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? π
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 CK61β’/CK88β’ and AN-Xβ’ trademarks. Once again, only Yamaha really knows. π
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. π
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 “CK61β’” and “CK88β’”, 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! π
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. π 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.
Mid- to upper-level Yamaha arranger workstation have long had a drawbar organ feature which Yamaha calls “Organ Flutes.” This feature dates back to 1999, appearing in the PSR-9000 keyboard. Although a few details have changed over the years, Yamaha has not substantially overhauled Organ Flutes. It’s time, Yamaha — the world has moved on. I’d love to see the new YC organ technology in Genos. It’s the flagship of the arranger line and YC organs would definitely differentiate Genos from its lower-cost brethren.
Yamaha Organ Flutes main voice editing screen
The main, tweakable organ parameters are:
Nine drawbars
Percussion (first note/each note, length)
Percussion pitch (4′, 2-2/3′, 2′)
Response (onset delay of drawbar and percussion sounds)
Vibrato (on/off, depth, speed)
Rotary speaker speed (slow/fast)
Volume level (1 to 8)
DSP effect (e.g., rotary speaker)
For B-3’ers, the 4′ percussion pitch is the 2nd harmonic setting and the 2-2/3′ percussion pitch is the 3rd harmonic setting. The 2′ pitch supports non-Hammond organs which require it.
Compared with a contemporary clonewheel, one immediately notes a few missing features:
Vibrato only, no chorus
No key click
No rotor noise
No leakage
Overall, the Genos B-3 is super clean and polite — not vintage. MODX (Montage) provides key click, rotor noise (grit) and rotor whistle waveforms. Why does Genos lag behind? Although MODX is AWM2, not modeling, these extra waveforms are better than nothing at all.
The Genos synthesis engine is also AWM2 sample-playback and AWM2 provides the Organ Flutes vibrato. Organ Flutes does not simulate the one-of-a-kind Hammond vibrato/chorus scanner. The Korg Module “Gospel Organ” voice incorporates C-3 chorus and the AMW2 vibrato just doesn’t cut it (head-to-head comparison). I had to substitute Genos’ V-2 setting and move on.
Simplified, graphical rotary speaker interface
If you want to change the rotary speaker type, you need to dive through the effect setting button at the top of the Organ Flutes screen. After selecting the insertion effect, Genos displays a skeuomorphic (graphical) rotary speaker cabinet with a few knobs. In the screenshot above, we get rotary speed, horn and rotor balance, and microphone left/right angle. Like many (most?) rotary speaker simulations, the rotary effect emulates the sound of a mic’d up, stereo recording of a Leslie, not a horn and rotor moving air in a room.
Additional rotary speaker (DSP) parameters are changed by tapping the “Detail” button in the lower right corner. deep-diving reveals a few more deficiencies:
Missing parameters due to a limitation on the number of DSP effect parameters (16 parameters maximum)
Only one insert effect (typically the rotary speaker)
Volume control is post-effect and does not affect overdrive
Here is a little more information about each issue.
First page of rotary speaker parameters
At heart, the Genos (PSR, Tyros) sound engine implements the Yamaha XG synthesis and effects architecture. The XG architecture allows up to sixteen (!6) parameters per DSP effect unit. Unfortunately, Yamaha’s DSP engineers are creating effect algorithms (AKA “effect types”) with more than sixteen parameters! The MODX ROTARY SPEAKER 2 algorithm has eighteen (18) parameters. The Genos REAL ROTARY effect type is the same algorithm as MODX. However, only 16 parameters are accessible or stored on Genos. The two missing REAL ROTARY parameters are:
Slow-Fast Time of Rotor
Fast-Slow Time of Rotor
You cannot change these rotor ramp times on Genos, yet, you can change them on MODX.
This issues affects the Genos UNI COMP compressor algorithm (MODX: UNIVERSAL COMPRESSOR DOWN). Dare I mention the inability to specify a side-chain part, too? People are trying to create EDM on arrangers.
The XG architecture allows only one insert effect per part. The Organ Flutes insertion effect is typically a rotary speaker simulator. The MODX effect architecture, on the other hand, allows two insert effects per part. Yamaha synths take advantage of the second insert effect to add overdrive or vintage EQ:
Rotary speaker 1 β Multi FX (Distortion Solo)
Rotary speaker 2 β VCM 501 EQ (Flat)
Amp Simulator 3 (Tube) β VCM 501 (Flat)
Amp Simulator 1 (Stack 2) β Rotary Speaker 1
VCM 501 EQ (Flat) β Rotary Speaker 1
The rotary speaker drive alone is not enough to warm up the basic sound nor is it enough to get a sweet, realistic overdrive with guts. I experimented with the Genos REAL ROTARY effect and got some very squirelly results at high drive levels. The algorithm can be pushed in unexpected, undesirable ways while searching for true funk.
Unlike a real Hammond/Leslie combination, the Genos expression pedal controls post-effect part volume. This is like putting the volume control after the Leslie speaker. A Hammond B-3 pedal controls the level into the Leslie pre-amp. Thus, the pre-amp frequency characteristics and overdrive track the Hammond pedal. The Yamaha YC61 modeling gets this right. Putting the volume pedal before the pre-amp lets the player get clean or dirty in the same way a guitarist uses picking and/or the guitar volume knob to distort or clean up their tone.
If the Genos developers must work around the XG architecture, they should consider a new effect algorithm that combines overdrive with the rotary speaker simulation. The algorithm should allow foot pedal control over the Leslie pre-amp input level. Genos and other PSRs allow wah pedal control, so they obviously know how to achieve this capability within the current architecture.
Maybe it’s the first day of the regular NFL season or the phase of the moon. Here’s a recap of a few questions that came into the forums.
How are arranger/synth preset voices stored? First, one may ask, “How is a preset represented?” Typically, a preset voice consists of waveforms (AKA “samples”) and voice (meta-)data. The voice data control how the sample-playback engine applies filtering, amplitude envelope, modulation and so forth. The waveforms, of course, provide the basic digital audio data.
There is such a broad range of arranger/synth products at different price points, that the amount of storage and the kind of storage varies quite a lot.
The lowest of the low in the Yamaha range: PSS-A50, -E30, -F30, PSR-F51. Presets are stored on a 2MByte serial flash ROM and are loaded into the processor (SWLL) at start-up. The 2MBytes include code, too! Tone generation is integrated into the SWLL. Insanely small, and very low cost.
The highest of the high in the Yamaha range: Genos. Factory presets are stored in four 1GByte ONFI NAND flash devices. Expansion memory consists of two 1GByte ONFI NAND flash devices. Wave memory connects directly to external tone generators (SWP70).
I’ve looked at the diagrams for Genos and I’m not sure about the size and function of those memory units, especially Genos USER memory and expansion memory.
Yamaha confuses people when they speak of “user memory,” “internal memory,” etc. They are usually referring toΒ logical, user visible storage.
When getting down to the hardware level, there are many different physical memory units. since we’re not discussing fairy dust or magic, the logical storage must be assigned to one or more physical memory units. And, of course, the physical memory units themselves may be composed of multiple integrated circuits. The other dimension is “what communicates to what.” Memory is passive and needs a processor to initiate reads and writes and to do something with all that data. At the physical level, a memory unit essentially belongs to a single processing unit (host computer, tone generator) and directly communicate with it.
Sometimes I think of the SWP70 as a parallel processor just like a GPU. The CPU/SWP70 is not exactly analogous to host CPU plus GPU, however. Graphics memory is shared between CPU and GPU. The SWP70 does not share its waveform memory with anybody — it’s dedicated to the tone generator. That’s why installing an expansion pack (voice library) is kind of slow and technically complicated, and why a Genos reboot is required.
Yamaha Genos SWP70 tone generators
Staying with Genos, Genos has two SWP70 tone generators: one handles factory presets and the other handles user expansion voices. The factory SWP70 has 4GBytes of flash memory while the expansion flash memory has 1GB of flash memory. That’sΒ physicalΒ memory. Yamaha boosted the effective capacity to 3GB expansion through compression.
The SWP70s also have DSP RAM. As a user, you never know about this memory. It’s scratchpad memory for DSP effects. Physically, the DSP RAM is completely separate and independent from the waveform memory, and communicates with only its parent SWP70.
Yamaha Genos Host CPU
The host CPU has two kinds of memory (as determined by its bus interfaces): 1GB of working RAM on the CPU memory bus (EMIF) and two embedded eMMC memory devices that act like solid state storage drives (MMC0 and MMC1). As far as a user is concerned, the user never sees the 4GB eMMC drive (MMC0) just like you don’t see the DSP RAM; it’s hidden. The MMC0 drive contains the Linux operating system kernel and the root file system.
The user sees only part of the second 64GB eMMC drive (MMC1). The user sees theΒ logicalΒ storage which Yamaha calls “Internal memory” or “USER drive.” What’s in the remaining 6GB? I don’t know — Yamaha haven’t left any clues.
What about Montage and its 5.67GByte waveform memory? 5.67GB is the capacity when the waveforms (samples) are compressed. Again, this is logical storage capacity.
Yamaha Montage SWP70 tone generators
Montage has two SWP70s. One SWP70 is dedicated to FM-X and it does not have waveform memory. The second SWP70 handles AWM2 synthesis (sample playback) and has waveform memory connected to it. The waveform memory consists of four 1GByte devices totaling 4GBytes. Thanks to Yamaha’s proprietary compression, Montage stores 5.67GBytes-worth of data in the physical waveform memory. The remaining space, 1.75GB physical, is available for user samples.
How does sample capacity relate to price? It doesn’t. Component cost is outweighed by manufacturing costs, software development cost and sound design cost.
If the memory components are so cheap, why isn’t there more waveform memory? If there was more, then you wouldn’t buy the Mark II model, would you? π
I understand that E30/F30 do NOT offer velocity sensitivity. My question is about the internals. Is it confirmed that it’s a keybed with two switches per key, that just aren’t supported in software?
Yes, you need to be careful here. There are hardwareΒ model differences: E30 and F30 are not velocity sensitive. A50 is velocity sensitive.
There are two different keybed printed circuit boards (PCB). Yamaha part number VAY27800 for F30/E30 and VAY28500 for A50. The A50 PCB has the necessary diodes installed for velocity sense. The F30/E30 PCB does not have the diodes. Further, the A50 board has a 12-pin connector while the F30/E30 board has an 11-pin connector — perhaps to avoid assembly mistakes.
Yamaha Reface key switch matrix schematic
Is velocity sense worth the extra bucks? There may be other differences, too, but these differences are plainly visible.
And the usual caution/disclaimer — kiss the warranty good-bye! For the money, the PSS should be good mod-fodder. Korg probably sold a mess o’monotron that way.Β
The Motif XS/XF (MOX/MOXF) and Montage (MODX) arpeggios and performances are a great source of inspiration. Unlike Yamaha’s arranger series, the built-in phrase library is rich in urban and chill patterns. For some odd reason, one of the classic XS/MOX performances — “Dresden At Night” — never made the leap to Motif XF. And, it’s missing from Montage/MODX, too.
A PSR Tutorial forum member sought help resurrecting Dresden At Night, albeit a recreation for the PSR-SX700 arranger. I thought I would help out since I wrote a series of articles about MOX performance to style conversion:
If you would like to try Dresden At Night or experiment with a conversion of your own, download the free ZIP file.
MOX performances have four parts (voices). Each part has up to six musical phrases (arpeggios) associated with it. Six front-panel buttons select the currently playing set of arpeggios, i.e., button one selects the first arpeggio for each set and so forth. To get the basic MIDI data, I played each arpeggio (group) for four measures while recording in MOX performance quick record mode. I wrote out the MIDI data as a Standard MIDI File (SMF), transfered the SMF to PC, and imported the SMF into a DAW (Sonar).
Dresden At Night is a downtempo (91 BPM), urban-ish chill performance. It has four parts:
Part# Voice Name NoteLo NoteHi VelLo VelHi Level Pan ----- -------- ---------------- ------ ------ ----- ----- ----- --- 1 PRE8:070 8Z Heavy Hearts C-2 G8 1 127 81 C 2 PRE3:053 Dark Bass C-2 G8 1 127 51 C 3 PRE7:110 Ibiza Groove C-2 G8 1 127 127 C 4 PRE5:121 Smooth BPF Sweep C-2 G8 1 127 73 C
The first part is the rhythm voice and the second part is the bass voice. As we’ll see below, arpegiation is turned for these two parts. The third and fourth voices are a play-along pad layer and arpeggiation is disabled. Thus, the rhythm and bass parts provide a looped backing while the pad voices provide an atmospheric you-steer-it, right hand part.
Here are the arpeggio assignments:
Arp#1 Tempo:91 Arp#2 ----- ----- 1 MA_8Z HeavyHrt1 1 MA_8Z HeavyHrt3 ON 2 MB_WestCoastPop _XS 2 MA_WestCoastPop _XS ON 3 MA_Space Arp 3 MA_Space Arp OFF 4 MA_Up Oct1 4 MA_Up Oct2 OFF Arp#3 Arp#4 ----- ----- 1 MA_8Z HeavyHrt4 1 MA_8Z GatedBt3 ON 2 BA_Jazz Pop _XS 2 FB_WestCoastPop _XS ON 3 MA_Space Arp 3 MA_Space Arp OFF 4 MA_Up Oct4 4 MA_Down Oct1 OFF Arp#5 Arp#6 ----- ----- 1 MA_8Z ChillBrk4 1 BA_Sp SFX ON 2 MB_WestCoastPop _XS 2 MA_WestCoastPop _XS ON 3 MA_Space Arp 3 Off OFF 4 MA_Down Oct2 4 Off OFF
The Arpeggiator is turned ON for Parts 1 and 2 only.
A big factor is the “8Z Heavy Hearts” drum kit. The “8Z” in its name means “eight zone”. Eight zone (8Z) voices are a Motif innovation beginning with the XS (MOX) family. If you would like more information, check out these earlier posts about eight zone voices:
8Z voices aren’t drum kits. They are implemented as synth voices and are just a clever way of using the eight elements which make up a voice. The eight zones (8Z) are divided across specific note ranges. 8Z Heavy Hearts assigns waveforms (zone sounds) in the following way:
Yamaha messes with each of the zones in crazy ways and ties keyboard notes to voice parameters (AKA “key follow”). For 8Z Heavy Hearts, the most notable effect is how the Clap AnSm pitch follows the keyboard.
Arrangers (even Genos!) don’t have 8Z voices. They have standard drum kits where each MIDI note is a separate drum instrument. In order to make a PSR style using a DAW, one must translate the 8Z MIDI notes to standard drum kit notes. You need to assign appropriate drum kits (e.g., DrumMachine, Analog T9, House, Break or HipHop) to style parts 9 and 10 (MIDI channels 9 and 10) and copy the Heavy Hearts MIDI data to both Parts. Then, delete the notes that aren’t needed in a style part, compress each zone into a single drum instrument, and map the resulting “compressed” notes to the appropriate drum instrument(s). So, for example, all of the notes in C0 to F#0 might be compressed into the Kick T9 1 instrument (B0) in the Analog T9 Kit, which is one of the target drum kits.
I found two PSR drum parts to be enough. However, styles are flexible and you could assign a third (fourth, β¦) drum kit to one of the other style parts. There’s nothing in Yamaha styles that prevents this. It’s just that parts 9 and 10 (MIDI channels 9 and 10) are conventionally assigned to drum parts in a style.
I went with two PSR drum kits: Analog T9 kit and Drum Machine kit. Here is one possible assignment:
Note Low Note High Waveform Instrument Note# Kit -------- --------- ------------- ---------------- ------ ----------- C0 24 F#0 30 Bd T9-1 Kick T9 1 35 B0 AnalogT9Kit G0 31 C1 36 Bd Hard Long BD Hard Long 24 C0 DrumMachine C#1 37 D1 38 Sd Elec12 Snare Analog CR 63 D#3 DrumMachine D#1 39 F1 41 Sd HipHop6 Snare Hip 1 86 F#3 DrumMachine F#1 42 A1 45 HH Closed D&B Hi-Hat Closed Syn 91 A4 DrumMachine A#1 46 C2 48 HH Open T9 Hi-Hat Open T9 46 A#1 AnalogT9Kit C#2 49 C4 72 Clap AnSm Clap Analog Sm 27 D#0 AnalogT9Kit C#4 73 C6 96 Shaker Hip2 Analog Shaker 57 A2 DrumMachine
A lot of detail, huh? Nobody said style conversion was easy. π In the end, I spread each zone across multiple drum instruments of the same type, i.e., assigning the Shaker Hip2 zone to a few different Analog Shaker sounds in the Drum Machine kit. Part of 8Z Heavy Hearts’ charm is the subtle sonic variation provided by each zone.
Trying to keep this all straight in the DAW piano roll is cognitively challenging. Did I say, style conversion isn’t easy? π
Fortunately, one can loop four bar sections and play the MIDI through the arranger (Genos, in this case) just like a MIDI song. Then, it’s the usual tweak, listen, rinse, repeat edit process. When the MIDI is tweezed to your liking, you need to add MIDI markers to delimit the style sections. (BTW, leave a one bar MIDI set-up measure at the beginning.) Style section markers are:
Set-up measure 1: SFF1 Set-up measure 1: SInt Main sections: Main A, ... Fill sections: Fill In AA, ... Break section: Fill In BA, ... Introduction: Intro A, ... Ending: Ending A, ...
At a minimum, you need a few MIDI set-up System Exclusive (SysEx) messages at the beginning of the SMF (measure 1, beat 1):
F0 7E 7F 09 01 F7 GM Reset F0 43 10 4C 00 00 7E 00 F7 XG System ON F0 43 10 4C 02 01 00 01 16 F7 Reverb type F0 43 10 4C 02 01 20 16 00 F7 Chorus type
Reverb is the “Light Hall” preset and chorus is the “Tempo Cross 1” preset. The tempo cross delay is an 8-beat echo.
Which brings me to a necessary ingredient: crunch. 8Z Heavy Hearts gets a lot of its appeal from the Lo-Fi effect:
# Parameter Val Hex Meaning -- -------------------------- --- ---- -------- 1 Sampling Frequency Control 4 0x04 8.82kHz 2 Word Length 98 0x62 3 Output Gain 7 0x07 0dB 4 LPF Cutoff Frequency 56 0x38 12kHz 5 Filter Type 1 0x01 PowerBass 6 LPF Resonance 63 0x3F 6.3 7 Bit Assign 4 0x04 8 Emphasis 1 0x01 On 10 Dry/Wet 88 0x58 D<W24 15 Input Mode 1 0x01 Stereo
Since we need Lo-Fi on both style parts 9 and 10, I configured the variation effect as an XG SYSTEM effect. Parts 9 and 10 also require variation send (MIDI CC#94) set to 127. Add a CC#94 message to parts 9 and 10 in the set-up measure. Here are the MIDI System Exclusive messages to add to the set-up measure:
At this point, you could save the MIDI to “DresdenAtNight.sty” and load it into your arranger as an SFF1 format style. The arranger should create the style CASM segment. As an alternative, you can add a CASM segment to the SMF with JΓΈrgen SΓΈrensen’s CASM editor. You might as well download his OTS editor, too, and use it to add OTS voice settings to the new style as well. Or, you can do this sort of work on your arranger itself. Mid- and high-end Yamaha arrangers save styles as SFF2 format, which is one way to convert from SFF1 to SFF2. I highly recommend JΓΈrgen’s site, tools and style creation tutorial.
BTW, you can recreate Dresden At Night on MODX (Montage). Create a new MODX performance with 8Z Heavy Hearts and Dark Bass. 8Z Heavy Hearts has the appropriate arpeggios by default. You’ll need to assign different arpeggios to the Dark Bass part. Modify effects as needed. Choose and add pad or lead voices to give your right hand something to do. Done! Use the Scene buttons to switch arpeggio groups.
Checking out organ-related threads in the music forums, combo organs get short shrift while most folks focus on the Hammond B-3 tonewheel sounds. Today’s post will (almost) ignore the B-3β¦
Organ-focused keyboards from Nord, Hammond, Yamaha and others have combo organ emulations in addition to tonewheel synthesis. All offer two vintage flavors: Vox and Farfisa. Nord and Hammond throw in pipe organ, piano, EP and instrument emulations, too, making for full all-rounders.
Drawbar control abounds! In the case of Vox, each physical Nord drawbar corresponds to a Vox Continental drawbar footage (with possible extensions). Nord Electro 6, for example, offers 16′, 8′, 4′, 2′, II, III, IV and sine. The 16′, 8′, 4′, IV and sine are basic Continental tones. Nord’s emulation kicks the basics up to dual-manual, Continental II territory by adding a 2′ footage and two overtone mixtures, II and III. The mixtures consist of the following ranks:
II: 5 1/3′ and 1 3/5′ pipes
III: 2 2/3′, 2′ and 1′ pipes
IV: 2 2/3′, 2′, 1 3/5′ and 1′ pipes
The III and IV mixtures add the Hammond-like overtones missing from the original Continental. Hammond employ a similar Vox drawbar assignment in the Sk1/Sk2 series.
Discrete voice (tab) stops pose a minor problem: How to provide discrete On/Off control with sliders (drawbars)? In the case of Farfisa emulation, Nord and Hammond assign each Farfisa tab to a drawbar:
The Hammond voice set is the same as the Farfisa Combo Compact. The Combo Compact Deluxe replaced the Piccolo 4′ voice with a bright 2 2/3′ overtone tab, adding a bit of Hammond-like whistle. The Nord voice set covers the Combo Compact Deluxe model.
Yamaha have taken their own approach to combo organ emulation with the YC61. The YC61 synthesizes tonewheel tones through Virtual Circuit Modeling (VCM) that emulates the sound of analog tonewheels and associated circuitry. Vox (YC61 organ model F2) and Farfisa (model F3) sounds are produced using frequency modulation (FM) synthesis. The YC61 also provides a sine wave “combo” model (F1). The YC61 drawbars bring in the usual drawbar footages with the exception of the 1′ drawbar which is disabled in all FM models (F1, F2, and F3).
Gotta wonder if we can port the F1, F2 and F3 FM organs to Montage and MODX?
Thanks to the frapping pandemic, I have yet to play a YC61. (Grrr.) However, I have played the Nord Electro 6D and Hammond Sk1. Both provide excellent combo organ sounds. Pipe organ (Nord and Hammond) is a big plus for a church player. I give Nord’s orchestral samples and library the edge over Hammond.
Yamaha Reface YC
Yamaha Reface YC promises tonewheel and combo organ sounds on the cheap. By and large, it delivers. I have really worked the Reface YC as a rehearsal instrument and as a gig instrument in church. That said, here are some detailed observations (positive and negative).
Reface YC Typical Vox and Farfisa settings (Source: Yamaha)
I roll my eyes a bit whenever anyone posts about how they “wish the Motif XF (Montage, MODX) had the Reface YC technology inside.” News flash, the Reface YC shares much of its technology with Motif XF, Montage and MODX already. Yamaha simply repackaged and revoiced the basic AWM2 DNA in a wonderfully accessible form. Wisely, Yamaha reacted to the warm user reception and reaction caused by the YC and its popular pal, the Reface CP. Yamaha is now taking it to the bank with the current full-sized CP and YC keyboards.
The Reface YC emulates five different organ models:
H: Hammond tonewheel
V: Vox transistor organ (1960s)
F: Farfisa transistor organ (1960s)
A: Acetone transistor organ (1970s)
Y: Yamaha transistor organ (1972)
The Reface YC drawbars, buttons and sliders directly map to Hammond organ drawbars and controls. What about the combo organs?
I stripped away all of the effects (percussion, chorus, distortion, reverb, etc.) and sampled each of the five voices (8′ foot pipe, middle C). The five waveforms are pictured below. The H and V waves, especially, have a sinusoidal shape. The nasal F wave is truly unique. [Click image to enlarge.]
Reface YC waveforms (middle C, 8′ organ stop)
Since the Vox Continental had drawbars itself, the YC drawbars correspond to a single Vox drawbar sound (the V wave) played back at the appropriate footage (pitch). The YC Vox is based on a single Vox wave, just like the Montage (MODX and Motif XF). In Montage land, this is the “Vx Drawbar1-3” waveform. In the “you get want you pay for” department, the YC Vox does not have the reed and sine drawbars/sounds, and you must dial in the II, III, and IV mixtures yourself.
For the sake of authenticity, one should never put a combo organ through the rotary speaker effect. Trust me. Most of us in the 60s could barely afford an organ and an amp, let alone buy a Leslie. Then there is the issue of getting to the gig. Everything needed to fit into the back of Dad’s car!
The YC Farfisa, Acetone and Yamaha organ implementations follow the same design as the Vox. Each of the four combo organs (V, F, A and Y) consist of a single wave played back at different pitches according to drawbar footage.
Listening to the stripped down F wave, my first thought was “Accordion!” The 60s Farfisa organs were designed by accordion makers and I believe that the raspy Farfisa tone is their intentional attempt to build an electronic accordion. [Memories of Mom and Dad saying, “Why don’t you play accordion and learn a few wedding songs?” Who knew?] The name “Farfisa” is a contraction of “Fabbriche Riunite De Fisarmoniche”, the company formed by pre=World War 2 Italian accordian makers Settimio, Soprani, Scandalli, and Frontallini. It ain’t an accident, folks.
Thus, in terms of control, the Reface YC is quite unlike a real Farfisa Combo Compact with its discrete voice tabs. Once again, you pay more for Nord or Hammond and you get more authenticity. That doesn’t mean you can’t get a decent Farfisa tone out of Reface YC. It’s raspy enough for Wooly Bully and other cover songs. The chosen F wave is versatile and, well, Farfisa voices are pretty much the same wave filtered differently. The screaming Tone Boost is missing in action, though.
I give the Reface YC an A- and B+, respectively, for Vox and Farfisa authenticity. I don’t have any direct experience with Acetone and early Yamaha organs — just the soundtracks of old Japanese kaiju (monster) movies. The YC sounds realistic enough.
I experimented with YC percussion in isolation, too. Each of the Reface combo organ voices has its own distinctive percussion. I recommend trying this at home as some of the settings are almost clav-like and would do in a pinch. A few settings remind me of the 1970s Crumar Roadrunner electronic piano — the most crap-tastic electronic piano ever made. Yes, I owned one, played one, and sold it off as fast as humanly possible. π
The Crumar D9U is a DIY, Arduino-compatible drawbar kit. This series of articles describe my experience from beginning to end and include C code. Don’t want DIY? Then try the ready-made Crumar D9X.
Contemporary workstation instruments offer several options for combo organ emulation. Every workstation has at least a few internal combo organ waveforms. Korg Kronos, for example, has two Vox organ waves built in. Even the lowly Korg microKorg XL+ has two Vox waveforms (DWGS single cycle).
Yamaha MODX and Montage — my focus in this article — have a good variety of Vox and Farfisa waveforms. Yamaha Genos has a lesser endowment as we’ll see. Yamaha Reface YC shares sonic DNA (AWM2 and effects) with the Motif XF and will be the subject of a future post.
Motif, Motif ES and Motif XS
Models in the early Motif series primarily base combo organ patches on two waveforms:
Portable Electronic: Vox-y tone
Compact Electronic: Farf-y tone
You can hear these waveforms at work in the Tiny Combo Bars 1 performance and the Tiny Combo Bar 2 performance. The patches layer three are more elements playing Portable Electronic or Compact Electronic (respectively). Each element is filtered differently: low pass, band pass and high pass. The net effect is like several distinctive tab stops or drawbars pulled at once.
These waveforms are very old, going back to the original Motif (maybe S80) in the early 2000s. I’ll bet dollars to donuts that the Portable Electronic waveform is the basis for the 60’sOrgan voice (MSB: 0, LSB: 116, PC: 18) in PSR and Tyros keyboards. The 60’sOrgan voice was the sole combo organ mainstay in the arranger line for a loooong time.
Motif XF, Montage, MODX
Motif XF got a big shot of combo juice. Motif XF added several combo organ waveforms:
Fr All Tabs
Fr Bright Boost
Fr Flute
Fr String Lo
Fr String Hi
Fr Trumpet
Fr Piccolo
Fr Pedal
Fr KeyOff
Vx Drawbar1-3
Vx DrawbarIV
Vx KeyOff
The Farfisa (Fr) waveforms support emulation of specific Farfisa features: individual voice tabs (flute, string, trumpet and piccolo), the wicked Bright Boost knee lever, bass keys (pedal), and key off sound. The Fr All Tabs waveform covers one of the most common use cases — all of the tab stops turned on. Subtlety was not a hallmark of sixties combo organ music. π
The Vox (Vx) Vx Drawbar1-3 waveform covers the three Continentel footage drawbars while the mixture drawbar is handled by the Vx DrawbarIV waveform. The Vox waveforms include a Vox key-off noise.
In terms of voice programming, one uses note shift to achieve different footage ranks. Passive filtering is emulated through filter type (low pass, band pass, high pass) and cutoff frequency. Of course, everything can be routed into insert effects for distortion, amp simulation, and other grunge.
Since Montage and MODX inherit all things Motif, these waveforms and the Motif performances are there for you. The Montage and MODX sliders allow control over individual voice elements. For example, choose the Raspy Tabs performance and assign slider control to element level. The Fr Raspy Tabs waveform-to-element assignment is:
El# Waveform KeyLo KeyHi VelLo VelHi Coarse Level Cutoff XA Ctrl --- ------------ ----- ----- ----- ----- ------ ----- ------ ------- 1 Fr String Lo C2 G8 1 127 0 97 255 Normal 2 Fr Trumpet C2 G8 1 127 0 82 255 Normal 3 Fr Flute C2 G8 1 127 24 120 236 Normal 4 Fr Pedal C-2 B1 1 127 0 127 160 Normal 5 Fr String Hi C2 G8 1 127 19 24 236 A.SW2 On 6 Fr KeyOff C2 G8 1 127 6 87 80 Key Off
Different tabs are brought in and out by moving the corresponding slider. Assignable switch 2 turns on additional brightness. The low keyboard octaves play the bass (pedal) tones. Overall, this is a fairly controllable representation of a wheezy Farfisa Compact.
Because the sliders are not discrete, you can probably make up Farfisa tones which aren’t entirely authentic. But, really, should one care? π
Vox performances have similar control-ability. Here is the waveform-to-element assignment in the Vx Full Bars performance:
The first three sliders control the 16′, 8′ and 4′ Vox drawbar settings and the fourth drawbar controls the Mixture (IV) tone. Go ahead, just everything to eleven. π
Montage and MODX FM
But, wait, there’s more! Montage and MODX have two FM combo voices: BOX FM Combo Organ and FM YC Combo Organ. Although these performances don’t sound authentic to my ears, they provide starting points for further programming. I haven’t heard the YC61 as yet, but I wonder if the YC61 combo emulations can be ported to Montage and MODX?
Genos
As I mentioned earlier, the arranger series has been historically short on combo organ sounds, relying on the old 60’sOrgan voice. Wheezy, raspy Farfisa tones are noticably absent. The 60’sOrgan voice sounds like the Portable Electronic waveform on which the Motif 1967 Keys performance is based.
Tyros 4 and Motif XF were introduced at approximately the same time. They certainly were together in the development lab during late 2009. Tyros 4 added four combo organ voices:
60sComboOrgan1: VoxContiComb1_Full_NoVib waveform
60sComboOrgan2: VoxContiComb1_Full_VibOn waveform
60sComboOrgan3: VoxCombi4NoVib waveform
60sComboOrgan4: VoxCombi4NoVib091117 waveform
Voices 1 and 2 capture one Vox Continental drawbar combination (Comb1) and voices 3 and 4 capture a second combination (Combi4).
Voices 1 and 3 are without vibrato. Voices 2 and 4, unfortunately, have an excessive amount of vibrato — almost painfully so. When I use voices 2 and 4 in a MIDI sequence, I dial down the vibrato depth using MIDI CC#77 messages. Vibrato frequency is about 5Hz. I also remove touch sensitivity by setting:
Velocity sensitivity depth to zero, and
Velocity sensitivity offset to 114.
An organ voice should not respond to touch (key velocity) — ever.
PSR, Tyros and Genos players shouldn’t forget the “hidden” Italian 60s organ voice (It60’sOrgan) in the GM2 sound set. On PSR and Tyros, you’ll find It60’sOrgan within the Legacy voices Organ subfolder. On Genos, you need to download GM2 and XG user voices to the USER voice folder. (See this thread in the PSR Tutorial Forum.) Of course, you can select It60’sOrgan from a DAW (MSB: 121, LSB: 2, PC: 17) .
All-in-all, you can get a nice Vox tone out of Genos. Farfisa is still missing in action, tho’. Kind of an odd shortcoming of a keyboard with styles and a user base that want to play popular hits from days past.
In the next post, I’ll compare Reface YC combo organs against Montage/MODX (Motif XF). The result may surprise you.
Discussions about Yamaha Montage/MODX AWM2 and FM-X sent me digging into the past to unearth early AWM and FM implementations in order to get insight into today’s tone generation hardware. Although Yamaha do not publish design information about their proprietary SWP, SWX, SWL, etc. processors, they have published datasheets for their merchant line of LSI products. Yamaha were very active in the mid- to late-1990s when desktop music (Soundblaster, XG, Sondius, etc.) was king.
The Yamaha YMF278B OPL4 was one such LSI component. The OPL4 combines a 2-/4-op FM synthesizer and a wave table synthesizer on a single 80-pin quad flat pack (QFP). The FM synthesizer can:
Generate 18 voices in 2-op modes or 15 2-op voices plus five rhythm sounds.
Generate 6 voices in 4-op mode with an additional 6 voices in 2-op mode, or 6 voices in 4-op mode with an additional 3 voices in 2-op mode and five rhythm sounds.
The FM synthesizer has eight selectable waveforms and generates a stereo output. The wave table synthesizer can generate 24 voices simultaneously (i.e., 24 voice polyphony) producing stereo output at a 44.1kHz sampling rate with bit depths of 8-, 12- and 16-bits. Wave ROMs up to 32Mbits are supported with up to 512 wave tables.
The OPL4 has six sound channels which can be sent to an external DAC (YAC513) or a digital effects processor (YSS225). Sadly, documentation for the YSS225 cannot be found on-line. The YSS225 is said to perform reverberation, echo, flange and other effects.
The FM and wave table synthesizers are two separate hardware units. I wouldn’t be surprised if this is still the case in the modern day SWP70 Standard Wave Processor. Separation lets the engineers optimize the synthesis hardware for a particular synthesis type.
Wave table synthesis
The OPL4 does not implement AWM2 synthesis. The synthesizer does not have the AWM2 filter hardware. This is not too surprising because in that era, Yamaha regarded AWM2 and its analog-like filter as a special competitive advantage. Why would they give that same advantage to other sound card vendors? It’s a safe bet, however, that the XG-compliant variants are full AWM2.
Nonetheless, a peak inside gives us a look at Yamaha’s wave table machinery. The synthesizer consists of a synthesis core that fetches waveform samples and waveform meta-data from external wave memory.
YMF278B block diagram
Quoting the OPL4 data sheet:
The wave table synthesizer can generate up to 24 sounds simultaneously. Each sound is referred to as a “channel”. The channels are numbered from 1 to 24. These numbers are called “channel numbers”.
Wave table synthesis is controlled by a few hundred registers. The main control CPU writes common and channel-specific synthesis parameters into the registers. The synthesizer reads the registers during each synthesis macro-cycle and produces a new sound sample for each channel. The channel-specific control registers are organized into register groups. Each group consist of 24 registers, i.e., 24 values of a specific synthesis parameter type, one value per channel. A quick glance at the table below clarifies the register organization and the wave table synthesis parameters. Parameters for envelope generation, pan, LFO control, etc. are easily identifiable. (The YMF278B data sheet has the details).
YMF278 wave table synthesis control registers
I conjecture that today’s SWP70 is organized in a similar way. The CPU-SWP70 communication bus is a memory bus that gives the CPU direct access to the SWP70 synthesis control registers. Think about it. With 128 stereo AWM2 channels, there are several hundred (thousand!) synthesis values which must be configured at the hardware level. Software’s job is easier and fast by making the synthesis registers (channel-specific parameter value) directly accessible.
Wave table in external memory
The waveform data and meta-information in external memory cosnsist of two parts: Up to 384 waveform headers and the waveform sample data. Each waveform header is 12 bytes containing:
Wave data start address
Loop address
End address
Voice parameters: LFO, VIB, ADSR, etc.
Today’s wave table is probably similar albeit much bigger. Explore Yamaha’s Universal Voice Format (UVF) and you’ll see what I mean.
FM synthesis
The OPL4 supports 2- and 4-op frequency modulation (FM) synthesis. Quoting the data sheet:
The part that generates one sine wave is called an “operator”. A combination of these operators is called an “algorithm”. The first stage operator (see diegram below) is called the “modulator” and the second stage operator is called the “carrier”. The frequency and envelope can be set for each operator. “Feedback FM” is available to generate a wider range of sounds.
Basic FM system
Feedback FM system
Like the wave table synthesizer, the FM synthesizer has a large table of common and channel-specific synthesis parameters. The register table organization is a little more complicated. Quoting:
The OPL4 has 36 circuits that generate a sine wave. A circuit which generates a sine wave is called a “slot”. A sound unit which is generated by combining two or four operators is called a “channel”.
There are two kinds of sound generation control registers: registers settable in slot units and registers set in channel units.
In 2-op mode, two slots are used to generate on FM sound. With 36 available slots, 18 channels of sound can be generated. In 4-op mode, four slots are used to generate one FM sound. Six channels are generated using 24 slots.
YMF278 FM synthesis control registers
Whew! Given the two dimensional nature of register organization, addressing a specific parameter value for a specific operator is a complicated matter. (See the data sheet for details.) Without going a deep dive into register addressing, here is an image showing common and channel-specific synthesis parameters.
YMF278 4-op algorithms
Summary
I would say that the overall architecture today (SWPxx) is not unlike the architecture of yesteryear. The number of synthesis parameters, of course, has exploded with new features in the wave table synthesis hardware (filtering!) and FM synthesis hardware. Modern FM can route FM output samples to AWM2 wave table filters, adding many wrinkles to datapath and control design.
The main CPU is responsible for channel allocation as notes are played and for channel deallocation as notes are released and completed. Once a channel is allocated, the main CPU must write the appropriate voice parameters into the channel registers. Then, it’s up to the synthesizer hardware to crank out a new sound sample at a 44.1kHz rate. Of course, the per-channel sound samples must be mixed and routed to the DSP effects processors. I would love to get a look at the mixing and DSP processing.
I hope this trip into the past gives you some insight into present-day AWM2 and FM-X hardware and an appreciation for the complexity and sheer number of details at the 10,000 foot level of digital synthesizer design.
Yamaha hold many patents on wave table and FM synthesis techniques. I recommend U.S. Patent 5,250,748 (1993) which describes the digital filter in AWM. For the modern era, I suggest U.S. Patents 8,779,267 (2014), 8,957,295 (2015) and 9,040,800 (2015).
There’s been an extended discussion in the YamahaSynth.com Montage Forum about the ability to add Virtual Analog (VA) synthesis to the current Montage and MODX platforms. It’s been a good discussion and it encouraged me to jot down a few musings about the hardware support for AWM2 and FM-X.
In case you don’t visit YamahaSynth.com, I reposted my musings here and added a diagram or two.
Before saying anything, I have to emphasize “Speculatively speaking.” With as much invested in AWM2/FM-X and their implementation in silicon, Yamaha have not published about the internal design. This whole discussion — including my own comments — would be on much sounder footing (no pun intended) if the micro-architecture were published. Yamaha are tight-lipped so “Hah!” to us all. π
BTW, we’re lucky that we can speculate at all since Korg, Nord, etc. have largely buttoned up their service manuals.
I’m skeptical
I’m skeptical about adding VA through an update given the current platform because of limitations in the current synthesis pipeline.
Yamaha regard their expertise in large scale integration as a strategically important asset. (Please see their annual financial reports.) The SWP70 is a major investment in the future. It’s a generational step and a design with a long expected life time. A long life is needed in order to recoup Yamaha’s investment. Thus, we haven’t seen all of its potential capabilities as yet.
At some point, the current hardware platforms (Montage and MODX) will limit the features which can be delivered solely through software. That will necessitate a new hardware model in each product line. Speculatively speaking, I’m not sure if the SWP70 is capable of CS-like VA synthesis. The Reface CS (and DX) employ a Yamaha SSP2 (SH-2 CPU core) for synthesis. The mere presence of an SSP2 in the Montage is not significant for VA because it clearly supports UR-like digital audio in the existing design.
Of course, business decisions will take precedence eventually. We all love the free updates and improvements in our instruments. (I certainly do!) Like cellphones, tablets and other high-end electronics which enjoy periodic updates, we will need to buy a new upgraded platform in order to fuel the future. Nobody rides for free forever.
My mental model
I suspect that we nerds (and I mean that as a compliment!) have different architectural models in mind as to the SWP70 internals. One model is the “standard DSP” model — a pipelined single instruction, single data (SISD) CPU. Naturally, there may be enhancements for vector processing instructions and so forth.
An example of such a generic model is the Yamaha SSP2, which consists of an SH-2 DSP core and several effect DSP processors. The SSP2 is the heart of Reface CS with an internal clock of 135.4752MHz (a multiple of 44,100Hz, BTW). Another example would be the DSP56362 in early Nord/Korg modeling keyboards. The Reface CS manages 8 voices of polyphony (using the word “voice” loosely) with the effects handled by the SSP2 effect DSP processors. (The effect DSP processors are mini, small core, reprogrammable processors.)
The architectural model which I think is used in the SWP70 is a SIMD architecture more akin to a GPU. The Montage/MODX DSP RAM and wave work RAM memory clock is 95.9616.MHz, also a multiple of 44,100Hz. The SWP70 pumps out a finished sample every 2,176 memory clock ticks. The internal clock is probably a small multiple (maybe two) of the memory clock. Everything needs to run in a modest power envelope without a heat sink, etc., so it’s not possible to run at GHz rates.
After writing this, I realized that the AWM2/FM-X synthesis core may not have an instruction stream at all. It might be a block of 1 to N dedicated pipelines where each pipeline is, roughly speaking, an AWM voice element.
I image a block of tone generation (TG) cores dedicated to AWM2/FM-X. Part of that “dedication” is a pipeline specifically tailored and tuned to AWM2/FM-X. (I believe this design IP (the basic core design) is re-used in other AWM2 products.) Yamaha are in the AWM2/FM-X business so it makes sense to design hardware specific to these tasks. It’s no simple feat to produce 128 channels of tone generation with low latency and no burps and hiccups.
I don’t know how much flexibility is built into the so-called “oscillator” part of a TG core pipeline. Could Yamaha write a new SIMD program for VA using the existing TG core design? I don’t know and hence, my doubt.
That said, since Yamaha haven’t published a darned thing and my job easier (Hah!), I could be totally wrong. Yamaha are smart engineers, especially at the hardware level.
The choices made for Reface may or may not be revealing. Reface YC/CP use the SWX08 for AWM2/SCM synthesis. The SWX08 — in my imagination — use a similar AWM2 TG core assist. Reface DX/CS use SSP2 and its SH-2 core. Was something missing in the SWX08 TG core which was available later in the advanced SWP70 cores? Did SWP70 become VA capable as well?
Example: Yamaha YMW820
The closest I’ve ever gotten to understanding Yamaha’s approach to AWM2 is by studying the datasheet and MIDI spec for the YMW820 (NSX-1). Admittedly, the YMW820 is a low-end device implementing a large subset of the XG voice architecture with only chorus, reverb and a single variation effect.
YMW820 (NSX-1) block diagram
The YMW820 has a control CPU (dual issue, 32-bit RISC), mixer hardware, DSP for effects, and a “wavetable synthesis core” (Yamaha’s exact terminology). Both the synthesis core and DSP are controlled by the CPU.
The wavetable synthesis core supports 64 channels (polyphony). The YMW820 has a 2MByte wavetable ROM which presumably contains the General MIDI waveforms. It also has a 3 MByte wave RAM which can be loaded with eVocaloid waveforms or Real Acoustic Sound (Articulation Element Modeling).
The 64 channel synthesis core is drawn as a distinct hardware subsystem from the effects DSP. Each channel is what we consider an element: pitch generator, oscillator, digitally controlled filter (DCF), envelope generator (EG), LFO. I suspect that other AWM2-based products have similar wavetable synthesis cores, including the SWP70. [Click image below to enlarge.]
YMW820 (NSX-1) synthesis core and effect DSPs
Of course, the SWP70 synthesis core is the ultimate in the entire AWM2 family. It also has many effect DSPs for system and insertion effects.
Bottom line, Yamaha exploit massive parallelism for AWM2 synthesis where each channel is a wavetable synthesis element. A true DSP processor like the SSP2 is better suited for VA synthesis which is why the SSP2 is deployed in the Reface CS, not an AWM2-oriented SWX processor. (The SWX has an embedded wavetable synthesis core, too.) I believe that Yamaha will need to add another SSP2 (or some such) to the Montage in order to implement VA. There’s a reason why it’s called a “Standard Wave Processor” — it is hardware specifically designed for AMW2, FM-X, AEM, and SCM synthesis. It isn’t a general purpose programmable DSP. Maybe VA can be warped to the existing pipeline(s), maybe not.
BTW, the new VCM MINI FILTER and MINI BOOSTER are DSP effects. The effect DSPs are programmable — the AWM2 channel filters likely are not.
Big DSP vs. little effect DSPs
I tend to think of the internals as a tone generation front end followed by a flock of small DSP units in the mixer/effects back-end. This seems to be the canonical Yamaha pipeline. In Montage/MODX, some of the small DSPs are routed as insert effects and some as system/master effects. (The effect routing in Genos, BTW, is different and probably different in the high-end digital pianos.) I suspect that the data flow is predominantly (solely?) front to back.
I don’t really know if the small effect DSPs are general purpose or not.They are probably small simple cores because an SWP has at least 15 and real estate is limited. (Lower capacity parts like the SWXs and SWLs have far fewer small DSP cores.) A small core may not have much throughput and the front-to-back dataflow might prevent feeding data from the DSP cores back to the filters, etc. in the front-end.
There is also the issue of getting note and controller data to the effect DSPs in the back end. Note and controller data are delivered on the E-bus directly from the key, knob, slider, etc. scanning processor(s) to the tone generation core. Does all E-bus data get back to the small DSP cores? Certain some data gets through as knobs, sliders, etc. can tweak effect parameters in real-time.
Overall, even as a consumer, I would be happier with a dedicated SSP2 for VA. The VA SSP2 would inject its digital output stream into the existing mixer/DSP infrastructure. [The SSP2 vocal harmony processing does something like this in Tyros5.] The VA SSP2 gets its own DSP RAM and NOR flash for program, and the processing is totally out of the way of FM-X and AWM2. It would be possible to implement different VA algorithms without making compromises. Yamaha could periodically offer new engines as updates/upgrades.
If you’re an ARM aficionado, you might be thinking “big.LITTLE”. It’s a similar concept. Engineers need to make best use of limited real estate. Yamaha need lots of little DSPs for insertion effects. The SSP2 itself is organized as a big SH-2 DSP core and several little effect DSPs (plus a digital mixer). The mix of channel strip and guitar effects is limited.
Down memory lane
The discussion took me down memory lane to the venerable AN-200 and PLG150-AN. Both products use Yamaha’s AN (Analog Physical Modeling) daughter card. I love the old AN-200 and keep one handy. It is a pretty decent approximation of a five voice Prophet 5.
The daughter card contains two Yamaha LSI components:
YSS-236-F: An enormous 160 pin QFP for analog synthesis
YSS-233-F: A merely huge 128 pin QFP for mixing and effects
The 236 is also known as the “VOP3” and the 233 is known as the “MDSP”. The MDSP is deployed in the PLG150-DX daughter card, again in the mixing and effects role. The An1x, by the way, has two of each, implementing ten voice polyphony.
Some sites ascribe synthesis to the Hitachi H8/3002 on the daughter card. This is wrong. The H8/3002 is the microcontroller that issues commands and maintains digital communication with the mothership. The VOP3 does synthesis.
The VOP3 moonlights as the vocal harmony processor in early arranger keyboards like the PSR-9000. The VOP3 is the predecessor to the SSP and SSP2. The SSP and SSP2 subsume the mixing and effect DSP roles of the MDSP. Such is the march of large scale integration (LSI) fabrication technology.
Given this history, I’m not surprised that Yamaha chose the SSP2 for Reface CS.
I like surprises
Watch, Yamaha will come up with something completely different. π Maybe an SWP71. There were different spins of the SWP50 family, so why not? π From the marketing point of view, demand for VA is sufficiently high that they may require everyone to buy a new platform anyway. Perceived value means “mo’ money.”
