accompaniment (ACCOMP). Sure would make it easier to use the OTS buttons for voice changes.

Ensembles / divisi

Tyros 5 ensemble voices assign played notes to individual instrument voices in real time, allowing a musician to perform divisi (divided) parts. Tyros 5 ensembles can be tweaked using its “Ensemble Voice Key Assign Type List.” Types include open, closed, and incremental voice assignment. U.S. Patent 9,384,717, titled “Tone generation assigning apparatus and method” and published July 5, 2016, extends Tyros 5 ensemble voice assignment.

The technique described in 9,384,717 gives the musician more control over part assignment through rules: target depressed key, priority rule, number of tones to generated, note range, etc. The rules handle common cases like splitting a single note to two or more voices.

ensemble_rules

These extensions could lead to some serious fun! I didn’t feel like the Tyros 5 ensemble feature was sufficiently smart and placed too many demands on the average player, i.e., less-than-talented me. The rules offer the opportunity to shift the mental finger work to software and perhaps could lead to more intuitive ensemble play. Neat.

Voice synthesis

As I alluded to earlier, arrangers make relatively primitive use of the human voice. Waveforms are usually limited to sustained (looped) or short (one-shot) syllables.

Yamaha have invested a substantial amount of money into the VOCALOID technology. VOCALOID draws on a singer database of syllable waveforms and performs some very heavy computation to “stitch” the individual waveforms together. The stitching is like a higher quality, non-real time version of Articulated Element Modeling (AEM).

VOCALOID was developed through a joint research project (led by Kenmochi Hideki) between Yamaha and the Music Technology Group (MTG) of the Universitat Pompeu Fabra in Barcelona, Spain. VOCALOID grew from early work by J. Bonada and X. Serra. (See “Synthesis of the Singing Voice by Performance Sampling and Spectral Models.”) More recent research has stretched synthesis from the human voice to musical instruments. Yamaha hold many, many patents on the VOCALOID technology.

Patent 9,355,634, titled “Voice synthesis device, voice synthesis method,” is a recent patent concerning voice synthesis (May 31, 2016). It, too, draws from a database of prerecorded syllables. The human interface is based on the notion of a “retake,” such as a producer might ask a singer to make in a recording studio using directives like “put more emphasis on the first syllable.” The retake concept eliminates a lot of the “wonky-ness” of the VOCALOID human interface. (If you’ve tried VOCALOID, you know what I mean!) The synthesis system sings lyrics based on directions from you — the producer.

An interface like this would make voice synthesis easier to use, possibly by novices or non-technically oriented musicians. The big question in my mind is whether voice synthesis and editing can be sped up and made real time. Still, wouldn’t it be cool if you could teach your arranger workstation to sing?

Music minus one

This work was conducted jointly with the MTG at the Universitat Pompeu Fabra. A few of the investigators were also involved in VOCALOID. Quoting, “The goal of the project was to develop practical methods to produce minus-one mixes of commercially available western popular music signals. Minus-one mixes are versions of music signals where all instruments except the targeted one are present.”

This is not good old center cancellation. The goal is to remove any individual instrument from a mix regardless of placement in the stereo field. You can hear a demo at http://d-kitamura.sakura.ne.jp/en/demo_deformation_en.htm.

I doubt if this technique will appear on an arranger; the computational requirements are too high and the method is not real time. However, “music minus-one” is very appealing to your average player (that is, me). My practice regimen includes playing with backing tracks. I would love to be able to play with any commercial tune on whim.

There are patents:

  • US Patent 9,002,035 Graphical audio signal control
  • US Patent 9,224,406 Technique for estimating particular audio component
  • US Patent 9,070,370 Technique for suppressing particular audio component

and there are scientific papers:

  • “Audio Source Separation for Music in Low-latency and High-latency Scenarios”, Ricard Marxer Pinon, Doctoral dissertation, Universitat Pompeu Fabra, Barcelona, 2013.
  • D. Kitamura, et al., “Music signal separation by supervised nonnegative
    matrix factorization with basis deformation,” Proc. DSP 2013, T3P(C)-1, 2013.
  • D. Kitamura, et al., “Robust Music Signal Separation Based on Supervised Nonnegative Matrix Factorization with Prevention of Basis Sharing”, ISSPIT, December 2013.

Music analysis

Yamaha have put considerable resources into what I would call “music analysis.” These technologies may not (probably will not) make it into an arranger keyboard. They are better suited for PC- or tablet-based applications.

I think we have seen the fruits of some of this labor in the Yamaha Chord Tracker iPad/iPhone application. Chord Tracker identifies tempo, beats, musical sections and chords within an audio song from your music library. It displays the extracted info in a simple chord chart and can even send the extracted “lead sheet” to your arranger. The arranger plays back the “lead sheet” as an accompaniment using the selected style.

We’re probably both wondering if Chord Tracker will integrate with the chord chart tool described above. Stay tuned.

Yamaha Patent 9,378,719 (June 28, 2016) is a “Technique for analyzing rhythm structure of music audio data.” Patent 9,117,432 (August 25, 2015) is an “Apparatus and method for detecting chords.” I wouldn’t be surprised if Chord Tracker draws from these two patents.

Yamaha has also investigated similarity measures and synchronized score display:

  • Patent 9,053,696 Searching for a tone data set based on a degree of similarity to a rhythm pattern, June 9, 2015
  • Patent 9,006,551 Musical performance-related information output device, April 14, 2015
  • Patent 9,275,616 Associating musical score image data and logical musical score data, March 1, 2016

I’m not sure where Yamaha is going with similarity measures and searching. Will they use similarity measures to selected accompaniment phrases? Who knows?

The work on score display synchronizes the display of the appropriate part of a musical score with its live or recorded performance. These techniques may be more appropriate to musical education and training, particularly for traditional brass, string and woodwind players. Yamaha derives considerable revenue from traditional instruments and this is perhaps a way to enhance their “ecosystem” for traditional acoustic instruments.

Score display is one possible application of Yamaha’s patented technique to transmit performance data via near-ultrasonic sound. The technique borrows one or more tone generation channels to generate the near-ultrasonic data signal. See my earlier post about U.S. Patent 8,779,267 for more details.

So long for now!

That’s it! I hope you enjoyed this brief tour through a few of Yamaha’s recent patent grants and filings.

If you want more information about a particular patent, then cruise on over the the U.S. Patent and Trademark Office (USPTO) web site. Navigate to patent search and plug in the patent number.

Copyright © 2017 Paul J. Drongowski

Won’t be long, yeah!

Winter NAMM 2017 starts in two weeks (January 19). As usual, we gear freaks can’t wait to get our annual new product fix!

Roland jumped the field and announced a few new products at the 2017 Consumer Electronics Show (CES). They appear to be rolling out a new consumer-oriented product line, “GO:”, for amateur musicians and music makers.

Roland announced two new keyboards for beginning players: the GO:KEYS (G-61K and G-61KL) and the GO:PIANO. Both products target the entry-level market currently dominated by Yamaha and Casio. This is a smart business move as the entry-level segment moves a lot of units and offerings in this segment have been getting stale. Here are estimated USA sales statistics for 2014 in the “portable keyboard” segments:

    Category                       Units            Retail value
    -----------------------------  ---------------  -------------
    Portable keyboards under $199    656,000 units  $ 64,000,000
    Portable keyboards over $199     350,000 units  $123,000,000
    Total portable keyboards       1,006,000 units  $187,000,000

    (Source: NAMM)

Unit volume is high, but price and margins are razor thin. Keyboards in the “under $199” category are sold mainly in big box stores, not musical instrument retailers. So, it will be interesting to see where the new Roland keyboards are sold.

The GO:KEYS is most similar to an entry-level arranger keyboard. Estimated street price is $299. Roland is selling two models: a model with Bluetooth support and a model without. Probably depends on their ability to get RF type acceptance in a country or region. The GO:KEYS claims General MIDI 2 (GM2) support among 500 “pro-quality” sounds. The GM2 tone set consists of 256 melodic instruments and nine drum kits. I produced quite a few decent backing tracks using the Roland GM2 sound set on its RD-300GX stage piano. If Roland adopted this set, then the GO:KEYS should sound pretty decent (at least through external monitors rather than its internal speakers). No manual yet so it’s hard to say specifically what other sounds are included. Even if they recycled some chestnuts from the old JV/XP/XV, there is hope.

roland-go_keys

The Roland GO:PIANO is, ta-da, a portable piano. This product has the Yamaha Piaggero line in its cross-hairs. The estimated street price is $329. Again, no manual, so it’s hard to assess the feature set. Pricing on both products places them at the higher end of the entry-level market. The inclusion of Bluetooth support at this price point is a significant differentiator.

roland_go_piano

Both the GO:KEYS and GO:PIANO are battery powered (six AA batteries) in addition to an AC adapter. Both products use one-off fixed field LCD text and graphics like the lower cost Yamaha and Casio models. The key beds look decent, but we will have to play them in order to assess feel and quality. At least the keys are full size — not mini-keys, thank you.

If the Roland sounds are indeed up to snuff, Roland may be able to take sales away from Yamaha and Casio. Yamaha has been coasting with its entry-level sound set for over a decade and the recent PSR-E453 refresh did little to rejuvenate the entry-level segment. It will be interesting to see if Roland can win sales and spur innovation at the low end.

The GO:MIXER is positioned as an audio mixer for your mobile phone. It is USB powered, however, with no battery option. The GO:MIXER has guitar, microphone, instrument and media player inputs with associated mixing level control. There is a stereo monitor output as well as a “center cancel” feature. The estimated street price is $99USD.

roland_gomixer

Although Roland promote it for video production, I could see musicians using the GO:MIXER for a quick mix in the field. It certainly has enough inputs that a small group of pals could plug in and jam away.

New Yamaha workstation at NAMM 2016?

True gearheads are already making predictions and plans for 2016 Winter NAMM, January 21-24, 2016. Winter NAMM rumors abound including “Montage,” the rumored name for the rumored new Yamaha synthesizer workstation.

See the list of new waveforms in the Montage and read my initial review of the Montage8. Update: May 10, 2016.

Find the latest links, pictures, rumors and facts here . Update: January 21, 2016.

Check out some new thoughts about the rumored workstation and preliminary comments . Update: January 18, 2016.

Many folks — myself included — anticipate the release of a new Yamaha synthesizer workstation at the next NAMM. Much has been made of the registered trademark “Montage.” I don’t really care too much about what they call it, as I care about what it will do.

Last month, I posted two articles about the new Yamaha tone generation chip called “SWP70”:

This chip made its first appearance in the new PSR-S770 and PSR-S970 arranger workstations. Lest anyone scoff, the S770 and S970 produce Motif-caliber sounds including the REAL DISTORTION effects added to the Motif XF by the v1.5 update. The previous tone generator (SWP51L) is used throughout the mid- and upper-range Yamaha keyboard products including Clavinova, MOX/MOXF, Motif XS/XF, and Tyros 4/5. The number of tone generator chips varies by product specification and, most notably, sets the maximum available polyphony. A new tone generator chip is a pretty big deal since it will have an impact on all mid- and high-grade electronic instruments across product lines.

My earlier article about the SWP70 is written from the perspective of a computer architect and is way too nerdy for normal people. 🙂 Let me break it down.

Musicians using VST plug-ins within a PC-based DAW are familiar with the concept of sample streaming. In the quest for greater realism and articulation, sample libraries have become huge. These libraries simply cannot fit into fast random access memory (RAM) for playback. As a work-around, a software instrument reads samples from a drive-based library on demand and only a small part of the entire library is resident in RAM at any given time. The process is often called “sample streaming” because the software instrument streams in the samples on demand from a large fast secondary memory like a Solid-State Drive (SSD). The Korg Kronos workstation caught everyone’s attention because it incorporates an x86-based software system that streams samples from an SSD. (For Kronos-related articles, look here and here.)

The SWP70 combines streaming with tone generation. It does not, however, use an SSD for storage. Rather, it subsumes the functionality of the SSD. A moment to explain…

An SSD consists of three major subsystems: SATA controller, temporary storage cache (RAM) and one or more NAND flash memory chips. The NAND flash memory chips typically adhere to the Open NAND Flash Interface (ONFI) standard. This allows expansion and standardized configurability. The SATA controller exchanges commands and data with a computer using the SATA bus protocol. The temporary storage cache holds data which is pre-read (cached) from the NAND flash chips. Caching is required because random access read to NAND flash is too slow; sequential paged access is much faster. Data must be prefetched in order to achieve anything like SATA 1 (2 or 3) transfer speed.

The SWP70 subsumes the SSD functionality. It has its own memory controller and has a side memory port to its own RAM for caching samples. The SWP70 reads samples from its ONFI-compatible NAND flash memory bus and stores the samples in its cache. The tone generation circuitry reads the samples from the cache when it needs them. The SWP70 solution is, effectively, sample streaming without the added cost and latency of SATA bus transfers. The samples coming into the SWP70 from flash are compressed, by the way, and the SWP70 decompresses them.

The SWP70 will very likely make an appearance in the new Yamaha synthesizer workstation. The S770 and S970 do not make full use of the SWP70, so we have yet to see what this chip is fully capable of. We can definitely expect:

  • Much larger wave memory (4GBytes minimum)
  • Greater polyphony (256 voices or more)
  • More simultaneous DSP effects (32 units or more)
  • The demise of the expensive expansion flash DIMMs

I would simply love it if the new workstation implemented some form of Super Articulation 2 voices (now supported by Tyros 5). The raw resources are there.

User-installed expansion memory may be a thing of the past. The current DIMMs plug into a two channel, full parallel memory interface. That interface is gone and the SWP70 communicates with flash NAND through an ONFI-compatible interface. The Motif and Tyros follow-ons will likely reserve space for user samples and expansion packs in built-in flash memory just like the new mid-range PSRs.

What does Yamaha intend to do with all of this polyphony? Current high-end models like the Tyros 5 use two tone generation chips. Yamaha could replace both chips with a single SWP70 and pocket the savings.

Another possibility is to provide advanced features for musical composition that combine MIDI and audio phrases. Here is a list of technologies covered by recent Yamaha patents and patent applications:

  • Beat detection and tracking
  • Chord detection
  • Synchronized playback of MIDI and audio
  • Combined audio/MIDI accompaniment (time-stretch and pitch-shift)
  • Object-oriented phrase-based composition on a time-line
  • Accompaniment generation from chord chart
  • Display musical score synchronized with audio accompaniment
  • Phrase analysis and selection (via similarity index)
  • Near ultra-sonic communication of control information
  • Search for rhythm pattern similar to reference pattern

A few of these technologies are covered by more than one patent — recurring themes, if you will. I could imagine a screen-based composition system that combines audio and MIDI phrases which are automatically selected from a database. The phrases are transparently time-stretched and pitch-shifted. Some of the compositional aids may be implemented in the workstation while others are tablet-based. The tablet communicates with the workstation over near ultra-sonic sound (no wires, no Bluetooth, no wi-fi, no time lag).

Sample-based tone generators already perform pitch-shifting. That’s how a single sample is stretched across multiple keys. A musical phrase can be pitch-shifted in the same way. As to time-stretching, stay tuned.

Some of these features, like accompaniment generation from a textual chord chart, are more likely to appear in a future arranger workstation product. Making product-specific predictions is a risky business, especially if you want to get it right!

Yamaha — the business — is keenly interested in growth and expanding markets. Management sees opportunity in growth markets like China. The need to combine audio phrases with MIDI is driven by non-Western music: time signatures other than 3/4 or 4/4, different scales, different playing techniques and articulations. These concerns are perhaps more relevant to the arranger product lines. However, phrase-based composition that manipulates and warps audio and MIDI transparently is a basic feature of many DAWs. (Think “Ableton Live.”)

One final theme seems to recur. Yamaha appear to be interested in analyzing and accompanying non-keyboard instruments. The market for guitar-driven accompaniment is much wider and deeper than today’s arranger workstations and is a lucrative target.

Here are links to a few earlier articles, including speculation about the new Yamaha synthesizer workstation:

These articles link to further background information. Of course, we’ll know a lot more once Winter NAMM 2016 is underway!

All site content Copyright © Paul J. Drongowski unless otherwise indicated.

Copy PSR DSP effects (part 4)

This is part 4 of a series of articles about DSP effects for electric pianos and other electrified instruments like guitar. The first three articles are:

This article covers two more techniques that should help you create and apply DSP effects to PSR/Tyros voices.

Beg, borrow and steal

As Picasso once said, “When there’s anything to steal, I steal.” I’m not encouraging larcency or piracy, but when there’s a good effect in an OTS or voice, copy and paste is the way to go.

I like writing these blog posts because they encourage me to learn more about PSR/Tyros features that I might have ignored or overlooked. Such is the case with the section titled “Disabling Automatic Selection of Voice Sets” in the Reference Manual. This features gives us a way to selectively copy certain aspects of a voice to another (new) voice.

This feature is like a “mini-freeze” that applies solely to VOICE SET, not entire registrations. Navigate to:

    FUNCTION > [E] REGIST SEQUENCE/FREEZE/VOICE SET

then TAB over to the VOICE SET page. There are four buttons at the bottom of the page controlling, respectively, four aspects of voice loading when a voice is selected:

    VOICE
    EFFECT
    EQ
    HARMONY/ECHO

When a button is ON, the corresponding voice parameter settings are loaded automatically from the selected voice. When a button is OFF, the corresponding voice parameters settings are not loaded.

So, if we set the button for EFFECT to OFF, we essentially “freeze” the current effect settings. When we load a new voice, the effects remain the same. This gives us a poor man’s copy and paste between voices.

Let’s say that we like the distortion effect on the “Clavi” voice and want to apply it to “VintageEP”. First, I load the Clavi voice to call up the DSP effect. Then, I navigate to the VOICE SET page (as described above) and turn the EFFECT button OFF. This freezes the effect part of the voice programming. Then, I select the VintageEP voice. Voila, the VintageEP voice plays using the distortion effect that was frozen.

Stop! Wait a minute!

Once you save the VintageEP voice to the USB drive or an OTS button, be sure to unfreeze the EFFECT aspect of voice loading. If you don’t do this, you will surely wonder why all of the voices you load are distorted!

Hey, where’s the loot?

The built-in voices are the most obvious source of inspiration for new basic voice plus effect combinations. Yamaha need to maintain backward compatible voices, however, and the older voices such as the electric pianos may not use the latest and greatest effects (e.g., REAL DISTORTION). The guitar voices tend to turn over more quickly and adopt the latest effects.

Backward compatibility is less of an issue for the OTS voices within styles. You are more likely to find new and interesting effects under the OTS buttons. Take the built-in “WahClavi” voice, for example. The built-in voice uses the old CLAVI TC.WAH effect. The “WahClavi” voice in the JazzFunk style, on the other hand, uses the new REAL DISTORTION multi-effect MLT CR WAH (Multi FX Crunch Wah).

The following table is a list of OTS voices showing the parent style and DSP effect. Follow this map to find buried treasure!

Voice            Style          S950 effect   Tyros 5 effect
---------------  -------------  ------------  -------------------------------
GrungeGuitar     JazzFunk       AMP1 HEAVY    British Combo Heavy
OverdriveWah     JazzFunk       MLT CR WAH    Multi FX Crunch Wah
VintageAmp       Soul           V_DIST SOLID  V_Dist Solid
Slapback         MotorCity      V_DIST ROCA   V_Dist Roca
SingleCoilClean  Live8Beat      CMP+OD+TDLY4  Compressor+Overdrive+TempoDelay4
JazzClean        KoolShuffle    V_DST JZ CLN  V_DistJz Cln
StageLead        HardRock       MLT DS SOLO   Multi FX Distortion Solo
EarlyLead        FunkPopRock    TEMPO AT.WAH  Tempo At.Wah+
MetalMaster      ContempRock    ST AMP DS     Small Stereo Distortion
ElectroAcoustic  AcousticRock   AMP1 CLASSIC  British Combo Classic
BluesyNight      70sGlamPiano   ST AMP VT     Small Stereo Vintage Amp
PureVintage      60sRock&Roll   MLT OLD DLY   Multi FX Oldies Delay

VintageEP        SoulBrothers   AMP1 CLASSIC  British Combo Classic
WahClavi         JazzFunk       MLT CR WAH    Multi FX Crunch Wah
SuitcaseEP       Live8Beat      CELESTE2      Celeste 2
ElectricPiano    FunkyGospel    EP AUTOPAN    EP Autopan
CP80             FunkPopRock    T_PHASER1     T Phaser 1
JazzVibes        DetroitPop2    VIBE VIBRATE  Vibe Vibrato
VintageEP        60sPopRock     EP TREMOLO    EP Tremolo

HoldItFast       LiveSoulBand   DIST SOFT2    Distortion Soft 2
WhiterBars       Soul           V_DIST CLS S  V_Dist Cls S
WhiterBarsFast   GospelSwing    ST AMP CLEAN  St Amp Clean
CurvedBars       MotorCity      ST 3BAND EQ   St 3Band EQ
EvenBars         FunkyGospel    ST 3BAND EQ   St 3Band EQ
AllBarsPhase     FunkPopRock    PHASER2       Phaser 2
ClassicBars      BluesRock      ST AMP CLEAN  St Amp Clean
Organ-a-Gogo     70sDisco2      V_DIST TWIN   V_Dist Twin
R&B Tremolo      60sVintageRock DIST HARD2    Distortion Hard 2
OrganFlutes      60sPopRock     AMP2 CLEAN    British Legend Clean
OrganFlutes      6-8SlowRock    ROTARY SP1    Dual Rot BRT

GrowlSax         SoulBrothers   V_DST S+DLY   V Distortion Soft + Delay
GrowlSax         MotorCity      V_DST H+DLY   V Distortion Hard + Delay
RockSax          LiveSoulBand   DST+DELAY1    Distortion + Delay 1
RockSax          HardRock       ST AMP CLEAN  St Amp Clean
Harmonica        6-8Soul        TEMPO AT.WAH  Tempo At.Wah+

Use the poor man’s copy and paste method to mix and match a basic voice sound with a DSP effect. The treasure map demonstrates how the Yamaha style programmers make use of the workstation’s sonic resources. There’s a lot to learn here!

Dry/Wet mix

I like to change voices by hitting the OTS buttons while jamming along with a tune. I have created more than 50 styles with customized OTS buttons to cover my current repetoire. The OTS buttons select the voice and effect combinations that are the most approprtiate for specific tunes (appropriate to my ears anyway).

Unfortunately, the kind of OTS voice and effect informaton that can be stored is limited by the S950’s operating system. (See the Voice Effect, Voice Set, and Mixing Console sections of the Parameter Chart in the Data List manual for the exact details.) An OTS button remembers:

  • DSP effect type (insertion type)
  • DSP ON/OFF
  • DSP variation ON/OFF
  • DSP variation value
  • DSP depth

for the RIGHT1, RIGHT2 and LEFT parts.

If you cast your mind back to Part 1, you know that there are a lot of parameters behind each effect. These parameters cannot be directly captured in an OTS button, which is why they must be stored in a USER EFFECT memory location as described in Part 2. You do get a fly-speck of tweakability by modifying the DSP variation value. Unfortunately, the parameter type is fixed.

The OTS restrictions are relieved or eliminated in the PSR-S970. Again, please see the Parameter Chart in the Data List manual.

Fortunately, OTS remembers DSP depth. The DSP depth controls the “dry/wet” mix, that is, the amount of uneffected (dry) and effected (wet) signal that is mixed together and sent further along (usually to the system-level chorus and/or reverb blocks).

Let’s say that you added a heavy distortion sound to the “SuitcaseEP” voice and you want to reduce the amount of distortion without changing the tone. (Guitar distortion is often waaaay too much for electric piano.) Simply dial down the DSP depth. This increases the amount of dry (clean) electric piano sound and decreases the amount of wet (distorted) electric piano sound. Voila, an electric piano with a bit of grit, not a fuzzed out shredder’s delight.

Here are the parameters for the DISTORTION presets DIST SOFT1 and DIST SOFT2.

                       DIST SOFT1  DIST SOFT2
                       ----------  ----------
    Drive                 16           7
    Amp Type             Tube        Combo
    LPF Cutoff          4.5 KHz     3.6 KHz
    Output Level          64          82
    Dry/Wet              D44>W      D<W63
    Edge (Clip Curve)     49          40

The built-in preset “Clavi” voice uses DIST SOFT1 to get its biting tone. Note that the DIST SOFT1 dry/wet mix has more dry signal than wet and that the DIST SOFT2 dry/wet mix has more wet signal than dry.

Here’s where things are cool, confusing, or both. The S950 seems to know when a DSP effect has a predefined dry/wet mix parameter. The parameter value tracks the DSP depth knob in the Mixing Console. Cool. The DSP depth knob is calibrated from 0 to 127 while the dry/wet parameter is calibrated from full dry (D63>W) to full wet (D<W63). Confusing. Internally, a 50-50 dry/wet mix (D=W) is represented by the value 64. The dry/wet mix is 50-50 (D=W) when the mixing console DSP depth knob is set to 64; the knob determines the internal value. (Pan gets munged in a similar way.)

As an exercise, I suggest applying the distortion effect in the built-in “Clavi” voice to “SuitcaseEP.” Then, use the DSP depth (dry/wet mix) to dial back (or dial up!) the distortion to taste.

A loose end

Some of you probably noticed that I didn’t say much about the “Wah Pedal” parameter belonging to the REAL DISTORTION multi-effect algorithm. This parameter can be swept by an XG “assignable controller.”

I didn’t say much about the “Wah Pedal” parameter because I was hoping to find a way to control this parameter from either the expression pedal input or an external MIDI controller. It may be possible to set up external control if a controller can utter the right SysEx mumbo-jumbo to set up an XG assignable controller. The process looks beastly and not very practical.

However, the S970 and Tyros 5 are capable of sweeping the wah pedal parameter. Please see the reference manual concerning “Footswitch / Foot Controller Settings”.

PSR effects for electric piano (Part 1)

A common complaint about the electric pianos on the Yamaha PSR arranger workstations is their lack of “guts” or “grit.” The voice samples are reasonably good, but the effects programming is vanilla and way too polite, especially for rock and soul styles. Here is a table showing the default DSP effect for some of the electric piano voices in the PSR-S950:

    PSR-S950 voice  Category     Effect
    --------------  ----------   -----------------------
    SparkleStack    CHORUS       CHORUS3
    SweetDX         CHORUS       CHORUS3
    BalladDX        CHORUS       ENS DETUNE1
    DX Dynamics     CHORUS       CHORUS2
    BalladBells     CHORUS       CHORUS3
    SuitcaseEP      CHORUS       CELESTE2
    VintageEP       TREMOLO      EP TREMOLO    [DSP off]
    CP80            CHORUS       CHORUS3
    StageEP         CHORUS       CELESTE2
    SmoothTine      SPATIAL      EP AUTO PAN
    ElectricPiano   SPATIAL      EP AUTO PAN   [DSP off]
    Clavi           DISTORTION   DIST SOFT1
    WahClavi        WAH TCH/PDL  CLAVI TC.WAH
    PhaseClavi      PHASER       EP PHASER2

You can see that most of the voices use a chorus effect. In two cases, the DSP effect is turned off by default. (You need to turn it on using the [DSP] front panel button.) The Clavinet voices are a little more fun and use distortion, wah and phaser.

Chorus does not add much “heft” to a voice and it doesn’t add grit. Compression, mid-range boost (EQ) and overdrive are better choices when you need a punchy and/or grungy electric piano sound.

Let’s take a look at the effects programming for a few electric piano voices on the Yamaha MOX synthesizer workstation. The basic voices drive two insert effects connected in series:

    MOX voice             Insert A     Insert B
    --------------------  -----------  -----------
    Crunchy Comp          MltBndComp   CompDistDly
    Vintage Case          AmpSim 2     Auto Pan
    Chorus Hard           ClassicComp  SPX Chorus
    Drive EP AS1          AmpSim 2     Auto Pan
    Natural Wurli         AmpSim 1     Tremolo
    Wurli Distortion AS1  Tremolo      CompDistDly

On the MOX, every voice uses compression, amp simulation or distortion, even the voices employing the evergreen tremolo, pan and chorus effects.

At this point, PSR users tend to throw up their hands and say, “Well, that’s the Motif series!” and back away. Yamaha — bless them — share technology between workstation products. Quite often, you can find the equivalent PSR effect algorithm for an MOX (MOXF) or Motif algorithm.

Consider the MOX “AmpSim2” algorithm. This algorithm shares the same parameters as the PSR “DISTORTION AMP SIM2” algorithm. Here is a table showing the corresponence between MOX and PSR.

    MOX parameter  PSR parameter  MOX value
    -------------  -------------  ---------
    Preset         n/a            Stack1
    AmpType        AMP Type       Tube
    OverDr         Drive          16
    OutLvl         Output Level   70
    LPF            LPF Cutoff     6.3KHz
    Dry/Wet        Dry/Wet        D<W30

The parameter values given here are taken from the MOX “Drive EP AS1” voice. Bring up a PSR voice like “VintageEP,” edit its DSP effect and replace the tremolo effect with “AMP SIM2.” Plug in these values, listen and tweak!

My second example is taken from the MOX “Natural Wurli” voice. The MOX effect algorithm name is “Amp Sim1”. The equivalent PSR effect algorithm is “DISTORTION V_DIST WARM” and its siblings. Here is the equivalency table:

    MOX parameter  PSR parameter  MOX value
    -------------  -------------  ---------
    Preset         n/a            Stack2
    OverDr         Overdrive      2%
    Device         Device         Vintage tube
    Speaker        Speaker        Stack
    Presence       Presence       +10
    OutLvl         Output Level   53%
    Dry/Wet        Dry/Wet        D<W1

Again, change the PSR DSP effect to “V_DIST WARM” and plug in the values. Then, tweak away.

The final example is a multi-effect taken from the MOX “Wurli Distortion AS1” voice. The MOX effect algorithm is “CompDistDly” that is a compressor, distortion and delay effect chain. The equivalency table is:

    MOX parameter  PSR parameter         MOX value
    -------------  --------------------  ---------
    Preset         n/a                   Hard1
    OverDr         Overdrive             15%
    Device         Vin_tube              Vintage tube
    Speaker        Stack                 Stack
    Presence       Presence              +10
    DelayL         Delay Time L          307.3ms
    DelayR         Delay Time R          271.7ms
    FBTime         Delay Feedback Time   306.6ms
    FBLevel        Delay Feedback Level  +31
    FBHiDmp        Feedback High Dump    0.8
    OutLvl         Output Level          22%
    DlyMix         Delay Mix             0
    Compress       n/a                   -29dB
    Dry/Wet        Dry/Wet               D<W12

The almost equivalent PSR effect algorithm is “DISTORTION+ V_DST H+DLY”. The PSR algorithm is missing the compression component (parameter). If you want compression, then consider one of the other PSR distortion algorithms with mono delay.

Keep thinking “multi FX.” I’m going to visit the REAl DISTORTION multi FX algorithm in a future post.

Some of the MOX voices use VCM effects. I didn’t deconstruct the voices with VCM effects because my S950 doesn’t have them. However, if you have VCM effects, for heaven’s sake, use them!

Learn how to save your new creation in Editing and Saving PSR Effects (Part 2).

PSR effects for electric piano (Part 1)
Editing and saving PSR effects (Part 2)
Multi-effects for electric piano (Part 3)
Copy PSR DSP effects (part 4)

The SWP70 tone generator

As I mentioned in an earlier post, the Yamaha PSR-S770 and PSR-S970 arranger workstations have a new tone generator (TG) integrated circuit (IC) — the SWP70. (“SWP” stands for “Standard Wave Processor.”) The SWP70 is a new TG family in a long line of Yamaha tone generators. The SWP70 replaces the SWP51L, which has been the mainstay in recent generations of Tyros, upper range PSR, Motif, and MOX series workstations.

The SWP70 has much in common with the SWP51L, but also some very significant differences. The SWP70’s external clock crystal frequency is 22.5792 MHz versus 11.2896 MHz for the SWP51L. This funky looking clock rate is a multiple of 44,100 Hz:

    22.5792MHz = 44,100Hz * 512

Samples are transferred to the DAC, etc. at a multiple of 44,100 Hz (Fs). Thus, it makes sense to derive Fs and its multiples from the chip-level master clock. The higher crystal frequency and faster memory read clocks lead me to believe that the SWP70 is clocked twice as fast as the SWP51L.

I am comparing SWP characteristics as deployed in the S970 (SWP70) and the S950 (SWP51L) workstations. This keeps the basis of comparison even although many characteristics (clock rates, DSP RAM size) are the same in higher end models like Tyros 5 or Motif. Higher end models employ two SWPs in master/slave relationship and both SWPs share the same wave memory. For more information about the PSR-S970 internal design, look here.

Five interfaces are essentially the same as the SWP51L:

  1. CPU interface: Communicate with the Main CPU (e.g., Renesas SH7731) via the parallel CPU bus.
  2. Serial audio: Send/receive audio data to/from the DAC, audio ADCs, and main CPU.
  3. Clock interface: Synchronize serial audio data transfers (generate multiples of Fs).
  4. DSP SDRAM interface: Store working data for effect processing.
  5. EBUS interface: Receive controller data messages (e.g., pedal input, keyboard input, pitch bend, modulation, live knobs, etc.) from front panel processors.

The DSP SDRAM is the same size: 4Mx16bits (8MBytes). The SWP70 read clock is 95.9616 MHz, while the SWP51L read clock is 45.1584 MHz. This is more evidence for a higher internal clock frequency.

The Tyros 4, Tyros 5 and S950 have an auxiliary DSP processor for vocal harmony. The microphone analog-to-digital (ADC) converter is routed directly to the auxiliary processor. Prior to these models, the microphone ADC is connected to the tone generator. With the SWP70, the S970’s microphone ADC is once again routed to the SWP70 and the auxiliary processor disappears from the design. Thus, vocal harmony processing (fully or partially) is located in the SWP70. See my post about SSP1 and SSP2 for further details.

The biggest change is the wave memory interface.

A little history is in order. The SWP51L (and its ancestors) were designed in the era of mask programmable ROM. I contend that tone generation is memory bandwidth limited and the earlier interface design is driven by the need for speed. The SWP51L (due to its evolved history) has two independent wave memory channels (HIGH and LOW). Each channel has a parallel address bus (32 bits) and a parallel data bus (16 bits). The two channels account for over 100 pins. (System cost is proportional to pin count.) The user-installed, 512/1024MB flash DIMMs plug directly onto the two channels.

The SWP70 wave memory interface takes advantage of new NAND flash memory technology. The interface is described in US patent application 2014/0123835 and is covered by Japanese patent 2012-244002. I analyzed the US patent application in an earlier post.

The SWP70 retains the HIGH port and LOW port structure. Each port communicates with an 8Gbit Spansion S34ML08G101TFI000 NAND flash device. Address and data are both communicated over an 8-bit serialized bus. This technique substantially decreases pin count and the resulting board-/system-level costs. Smart work.

I did not anticipate, however, the introduction of a new parallel memory interface called “wave-work”. The wave work interface communicates with a 16Mx16bit (32MBytes) Winbond W9825G6JH-6 SDRAM. The read clock is 95.9616 MHz.

The purpose of the wave work SDRAM is revealed by US Patent 9,040,800. This patent discloses a compression algorithm that is compatible with serialized access to the wave memory. The wave work SDRAM is a cache for compressed samples. The characteristics of the Spansion memory device give us a clue as to why a cache is required:

    Block erase time               3.5ms    Horrible (relative to SDRAM)
    Write time                     200us    Terrible
    Random access read time         30us    Bad
    Sequential access read time     25ns    Very good

As the patent explains, two (or more) samples are required to perform the interpolation while pitch-shifting. If there is only one tone generation channel, access is paged sequential. However, random access is required when there are multiple tone generation channels. (The patent mentions 256 channels.) Each channel may be playing a different voice or a different multi-sample within the same voice. One simply cannot sustain high polyphony through random access alone. The cache speeds up access to recently used pages of uncompressed samples.

The wave work interface takes additional pins, thus adding to board- and system-level costs. The overall pin count is still lower when compared to SWP51L. The penalty must be paid in order to use contemporary NAND flash devices with a serialized bus. This is the price for catching the current (and future) memory technology curve.

A few SWP70-related printed circuit board (PCB) positions are unpopulated (i.e., IC not installed) in the PSR-S970. There is an unpopulated position for a second Winbond W9825G6JH-6 wave work SDRAM which would expand the wave work memory to 32Mx16bit (64MBytes). A larger cache would be needed to support additional tone generation channels. Perhaps only half of the tone generation channels are enabled in the mid-grade PSR-S970 workstation.

There is what appears to a second separate wave work interface that is completely unpopulated. The intended memory device is a Winbond W9825G6JH-6, which is consistent with the existing wave work interface.

The PSR-S970 also has a stubbed out interface that is similar to the DSP SDRAM interface. The existing DSP SDRAM signals are labeled “H” for HIGH while the unused interface is labeled “L” for LOW. Perhaps only half of the hardware DSP processors are enabled for the mid-grade S970, waiting to be activated in future high-end Tyros and Motif products.

I refer to future high end products by the names of the current product lines. Yamaha may choose to rebrand future products (e.g., the much-rumored “Montage” trademark).

The Spansion S34ML08G2 8-Gb NAND device is Open NAND Flash Interface (ONFI) 1.0 compliant. The S34ML08G2 device is a dual-die stack of two S34ML04G2 die. The 8-bit I/O bus is tri-state allowing expansion e.g., multiple memory devices sharing the same I/O bus and control signals with at most device enabled at any time. The SWP70 has additional chip select pins that would support this kind of expansion. The current expansion flash DIMMs will no longer be needed or used.

In this note, I concentrated on observations and fact, not speculation about future products. I’ll leave that fun for another day!

All site content is Copyright © Paul J. Drongowski unless indicated otherwise.

SSP1 and SSP2: Designated hitter

One notable absence from the Yamaha PSR-S970 design is the “SSP2” integrated circuit (IC) which handles vocal harmony processing. The SSP1 and SSP2 appeared in the Tyros series and PSR series coincident with Vocal Harmony 2.

For you signal sleuths, the PSR-S950 and Tyros 5 microphone input is routed to an analog-to-digital converter (ADC) where the analog signal is sampled and digitized. The digital sample stream is sent to the SSP2 IC. The firmware munges on the samples and voila, the SSP2 produces a vocal harmony signal that is mixed with samples from the tone generator, etc. The SSP2 sends its results to the TG where effects and mixing are performed. The TG sends its output to the digital-to-analog converters (DAC) and digital amplifiers. The Tyros 4 has the same signal flow using an earlier model “SSP1” processor instead.

Previous machines with vocal harmony (e.g., Tyros 3 and earlier, PSR-S910 and earlier), routed the digitized microphone stream to a tone generator (TG) IC such as the SWP51L. Presumably, vocal harmony processing was performed in the TG IC. With the brand new SWP70 tone generator in the S970, the digitized microphone stream is sent to the SWP70. Looks like vocal harmony processing is folded into the SWP70 TG.

I didn’t give the SSP2 much thought or investigation, and just assumed that it was a gate array or something. On inspection, the pin-out resembles a Renesas embedded DSP processor with analog inputs and outputs, digital I/O, USB and all of the usual suspects. The SSP2 in the S950 has 2MBytes of NOR flash program ROM (organized 1Mx16bits) and 2MBytes of SDRAM (organized 1Mx16bits). The clock crystal is a leisurely 12.2884MHz although the SDRAM read clock is 84.7872MHz.

Mysteriously, a web search on the part numbers doesn’t turn up much information. The part numbers are:

    Schematic ID  Manufacturer?       Yamaha
    ------------  ------------------  --------
    SSP1          MB87S1280YHE        X6363A00
    SSP2          UPD800500F1-011-KN  YC706A0

The PSR-S950 parts list does not give a Yamaha order number for the SSP2. If the SSP2 fails, you’ll need to call Yamaha 24×7 directly.

A web search does turn up a few of the interesting places where the SSP has been seen. In addition to Tyros 4, Tyros 5 and S950, the SSP and SSP2 are featured in:

    PSR-S500 arranger (probable role: effects processor)
    EMX5016CF mixer (role: SPX effects and user interface)
    Steinberg UR22 audio interface
    Steinberg MR816 Firewire audio interface
    Yamaha THR modeling guitar amplifier

The SSP is Yamaha’s designated hitter when they need an odd bit of DSP work done.

PSR-S770 and S970 internal architecture

Yamaha just recently introduced the new PSR-S770 and PSR-S970 arranger workstations. As usual, I’m always anxious to dive into the service manual and see what’s up.

First, I’d like to thank Uli and capriz68 on the PSR Tutorial Forum for their help. Uli made a very nice table from my ramblings, so be sure to check it out there.

Without further introduction, here is a table comparing previous generation models (PSR-S750 and PSR-S950) against the new models.

                    PSR-S750  PSR-S950   PSR-S770  PSR-S970
                    --------  ---------  --------  ---------
Main CPU            SWX08     SH7731     SH7731    SH7731
Clock rate (MHz)    135.4752  256        320       320
Tone generator      SWP51L    SWP51L     SWP70     SWP70
Ext clock (MHz)     11.2896   11.2896    22.5792   22.5792
DSP SDRAM (MBytes)  8         8          8         8
DSP RCLK (MHz)      45.1584   45.1584    95.9616   95.9616
Mic ADC                       AK5381     PCM1803   AK5357
AUX IN ADC          AK5357    AK5381     AK5357    AK5381
DAC                 AK4396    AK4396     AK4396    AK4396
Digital amp         YDA164C   2*YDA164C  YDA164C   2*YDA164C
Wave ROM (MBytes)   256       256        512       2048
Wave SDRAM          N/A       N/A        32MBytes  32MBytes
SSP2 chip           No        Yes        No        No

The main CPU remains a Renasas SH4AL-DSP CPU. The clock speed is increased from 256MHz to the 320MHz, which is just shy of the rated maximum for the SH7731.

Wave memory is increased from 256MBytes (S950) to 512MBytes (S770) and 2GBytes (S970). Part of the S770 and S970 wave memory is reserved for expansion pack voices: 160 MBytes (S770) and 512 MBytes (S950). How Yamaha uses the rest of the memory is up to Yamaha. However, we are now in an era when we cannot compare products solely on the basis of physical wave memory size. Our ears and performance experience are more important than mere byte counts!

The S970 has two NAND flash memory devices labelled “audio style.” The devices are:

    4Gbit NAND flash = 512MBytes
    2GBit NAND flash = 256MBytes
                       ---------
    Total audio style  768MBytes

Yamaha specifies memory size in bits, so one must be careful to convert during analysis. The PSR-S950 has a NAND flash device labelled “Program ROM,” which presumably served the same purpose as well as holding the operating system image that is loaded at boot time. The S950 device capacity is 512MBytes (4Gbits). The S970 reserves 128MBytes for audio style expansion.

The upper mid-range model, i.e., the S970, is biamplified with two digital power amps. The older S950 is also biamplified. Not much change here.

The big news is that Yamaha have a new tone generator integrated circuit (IC), the SWP70. The SWP70 uses the serialized wave memory interface that I described in an earlier post. The SWP70 appears to operate at twice the speed of the older SWP51L. The SWP70 has implications for other future products, so I will analyze it in a separate post.

With respect to the PSR-S970, however, there is another evolutionary step. With the appearance of the new SWP70, there is also the disappearance of the SSP2 IC. The introduction of the SSP2 IC coincided with the introduction of Vocal Harmony 2 in both the Tyros line and the PSR-S950. It is reasonable to infer, then, that vocal harmony is implemented on board SSP2. With the PSR-S970, there are two possibilites.

  1. Vocal harmony is assigned to the now faster main CPU, or
  2. SSP2 functionality is integrated into the new SWP70.

The SWP70 is beefed up in other ways including a new wave working memory.

The future looks interesting as always!

Here are links to my articles on other members of the PSR and Tyros product families:
What’s inside of a Yamaha arranger?
A follow-up on the Yamaha SWP51
Yamaha arranger product family

All site content is Copyright © Paul J. Drongowski unless otherwise noted.

Sending performance data via audio

It’s a challenge to get one’s head around the recent patents filed and obtained by Yamaha. In this post, I concentrate on one kind of communication technology that pops up in several patents.

Most people would like to get rid of the cables in their studio or living room. Radio-based communication technology like wi-fi (e.g. IEEE 802.11), Bluetooth, or Bluetooth Low Energy (BLE) seems like a no brainer for wireless communication. Radio is a bit of a regulatory nightmare for a global electronics corporation, however, because radio gear needs type acceptance and approval from governmental authorities. On a functional level, both wi-fi and Bluetooth communications are subject to interference, conflict and latency.

If Yamaha knows anything, it knows about latency and how latency can adversely affect the generation/transmission of data and sound.

US Patent 8,779,267 describes an approach to CDMA-like (code division multiple access) communication via near-ultrasonic sound (18KHz). Pseudo-random spreading codes allow multiple transmitters to operate within the same frequency band. Thus, multiple musical devices in your living room or studio can communicate with each other at the same time. The sound of ongoing communication — “control tones” in the terminology of the patent — are sufficiently high as to be inaudible to humans. (I wonder what dogs will hear and think? Seriously.)

The patent deals specifically with the modulation and generation of control tones by a synthesizer. The synth CPU borrows one of 32 tone generator channels to generate the control tones to be transmitted. The waveforms for the tones are stored, ta-da!, in wave ROM. Amplitude is constant (no ADSR for you) and the tone is sent only through the left channel to avoid sonic interference with itself through the right channel (avoiding phase cancellation, no doubt).

All in all, this is quite clever. Using a tone generation channel keeps cost low — no specialized modulator. The symbol rate is about 400.9 symbols per second, so transmission speed is not blazing fast. However, the ultra-sonic approach avoids the regulatory hassles and latency of consumer data radio technology.

The application discussed in the patent is the synchronization or display of “musical score data” on a tablet. The synthesizer sends control tones to the tablet telling notation software where it is in a musical score. The low symbol rate should be OK for this kind of application. If you’re curious about this application, then check out US Patent 9,029,676 (“Musical score device that identifies and displays a musical score from emitted sound and a method thereof”).

Six futher “embodiments” of theses idea are described in US Patent 9,006,551. The object of this invention is a musical performance information output device and system which superimposes musical performance-related information (e.g., notes, tempo, expression, etc.) on an analog audio signal without damaging the “general versatility” of the the audio data. The embodiments include:

  • A guitar that derives MIDI messages from string sensors and imposes the MIDI data on the audio signal.
  • A guitar that determines fingering information and sends it.
  • An electronic piano that sends tempo clock by imposing it on the audio.
  • A guitar that controls an effect unit.

And so forth.

Data is superimposed onto an audio signal. The signal can be sent in either free-air (patent ‘267) or over an audio cable (patent ‘551). There are probably limits and restrictions on free-air transmission such as signal strength, interference from ambient noise and so forth. Patent ‘267 assumes that the tablet and keyboard are in close proximity (speaker to microphone). In the case of ‘551, combining audio and data communication over an audio cable at least eliminates the need for a separate parallel data cable.

The normal disclaimers apply: Who knows if this technology will make it into product, how, or when?