Now (mostly) retired, I'm pursing electronics and computing just for the fun of it! I'm a computer scientist and engineer who has worked for AMD, Hewlett Packard and Siemens. I also taught hardware and software development at Case Western Reserve University, Tufts University and Princeton. Hopefully, you will find the information on this site to be helpful. Educators and students are particularly welcome!
Spot product shortages have sparked speculation about discontinued products, new products, etc. Given the human propensity to look for and find patterns, it’s no wonder that conspiracy theories take hold!
The on-line inventory picture is mixed. Some retailers show Yamaha Montage/MODX, for example, in stock, some show them out of stock pending September availability and, in one case, discontinued.
Random “discontinued” tags seem to come and go. A month ago, the Yamaha Canada site marked the MX as discontinued. Now the marker is gone. Better indicators are blow-out pricing to move stock or a Yamaha spiff incentive to move old stock. So far, I haven’t seen any clearance pricing or promotions.
Yamaha’s mid- to upper-end keyboard products have a vulnerable supply dependency on Asahi Kasei Microdevices (AKM) DACs and ADCs. The AKM factory fire was worse than originally thought and production is still not back on-line. Renesas has offered to manufacture AKM devices. The Yamaha UK site has the disclaimer, “Due to the difficulty in procuring semiconductors and procuring parts worldwide, some of our product area deliveries may be delayed. Thank you for your understanding.”
AKM aren’t very public about their recovery and certainly haven’t released a public roadmap. A recent press release for VELVET SOUND DACs and ADCs mentions sampling (no pun intended) in January 2022 with “mass production scheduled for the third quarter of 2022.” Given that Toyota is a top AKM customer, who wins, Toyota or Yamaha? 😉
The AKM shortage inspires other conspiracy theories, too. Theory #1: Yamaha are using non-AKM DACs and ADCs in Montage — the analog/jack (AJK) board was redesigned or manufactured with inferior non-AKM devices. Theory #2: MODX is suspended in order to give preference to and ship the wider-margin Montage. Someone went so far as to ask about replacement DACs in Montage and got the usual non-response from Yamaha. (What did they expect?)
Some of the Yamaha boards use Yamaha proprietary ICs, e.g., SWL, SWX, or SSP2 processors, creating a different supply dependency. When production inventory is exhausted, Yamaha need to re-spin end product to use a newer part. The July 2016 MX refresh is one interesting example. I believe that was the case with the MX refresh.
I haven’t seen a new version of the heavy weight SWP70 tone generator. However, Yamaha have updated both the SWX and SSP lines:
The SWX08 is replaced by the SWX09.
The SSP3 — now appearing in Steinberg and Yamaha pro audio products — will likely replace the SSP2.
Are new product spins in the works? Something is coming (eventually) given the CK61™/CK88™ and AN-X™ trademarks. Once again, only Yamaha really knows. 🙂
Yamaha Genos and PSR-SX900 arranger workstations have a feature called “Chord Looper”. Chord Looper records your left hand chords and saves them in a memory slot. (8 slots per Chord Looper bank.) Once recorded and saved, you can play back the chord progression and play over the changes. Neat.
Obviously, one way to enter a chord progression is to play it in. Let’s say, that the chord progression is long and has jazz chords like the Coltrane changes (AKA “Giant Steps”). These changes are notoriously difficult to solo over because the changes come fast, furious, and in three different scales! On top of musical difficulty, Chord Looper does not allow edits. Make a mistake and you need to record the entire sequence over again. So, folks are looking for ways to create and edit Chord Looper progressions.
Chord Looper CLD files
Fortunately, Chord Looper let’s you import and export individual chord progressions (i.e., a slot). Chord Looper exports a progression into a file with the CLD extension. Henceforth, I will call these files “CLD files”.
A CLD file is actually a Type 0 Standard MIDI File (SMF) in disguise. You can examine (or possibly edit/create) a CLD file by renaming the extension to “MID”. Once renamed, conventional software tools (Cubase, SONAR, etc.) will recognize the renamed CLD file as a Type 0 SMF and import it.
A CLD file recorded by Chord Looper is very simple inside. It contains a sequence of Yamaha XF chord events, one event for each chord change. Here are the metadata events for a simple progression (C-Am-F-G) played in by hand:
Chord Symbol 1.1.1.0 Metadata Chord: C/C Chord Symbol 1.4.4.112 Metadata Chord: Am/A Chord Symbol 3.1.1.34 Metadata Chord: F/F Chord Symbol 4.1.1.40 Metadata Chord: G/G
Each event specifies the chord root, chord type and alternate root bass. That’s it! A CLD file does not contain any other kind of event (notes, controller, time signature, tempo, etc.)
Each chord is a Yamaha XF Metadata chord event. The event time is the time of the chord event, i.e., when the player changed the chord and Genos recognized the chord. In the example above, the chord was changed at the beginning of each measure (sometimes a little early, sometimes a little late).
Chord STEP EDIT to CLD
Folks on the PSR Tutorial Forum have found a few ways of creating CLD files using existing software tools. Flip over to the forums and check out some of the Chord Looper threads.
Here’s a new method!
Yamaha arrangers have long supported a basic MIDI sequencer and editor. Like many software editors, the Yamaha sequencer supports step edit, letting you enter notes, control events, etc. with precise timing. One better, the Yamaha sequencer supports Chord STEP EDIT through which one can easily enter a chord sequence from a lead sheet into a separate chord track.
Thus, it’s possible to enter a chord progression easily using STEP EDIT and save the progression in a Type 0 Standard MIDI File. Initially, the progression is stored in a special part (Cds chunk) within the SMF. DAWs and so forth ignore the special proprietary data and typically delete it when writing the file back to MIDI. This kind of Chord STEP EDIT data does not contain the Yamaha XF chord events needed by Chord Looper. If you import one of these files into Chord Looper, Chord Looper comes up empty.
Once you EXPAND the step edit chord sequence, however, the expansion process creates Yamaha XF chord metadata events along with the notes and other MIDI events for the accompaniment parts. That’s the normal compositional process anyway — step edit the chord part, expand the chord part using the selected style, and save the expanded file as a Standard MIDI File.
One fly in the ointment. The Yamaha arranger software hides file extensions. This streamlines user workflow, but it inhibits interesting experiments! So, save the expanded MIDI file to a USB flash drive, take the flash drive to a personal computer, and rename the expanded SMF. Replace the “MID” extension with “CLD”. Copy the CLD file to the flash drive and reinsert the flash drive in the arranger workstation.
Import the newly renamed CLD file into Chord Looper. Voila! Chord Looper scans the file and produces a chord progression using the embedded Yamaha XF chord events. If you export the progression as a different CLD file, the exported data includes all of the other MIDI data, e.g., notes, etc. [I wouldn’t count on Chord Looper always doing this; software subject to change by Yamaha.)
Bottom line: If you pine to create and edit Chord Looper progressions with precision, use Chord STEP EDIT to create the progression, expand the backing, save as a Standard MIDI File, replace the file extension with CLD, and import into Chord Looper. Of course, you need to rename the MID file to a CLD file using a personal computer, but that’s a small hassle. Give it a try!
I tested this procedure on Genos with the Coltrane changes. Once the progression was captured in Chord Looper, I could try different tempos and different styles. Those changes do come fast and furious indeed!
overall Speculation about future Yamaha product reminded me of some unfinished business — analyzing the design of the Yamaha YC stage organ series.
Design of the YC series put some of Yamaha’s best minds to work including Dr. Toshifumi Kunimoto. “Dr. K” and his team are well-known for Virtual Circuit Modeling (VCM) and physical modeling (VL). Before reading ahead, it’s worth reviewing my post summarizing YC61 Developers’ comments. The article has link to a (subtitled) interview with Dr. K, Takashi Mori and Akinobu Shibuya. One big take-away is how the developers took a system-wide approach to emulation the Hammond sound.
The YC61 Owner’s Manual cites six specific innovations:
Natural, organic harmonies when playing chords — thanks to a matrix circuit that connects the keyboard, tone wheels, and drawbars.
Percussion sound with presence — based on vacuum tube circuit analysis.
Key clicks and leakage sounds — based on electrical circuit analysis.
Vibrato/Chorus effect — from scanner-based vibrato circuitry.
Changes in frequency characteristics and drive amount that responds dynamically to operation of the expression pedal.
These innovations are all in the realm of VCM and are needed to re-create the overall Hammond sound.
I assumed that Yamaha modeled the tonewheels, too. Now, I’m not so sure. I think the tonewheel waveforms are sampled and a modified form of AWM2 synthesis generates the basic, uneffected tonewheel signal (in digital form, of course). Here is my justification.
The interview and YC-series documentation
Yamaha are always honest about what they say even if they don’t say everything. Neither the developers’ interview or Yamaha documentation mention modeled tonewheels.
The YC specifications provide an important clue. Yamaha specify YC polyphony as:
VCM Organ + AWM2: 128 (Total of VCM Organ and AWM2), FM: 128
YC series keyboards have a single SWP70 tone generator (TG) integrated circuit (IC). Like the MODX design, the YC splits AWM2 and FM-X tone generation duties. It’s clear from the polyphony spec that the “VCM Organ” and AWM2 voices split resources, i.e., the AWM2 tone generation channels.
In AWM2 synthesis, each active voice element is assigned to an SWP70 tone generation channel. Genos and the upper-end PSR — also AWM2- and SWP70-based — assign a single drawbar waveform to an element (so-called “Organ Flutes” mode). Organ emulation on MODX (Montage) is similar.
Clearly, the AWM2 pipeline is involved in “VCM Organ” synthesis in some way.
Oh, the complexity!
Everyone is familiar with the 100,000 foot view of the Hammond tonewheel generator. A synchronous motor drives an assembly which spins the tonewheels. Each tonewheel has a pick-up that produces a fluctuating sine-like waveform. The waveforms pass through a key switching matrix and drawbars producing a mixed-down, composite organ tone. The tone is sent to the vibrato scanner, reverb, Leslie speaker, etc.
When it comes to modeling, the devil is in the details. I highly recommend reading one of the excellent Hammond tonewheel deep-dives on the Web:
When reading, please think about what is would take to write a mathematical model of this wonderful electro-mechanical contraption! It ain’t as trivial as summing up a bunch of sine waves. 🙂
The tonewheel assembly itself is closer to Charles Babbage’s mechanical Analytical Engine, than it is to an electronic home organ. The twelve (24, really) fundamental pitches are determined by integer gear ratios which approximate equal temperment. The tone wheels themselves have 2, 4, 8, 16, 32, 64, 128, 192 notches, producing subpitches at (near) octave intervals, derived from the fundamental scale pitches.
We know from our own experience that other aspects of the Hammond and Leslie organ system affect the final sound more than the basic tonewheel tones. If I were a developer, I would say, “Memory is cheap,” sample the tonewheels, move on and concentrate on the scanner, vacuum tube distortion, rotary speaker, etc.
Patents
Except, there is the issue of phase relationships when samples are played back. The Hammond tonewheel generator is a mechanical system with fixed relationships between tonewheel positions. This must be taken into account. Naive sample playback moves phase all over the place in an un-Hammond-like manner. Sample playback should be positionally aligned to preserve the fixed relationships present in a real, physical Hammond tonewheel generator.
Dr. K refers to “phase interference:”
“While collecting a range of different pitch waveforms, combining them, and including some non-linear additions, we also had to deal with phase interference between them. It turns out that this interference is not constant, and while balanced over the entire pitch of the instrument, the pitches do shift in subtle and inconsistent ways. … [T]his disordered yet harmonious behavior” is essential and necessary.
I believe that Yamaha have solved this problem by fetching and combining sampled tonewheel waveforms in a different way than everyday AWM2. Here are some patents to consider:
US Patent 10,388,290 B2 Multifunctional audio signal generation apparatus, August 20, 2019, Inventor: Taro Shirahama, Yamaha.
Japanese Patent 6360692 B2, Audio signal generation apparatus, July 4, 2018.
Yamaha could be aligning tonewheel waveforms when samples are fetched, thereby eliminating phase errors with respect to Hammond behavior. The sampled waveforms, of course, must also preserve the near-equal temperment of integer Hammond gear ratios. The end result is “Natural, organic harmonies when playing chords.”
I also want to draw attention to:
European patent application 20214572.8, Rotary speaker emulation — Device, musical instrument, method and program, December 16, 2020, Inventors: Yuji YAMADA and Takashi MORI, Yamaha.
This patent may summarizes Yamaha’s most recent work on rotary speaker emulation although the patent seems to be written as to obfuscate its intent. Yamaha has covered this territory before including:
Like “CK61â„¢” and “CK88â„¢”, the primary class is “Musical Instruments” and the trademark registration is “intended to cover the categories of musical instruments, namely, electronic musical keyboards, electronic pianos, music synthesizers.”
Although Yamaha submitted a drawing (below), the “mark is presented in standard character format without claim to any particular font style, size or color.” So, keep your fingers offa those characters! 🙂
Yamaha trademark application pending
Update: Yamaha have filed for a stylized (figurative) trademark in the European Union. See image below.
Of course, everyone is deconstructing the proposed mark. “AN” is known as Yamaha’s Analog Physical Modeling Synthesis as embodied in products like the AN200 Desktop Control Synthesizer. I’ve still got my AN200 and it’s a keeper. The AN200 consists of an SWX00B host processor and a PLG150-AN daugherboard. The PLG150-AN itself has a Renesas H8/300H 16-bit microcontroller and two Yamaha custom integrated circuits: VOP3 and MDSP. The custom circuits implement the VA synthesis and digital effects.
Yamaha AN200 analog physical modeling synthesis
It’s worth mentioning that VOP3 appears in the Yamaha FS1r — the inspiration for today’s FM-X. The FS1r does both 8-op FM and Formant Shaping Synthesis. Internally, two custom FS1-AB integrated circuits perform FM and formant shaping synthesis. Two VOP3 integrated circuits implement the filters (the first VOP3) and effects (the second VOP3).
Yep, I’ve mused about adding VA synthesis to Montage before and was skeptical about adding it to the existing SWP70-based Montage pipeline. I remain doubtful about adding VA synthesis to the existing Montage/MODX platform.
It’s worth noting, again, that Yamaha have never published nor described the actual data processing pipeline and signal paths within the SWP70 tone generator. I don’t have any formal relationship with Yamaha nor does Yamaha engineering ring me up regarding the internal details of their tone generation hardware. 😉 Do I have a right to change my mind in light of new information and analysis? Yes. Do I hope for a surprise from Yamaha? Yes.
The question is whether the SWP70 is capable of subsuming VOP3-like DSP functionality for VA synthesis. It’s how the YC series implements its Virtual Circuitry Modeling (VCM) organ engine. Clearly, if you can model drawbars, you can model an analog oscillator. Lest anyone forget, the Montage V3.0 upgrade (MODX V2.0) added the VCM Mini Filter, VCM Mini Booster and Wave Folder DSP effects.
As to filtering, what is a hardware or software digital filter other than a mathematical model of an analog filter — even if its cold and heartless? What is a digital amplitude envelope other than a model of an analog envelope generator and VCA? Distinction due to implementation technology is nearly moot; it comes down to the characteristics of the particular models.
What does all this portend for the future? If I were Yamaha and I could add VA to the Montage (MODX) platform, I would sell it as an upgrade. Many people want VA on Montage and there is money to be made.
I’m willing to go a step further. Yamaha could and should offer a VCM organ upgrade, too. The SWP70 can support it. I’ll put money where my mouth is — I will pay real money for a YC upgrade on MODX (Montage). BTW, there’s no technical reason to not offer the FM-based YC organs on MODX/Montage already — it’s FM-X, after all.
Oh, did I fail to mention, I added an Arturia Keylab Essential 49 to my iPad rig. I wanted a super light-weight MIDI controller with knobs, sliders, and a minimum of 49 keys with good action. The Keylab Essential 49 fits the bill at 6.6 pounds (3kg), eight pads, nine encoders and nine faders (sliders). The street price is attractive, too: $229 USD. I had a good experience with the Arturia Keystep 32 and decided to give the Keylab Essential a go.
Why the Keylab Essential after Korg Microkey Air joy? I gave the Air’s mini-keys the old college try and then some. First off, most mini-key instruments are three octaves and too short for two-fisted playing. The Microkey Air 49 has four octaves, making it much easier to play most tunes without finger gymnastics. [If you’re a pianist, we’re not even having this conversation!] Although the Microkey Air has Bluetooth MIDI built-in and is battery-powered — genuine plusses — it doesn’t have knobs/sliders for VST control. And, well, it still has those mini-keys.
Arturia Keylab Essential 61
The Keylab Essential 49 is only three inches longer than the Microkey Air: 30.9″ versus 27.9″. Sure, the Keylab Essential is twice as deep, but them encoders and 30mm faders have to go somewhere! I will admit, the Keylab Essential is not a “lap board” like the Air; it needs a proper stand and power source.
The Keylab Essential key action is decent enough. Like the Keystep, it feels a bit soft. If you want a fast, crisp action, this isn’t the droid you’re looking for. Even though the Keylab Essentials are Arturia’s budget line, the encoders and faders feel sturdy with a reasonable amount of resistance.
I’m happy with the Keylab Essential and, yes, I’ll be keeping the Microkey Air, too. Here’s my short Keylab Essential wish list:
Battery power
Bluetooth MIDI
Expression input, not simply sustain (on/off)
Then again, the price would be higher and/or the build quality would be lower. No free lunch.
Analog Lab
I’m mainly interested in iPad (IK BX-3) and hardware (YC and Skulpt SE) control, not PC-based VSTs. However, Analog Lab is a fun leisure destination. Analog Lab and its integration with Keylab Essential are simply brilliant. Prepare to waste long hours jamming away with the best sounds of yester-year with lots of knob twisting and fader slamming.
Controlling Yamaha Reface YC
Yamaha Reface YC is one of my keeper keyboards. It’s been a handy companion at rehearsals and even a few church services. You’ve already heard my gripe about three octave mini-keyboards and Reface YC occupies that doghouse. No need to repeat.
Fortunately, Keylab Essential is almost made for Reface YC. [Dreamers, Yamaha has a full-size YC; forget a Reface re-issue.] Keylab Essential has a 5-pin MIDI OUT which links to the Reface YC dongle MIDI IN. Thank heavens for 5-pin MIDI.
Arturia provide their MIDI Control Center (MCC) app for configuration. The Keylab Essential has eight configuration slots: Analog Lab, DAW and six user slots. MCC communicates with Keylab Essential over USB. Fortunately, the 5-pin MIDI OUT operates concurrently with a USB connection back — no either/or.
Obviously, the faders map to the YC drawbars. Fortunately, the Keylab Essential faders have a drawbar mode, flipping low and high values. The Reface YC drawbars are controlled by MIDI continuous controller (CC) messages CC#102 to CC#110. It’s all right there in the Reface Data List PDF available on the Yamaha Web site.
Amazing how many people will ask a forum for such info. Please RTFM.
The rest of the front panel controls — waveform, rotary speed, vibrato/chorus, percussion, and effects — are under MIDI CC control, too. Keylab Essential has three switches (Part 1, Part 2, Live) which are mapped in the following way:
Vibrato/chorus select (CC#79)
Percussion on/off (CC#77)
Percussion harmonic (CC#112)
The switches are configured as toggles, so that the switch LEDs indicate individual switch state.
Rotary speed is interesting because Reface YC has four states: OFF, STOP, SLOW and FAST. By default, Reface YC modulation (CC#0) switches between SLOW and FAST. As an alternative to the wheel, I assigned OFF, STOP, SLOW and FAST to pads 5 through 8. It’s a shame that Keylab Essential doesn’t support radio buttons. If it did, one could make each pad in the group a toggle showing the current rotary speed state.
As I mentioned, Keylab Essential does not have an expression pedal input. Thus, I route a Yamaha FC-7 expression pedal to Reface YC directly. The Keylab Essential sustain input is still useful, however. I attach a sustain pedal and assign the sustain input to rotary speed (CC#19: SLOW and FAST). Momentary switch mode allows quick changes and speed bumps.
It’s worth noting here that rotary speed has four settings:
CC#19 Value ---------- ----- 0 - OFF 0 1 - STOP 42 2 - SLOW 85 3 - FAST 127
Switching between SLOW and FAST means changing CC#19 between 85 and 127.
Making the rest of the story short, the remaining Reface YC parameters are assigned to the encoders. Waveform, vibrato/chorus depth and percussion length have five discrete settings each, i.e., they do not sweep continuously across 1 to 127. Expect to hear discrete changes (steps). The step values are: 0, 32, 64, 95, 127.
Vibrato/chorus does not have a Reface on/off switch. Vibrato or chorus are OFF when the vibrato/chorus depth is zero.
Here is a table which summarizes the control mappings:
-------------------------------- ---------------------------------------- Reface YC Arturia Essential 49 -------------------------------- ---------------------------------------- Rotary speed 19 0-127 Mod wheel, Pad 5-8 OFF, STOP, SLOW, FAST Wave 80 0-127 Knob 1
Arranger forums are anticipating a new Korg flagship arranger, the Korg Pa5x, on 30 June 2022. Sud Claviers France have taken the lead for European introductions before, as arranger keyboards are more popular in Europe and Asia than North America. Various Korg (and Yamaha!) forums have leaked images and video — a lot of it blurry. Fans are usually good at spotting fakes, but this time it looks to be real.
You’ll pay a high price for the Pa5x jewelry. The Roland E-X50 is for punters having an estimated $400 USD price. (The Pa5x will cost 10x that amount.)
Roland E-X50 arranger keyboard
The E-X50 has a sleek, professional, squarish look to it, weighing 9.6kg (21.3 pounds). The new arranger kits out with 256 polyphony, 433 regular tones plus 256 GM2 tones and a total of 18 drum sets. Effects include equalization, chorus, reverb and delay. The stereo audio system is 10 Watts per side through a 12cm speaker and 3cm tweeter. With a 30 Watt power draw, it’s an AC adaptor; no battery power.
Bluetooth is built-in. The E-X50 has fixed formet LCD display which is typical for entry-level keyboards.
Auto-accompaniment and registration memory are on par with Yamaha, Casio, and Korg. Roland have not broken any new ground, here. The most novel feature is AUDIO PAD playback. The Scale Tune buttons are linked to WAV (or MP3) files on a USB drive. Striking one of the buttons plays back the associated audio file (one shot or loop). Unlike Yamaha arrangers which are notoriously picky about audio file format (16-bit, 44kHz stereo), the E-X50 supports a broad range of bit rates and sampling frequencies. (You’re still stuck with 16-bit samples, tho’.)
The E-X50 is supported by a free E-X Style Converter application (Windows and Macintosh), which converts a MIDI file to a style file compatible with the Roland E-X series.
Bottom line, the E-X50 offers an alternative to similar units from Korg and Yamaha. Every vendor has its own sound and this Roland may float your boat more so than Korg or Yamaha.
Moog Mavis is a new build-it-yourself monophonic analog synth kit from Moog. I rather like the looks of Mavis right off the top. The front panel screams “Moog”. It has a mess o’patch points (24-point CV controllable) on the left hand side of the front panel. The module is 44HP in case you want to rack it up. The Mavis form factor is compatible with earlier units like the DFAM.
Moog Mavis monophonic analog synth module
Mavis boasts the Moog “legendary oscillator and filter circuits,” adding a diode wave folder. The filter spec is -24 dB Moog Low Pass Ladder filter. Mavis has a built-in courtesy keyboard. Serious folk will be driving Mavis from external, 1 V/oct gear.
“Build-it-yourself” is more like assemble it yourself as the mainboard is fully wave soldered, etc. No soldering required.
Mavis is $349 USD. That seems a little price-y, but you get an entire monophonic synth signal chain. Near as I can tell, Mavis avoids the shortcomings of the Werkstatt-01. I almost bit on a Werkstatt-01 until I realized its interfacing limitations. And guess what? Mavis is already in stock at a few on-line retailers! Nice work, Moog.
I want to give a shout out to Lionel on the PSR Tutorial Forum. He posted a very nice PSS-A50 mod — stereo!
Yep, the PSS-A50 is stereo and, as Lionel discovered, the in-built samples are also stereo. Check out Lionel’s PSS-A50 stereo mod video. His video begins with a great close-up of his changes to the PSS-A50 digital main board (DM).
As noted in my PSS-A50 look inside, the central computer and tone generator is Yamaha’s SWLL processor (YMW830-V). The SWLL is a system-on-a-chip (SOC) which integrates the host CPU, working memory, key/display scanner, and tone generator. Just add a 37-key keyboard, display driver, 2MByte serial flash program/waveform ROM, USB controller, audio electronics and power electronics, and you have a complete ultra-low cost synthesizer.
The digital-to-audio converters (DAC) are integrated into the SWLL. The SWLL has six DAC-related pins:
DACLPP (pin 1)
DACLMM (pin 2)
DAC_VDD (pin 3)
DAC_VSS (pin 4)
DACRMM (pin 5)
DACRPP (pin 6)
DAC_VDD and DAC_VSS are conversion reference voltages. DAC_VDD is derived from DAC_VCC produced by a low drop-out voltage regulator (Texas Instruments TLV74333PDBVR). DAC_VSS is ground.
Yamaha SWLL (YMW830) DAC signals
DACLPP and DACLMM are differential audio signals for the left channel. DACRPP and DACRMM are differential audio signals for the right channel. DACRPP and DACRMM are left unconnected in the PSS-A50. There are two test points, DACL- and DACL+, on the printed circuit board (PCB), in case you would like to probe these signals.
PSS-A50 post-DAC low pass filters
DACL+ and DACL- feed two operational amplifiers which are low pass filters. The low pass filters produce signals LOUT+ and LOUT-, which are sent to the plus and minus inputs of the headphone amplifier (TPA6132A2RTER) and speaker power amplifier (Rohm BD27400GUL). It’s differential audio signals all the way, presumably, to keep noise low.
The Texas Instruments TPA6132A2RTER is a 25 mW stereo headphone amplifier. The Rohm BD27400GUL is a low voltage class-D monaural speaker amplifier.
I have to admire Lionel’s construction skills as it is quite difficult to solder wires to a surface mount IC. Nice work replicating the stereo low pass filters, too.
Keep the Yamaha PSS-A50 hacks coming! Please don’t forget the PSS-A50 MIDI mod.
Here are some additional Yamaha PSS-related stories:
Update: If you’re looking for information about the new Yamaha CK61 and CK88, see my specification and snap review articles.
With NAMM 2022 coming up (June 3-5), it’s time for rumors. 🙂
Yamaha filed for two new trademarks in June 2021. The trademarks are words in stylized form. The scope is “Musical instruments, namely, electronic musical keyboards, electronic organs, electronic music synthesizers, cases for musical instruments”.
Trademarks applied for and published soliciting opposition
The main marks are CK61â„¢ and CK88â„¢. The marks:
CK SIXTY ONE; CK SIX ONE; CK 61
CK EIGHTY EIGHT; CK EIGHT EIGHT; CK 88
are alternative forms.
The marks have been published, soliciting opposition as of 29 March 2022. Seems reasonable that a manufacturer would want the product identifier approved before making a zillion units with the name stamped on.
Let the speculation begin! Clearly, 61-key and 88-key keyboards are involved. Duh! “C” for “control”? Somewhat reminiscent of the old control synth product range? No 76 model?
The font is similar to the Yamaha Reface series marks. I’d love to see a merged all-in-one Reface-like keyboard with full-size keys. The MX series is getting a little long-in-the-tooth, so its replacement might be another possibility? Hope the price is reasonable…
When Reface YC and CP grew up, Yamaha kept the stylized names and font in the names of the YC and CP stage keyboards. Maybe a new stage keyboard in the Yamaha synth product group? A combined FM and virtual analog keyboard that doesn’t overlap the YC and CP models?
Watching ADS-B “flight radar” has been cheap entertainment and a window into the larger world.
ADS-B, in case you didn’t know, is an alternative means for tracking aircraft. (“ADS-B” stands for “Automatic Dependent Surveillance-Broadcast”. Who came up with that acronym?) Aircraft carry an ADS-B transmitter which broadcasts identification and positional information. Aircraft are identified by a 24-bit ICAO address and (optional) call sign. In the case of commercial aircraft, the call sign is typically the airline and flight number. Position is determined by on-board GPS and altimeter data. So, the aircraft is telling ADS-B receivers where it is.
ADS-B data links operate at 1090MHz or 978MHz. 978MHz frequency reduces message congestion on 1090MHz. ADS-B on 1090 is essentially a modified Mode S transponder.
Since ADS-B operates on such high (UHF) frequencies, it is a line-of-sight system. If you have an ADS-B receiver, it will receive only aircraft in sight of the antenna (assuming sufficient signal strength). Because all ADS-B reception is local, web sites like Flight Radar 24 and ADS-B Exchange aggregate ADS-B data from receivers around the world and display current data on a map. That’s how they create the illusion of being global.
The airspace in eastern Europe has been especially interesting. The Ukraine war zone is dark as one might expect for contested — and dangerous — airspace. Occasionally you will see an aircraft fly into Ukraine and immediately kill it’s ADS-B transmission. Conversely, a pilot forgets to turn off ADS-B and you might spot a fighter near the border! Other popular aircraft for trackers include NATO AWACS, drones, tankers and cargo planes.
Let’s say you want to track aircraft in your own nearby airspace. If you have a software-defined radio (SDR) receiver, you’re most of the way there. I have successfully tracked flights in the northern Seattle area using both an RTL SDR Blog V3 radio and a nooelec Nano 2+ SDR. Comparing the two, the RTL SDR blog radio seems to have a wider range and is more responsive than the nooelec Nano 2+.
ADS-B at-home antennas
In addition to a receiver, you need an antenna. I used the bundled antennas which came with the receivers. The nooelec is a vertical whip antenna set to a 1090MHz full wave, 27.5cm. The RTL SDR antenna is a vertical dipole where each element is set to a half-wave. The difference in range may be due to the different antennas. Unfortunately, I don’t have the right coax adapters to mix and match. (Maybe after the next Amazon order.)
ADS-B radio signals are vertically polarized so get those antennas straight up and down!
Finally, the keyword in software-defined radio is “software.” You’ll need a program to tune the receiver, demodulate the ADS-B signal and display the ADS-B data (in either a table or on a map).
After seeing a positive review on the RTL SDR blog, I decided to try SDRangel on Windows 10. SDRangel has come a long way since I first took a look. SDRangel is set up differently than programs like AirSpy SDR# (SDR-sharp). To my point of view, SDR# and other programs like it are intended mainly for voice (audio) signal modes. They make great receivers for wide band FM, narrow band FM and AM. You’re on your own when it comes to digital modes like ADS-B. The SDR# signal processing chain is already set up like a radio and is pretty much ready to go after installation and launch.
ADS-B via SDRangel (north Puget Sound/Seattle area)
SDRangel, on the other hand, requires a little bit of knowledge about the processing signal chain. First you create a workspace to hold the signal chain. Then you create a receiver to tune in a signal. Finally, you create one or more “channels” where each channel is a demodulator. SDRangel provides a wide range of demodulators (plug-ins), one of which is ADS-B.
I recommend trying an audio mode first, just to learn your way around SDRangel. I tuned in a local National Weather Service (NWS) station on 162.55MHz narrow band FM (NBFM) using the NBFM demodulator (plug-in). The NWS station is 24/7 and is fairly strong. None the less, I needed to raise the RF gain and turn off the squelch in order to hear anything. Not the same “out of the box” experience as SDR#.
Once set up, though, turning to ADS-B was a snap. I created a new workspace and put a receiver (tuned to 1090MHz) and ADS-B demodulator into it. I needed to increase the SDR sampling rate to 2,000,000 (hint: set the decimation factor to 1). If you don’t up the sampling rate, you’ll get a red warning message and no ADS-B data.
With this set-up, I can track flights in the north Puget Sound area. The antenna is indoors (house rules), but it will still see quite a few flights between the Sound to the west and the Cascade mountains to the east. I compared the SDRangel output with Flight Radar 24 and was satisfied. Because I was receiving on 1090MHz only, I am missing flights on 978MHz. More experiments to do one day. 🙂
Casio’s pre-NAMM 2022 press release mentions a few art projects to be released and shown during NAMM 2022, June 3-5.
Music Tapestry creates pictures from musical performances — a modern day color organ, for you old-timers like me. Music Tapestry is triggered by musical pitches and keyboard touch. Casio Sound Developer Hiroko Okuda — who helped developed Music Tapestry — will demonstrate it at the Casio booth.
Black and white example from U.S. Patent 10,803,844
Casio’s U.S. Patent 10,803,844 (October 2020) discloses a process to visualize musical performance. Hiroko Okuda is one of the inventors.
If you think the Casio CT-S1 is too plain, try the “Flowers & Hearts” fabric by Brazilian pop artist Romero Britto. Casio will be selling a Limited Edition CT-S1 FH model (limited to 200 units at $500 USD).
Check out more of Britto’s work on-line!
Of course, Casio will be demonstrating their latest products including the Casio CT-S1000V with vocal synthesis. I’ll bet that the CT-S500 will be there, too. 🙂
