The GM Voice

Thomas Henry

Okay gang,

This one took me way too much time to complete, but I'm ready to start spilling the beans.

What it is: The GM-Voice is a standalone, MIDI driven multiple voice unit. It can create hundreds of pre-programmed high quality instrument sounds---some natural, some electronic---in addition to dozens of percussive instruments. Best of all, the voices respond to dynamics and you can play a minimum of 24 simultaneously! GM stands for General MIDI, as if you hadn't figured that out already.

Total outlay? About $25, if you know how to shop. This is probably the least expensive way to outfit a home recording studio with high quality sounds I can think of.

Here's the scoop. A decade ago our own esteemed Antman wrote me a note on his researches into the possibility of a standalone GM circuit. I was absolutely up to the gills in projects at the time and it's only recently I've been able to return to what he had originally proposed. Moreover, Antman was able to get me the crucial raw ingredient for ten bucks on Ebay a month or two ago, and it's all been downhill since then.

This project takes a Soundblaster type daughterboard, adds a little support circuitry and voila---the computer isn't even needed to extract its magic. It becomes a standalone instrument for the studio.

This is my first joint project with Antman, and it's been a great success. I hope we can encourage him to submit a general overview of the project, the overall process and some purchasing tips for newcomers. (I still have some of your letters from a decade ago---can I post them for general info to builders?) And then, I'll supply the new and improved schems, along with PCB artwork and wiring info.

Here are the features I've included in the Antman/Henry version of the GM-Voice:

- reset button providing emergency all-notes-off action
- MIDI In
- two MIDI Thru jacks
- stereo and mono outputs
- fully buffered outputs for maximum protection
- improved MIDI activity LED shines brightly!
- internal power supply for true standalone performance
- carefully worked out digital/analog grounding for optimal performance

Attached are two photos of my unit. I only have a $25 digital camera, so the quality is a bit punk. but you'll get the general idea. The whole thing is about the size of a brick and looks very nice.

Okay Antman, care to jump here?

Thomas Henry

GM Voice-front.jpg

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Front panel of the GM Voice

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Guts of the GM Voice

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Thomas Henry · Posted: Tue Nov 06, 2007 10:02 pm Post subject:

Hi again,

I forgot that Antman had already started a thread elsewhere with some of the background on this project:

http://electro-music.com/forum/post-149503.html#149503

Go there for the prerequisites, and then stop back here as we fill in the schems, PCB artwork, etc.

Stay tuned!

Thomas Henry

The Alison Project · Posted: Tue Nov 06, 2007 11:27 pm Post subject:

Looks interesting, looking forward to hearing some samples.

Chris

Thomas Henry · Posted: Wed Nov 07, 2007 6:11 pm Post subject:

Hi gang,

Are we ready for some schematics? I'm still in the thick of things at school (not to mention helping to get the MPS ready to go), but managed to find time today to finish up the schems and all the stupid scanning activity that goes with it. I hope someone will find these useful.

Stay tuned...I should be able to post the PCB artwork in a day or two barring a certain inconvenience. Did I mention that we have an all-day meeting on Friday? But the college provides the donuts and coffee free of charge...

Anyway, here are the schems and parts list. This really is a cool project, so tuck in.

Thomas Henry

Sheet 1.pdf

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GM Voice Schematic- Sheet 1 (.pdf format)
May not be reproduced without permission of Dan Lavin and Thomas Henry;
instead, send interested DIY-ers to this link at EM.

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Sheet 2.pdf

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GM Voice Schematic - Sheet 2 (.pdf format)
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Sheet 2.pdf

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Parts List.pdf

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GM Voice - Parts List (.pdf format)
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Dan Lavin · Posted: Wed Nov 07, 2007 8:34 pm Post subject:

Thomas,
Thanks for finishing this up. Now I think this may perhaps be theee longest project here on the E-M Forum: ~10 years!!
Scott, thanks for moving my other post over to the TH Designs forum. It definitely makes it easier on folks to track down.

Just a few personal notes on this project:
1. Interestingly enough, Thomas has created a desktop module. When we started 10 years ago, I was going for the desktop mounting and bet Thomas he couldn't resist a rack panel due to his track record. So I went ahead and built a 1u rack panel! It still resides proudly in my main rack.
2. I am in the process of building 2 master midi keyboards: a 4-octave unit with pitch and mod wheels and a 5-octave one with a joystick. Both will contain a Gm Voice. The 4-octave one is complete and I wrote it up on the DIY forum. That unit has the same card that Thomas has. The 5-octave joystick unit will have a Yamaha db50XG board.
3. Thomas added the reset button because his unit had trouble a couple times with the RC reset. I've never had any problems and do not have a reset button on my 3 units. I did notice that i used a 47uF cap instead of the prescribed 10uF one.
4. Searching for a card on ebay....a little harder than a normal ebay search. My best finds are just searching for a "soundblaster" under computer desktop peripherals and examining the posted photos. The cards are daughterboards, so if you see a soundblaster with a board stuck to it, you're in luck. Quite often, the seller doesn't even mention it.

Sorry I've been a little quiet lately. I've been tied up with Boy Scouts (camping out this weekend in below freezing conditions!), finding a college for my high school senior daughter, traveling for work, etc. I'll try to get a photo of my rack mount GM Voice and post some public domain midi files playing these things.

Thomas Henry · Posted: Wed Nov 07, 2007 9:49 pm Post subject:

Hiya Antman,

Qwitcherbellyaching about the camping! The neighbor lady across the street has kicked her 50 year old son out of the house and he's currently bivouacking in their back yard. This is Minnesota we're talking about and it's been in the low twenties lately!

Thomas Henry · Posted: Fri Nov 09, 2007 9:01 pm Post subject:

Hi again, gang,

As promised, here is the artwork for the GM Voice project. (I survived a grueling 8 hour meeting full of educational mumbo-jumbo today, and yet managed to massage this all into a postable form tonight).

The PCB artwork actually has three boards in one: the interface board, the power supply board and an optional 26-pin connector board. The latter is used to connect the system to your daughterboard. J7 is a 26 pin connector; I sawed down a larger one to solder up my own connector cable, but perhaps you can find a standalone cable and connector and avoid this phase. Also note that you can cut up the three boards like I did after etching, to allow placing the various submodules tidily inside a reasonably small enclosure. If space isn't an issue for you, just make it all on one board and fit it all behind a 1U rack panel.

You'll find .pdf files for the lifesize PCB artwork and the parts placement guide. The labels (along with the schems posted earlier) should make everything clear. But to make the most of this excellent project (hey---getting a couple hundred high quality voices all at once for $25 can't be called anything less), please follow the power supply runs and grounds to the boards and panel very carefully. Digital grounds and analog grounds have a way of tussling more than the Fabulous Moolah with Bobby "The Brain" Heenan, if you're not careful. You'll note on the parts placement guide that there are various multiple pads on the power supply and the interface boards. Use them like this:

Analog Ground:
a. daughterboard
b. interface board
c. front panel

Digital Ground:
a. daughterboard
b. interface board
c. MIDI jacks J2 and J3, and switch S1

+5V:
a. daughterboard
b. interface board
c. LED D7 on the front panel

If you follow these routes, then digital and analog ground only connect at one point (the power supply).

Also note the power supply was so compact, that C6 wasn't needed. So, C6 does not appear on the PCB design I've attached. If you're doing your own design and the +12V supply is far away from the 7805, then use both C8 and C6.

Want to know the currents? Well, the -12V supply draws almost nothing, less than 10mA. The +5V supply draws around 40mA, and the +12V around 80mA (40mA actually, but it also feeds the 7805). These are all small currents, but I still went with the 7805, 7812 and 7912 just so I wouldn't have to hassle around with heatsinks inside a sealed enclosure. Everything should run cool.

This is one of the neatest projects I've ever been suckered into, and I want to thank Antman once again for pushing me along. The acoustic grand piano is alone worth the price of admission, but then there are those other 200 instrument sounds just waiting!

Finally, it took a lot of dinking around with the artwork (I still do all of my designs "by hand"), so if you found this project useful in your own work, please respond here with your results; Antman and I will be suitably honored. A large cheer from the crowd makes it more likely other projects will appear in the future. Remember, we don't do this for an income (that's why we like electro-music---none of us are here to make money, but to make music and help each other)

Thomas Henry

pcb.pdf

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.pdf file of the printed circuit board artwork.
(c) 2007 Thomas Henry
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Parts Placement Guide.pdf

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.pdf file of the parts placement guide.
(c) 2007 Thomas Henry
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Scott Stites · Posted: Fri Nov 09, 2007 9:48 pm Post subject:

Awesome!!

Thanks to Dan and Thomas for sharing this - OK, Dan, I guess I better follow up on that conversation we started long ago about where to get the daughter board. Is there MIDI in my future? Very Happy

I can't wait to hear samples of it.

elektro80 · Posted: Sat Nov 10, 2007 5:28 am Post subject:

TH, great stuff! This is a cool project!

Thomas Henry · Posted: Sat Nov 10, 2007 11:59 am Post subject:

Many thanks.

Next to come will be some links to docs that will help you access all of the many voices within the thing. I just printed one out, and it's even in color!

Stay tuned...I really think we've hit paydirt here.

Thomas Henry

Scott Stites · Posted: Sat Nov 10, 2007 12:16 pm Post subject:

Is there a list of the available voices anywhere (in case I missed it)?

Thomas Henry · Posted: Sat Nov 10, 2007 2:10 pm Post subject:

I'm working on it at this very moment. I should have some lists ready to go later tonight. I'm putting them into a form that'll be usable with MIDI-Ox and Cakewalk directly, to save you some typing.

Stay tuned,

Thomas Henry

Thomas Henry · Posted: Sun Nov 11, 2007 1:31 am Post subject:

Okay,

After a hellish day of typing, swearing, formatting and printing, I've got some software docs put together that will let you extract a bit of magic from this module. I haven't even had a moment to sit still and count, but believe there may be well over 200 separate voices at our disposal!

I really did put a ton of time into formatting things here, so be sure to print these pages off and put them into your 3-ring binder. After much research, testing and scouring the Internet for corroborating evidence, I believe this to be the most comprehensive and easy-to-read set of docs for the GM Voice thing ever---even more than what the sound card people provide. (Antman wil back me up that there's not much out there on the documentation front).

These are all the voices I've found. Next up is some research into the chorus/reverb stuff that may be lying dormant in the GM Voice.

Be sure to post your own results here. This may just be the most versatile electronic music gizmo ever if we all pull together.

Thomas Henry

GM-GS Voices.zip

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Zip file containing 6 pages of detailed patch/program .pdf charts for the GM Voice project.
Print them for your notebook!

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GM-GS Voices.zip

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Dan Lavin · Posted: Sun Nov 11, 2007 8:05 am Post subject:

Funny.....I thought the metronome bell sound was a typewriter return bell! But now that I think about it, probably no one under 35 remembers that sound!

I was also able to find the extra sound effects by selecting programs 121-128 and changing the bank number. THe nice part there is the sounds are spread over the keys so you can get simultaneous people screaming for instance: a man, women and little girls, all in glorious polyphony!

I tried to get the chorus and reverb activated by sending controllers 91 and 93 to the card with no luck. Perhaps Thomas will have more luck.

Remember, sound sets and controller info accepted (along with sound quality) will vary somewhat among different mfr. daughterboards.

Thomas Henry · Posted: Sun Nov 11, 2007 10:44 am Post subject:

And if you go here:

http://en.wikipedia.org/wiki/General_Midi#Percussion_notes

there is a nice graphic. Save it to your computer, then print it out full-size and you'll have a great reference sheet for your notebook.

And it's in color!

Thomas Henry

Thomas Henry · Posted: Sun Nov 11, 2007 4:07 pm Post subject:

Dan Lavin · Posted: Sun Nov 11, 2007 5:19 pm Post subject:

Thomas,

To access the polyphonic easter eggs, you need to select program voices 121 thru 128 and use midi controller #0 (which is Bank Select MSB.) You're probably using midi controller #32 which is bank Select LSB. All the easter eggs are found in MSB banks 1-5. There are other in bank 6-11, etc but they are just repeats of those in the first 5 banks.

Easter Egg sounds: muted guitar string, click, low rocket, high rocket, babbling brook, bubbles, dog bark, horse gallop, digital phone ring, zooming car, door slam, clock chimes, car starting, car screetching stop, foot steps, heart beat, laugh, screaming, kung-fu punch, American police car with doppler effect, train over tracks click-clack, turntable scratch up, ray gun, explosion, space ship, jet takeoff............I'll try to create a spreadsheet with the sounds I found. Screaming is found on program 127, MSB bank 2.

I apologize if my description of the sound is not 100% It's just my guess.

Dan Lavin · Posted: Sun Nov 11, 2007 5:36 pm Post subject:

Dear Folks,

Here's some photos on my 2 Gm Voices. One is rack mounted and was built nearly 10 years ago when Thomas and I started this whole mess. It's the purple (yeah, I know Embarassed

) panel in the middle of the rack.

The other is built into my 4 octave midi controller. Note the daughterboard and the interface board built on perfboard to the right.

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Thomas Henry · Posted: Sun Nov 11, 2007 7:48 pm Post subject:

Dan Lavin · Posted: Sun Nov 11, 2007 8:27 pm Post subject:

Thomas,

I checked your new cheat sheet against the notes I made on the extra sound effects and they do match up. Unfortunately some of the samples weren't as obvious as the description. For instance, I thought the thunder and wind were rockets. I think using the right amount of reverb, hitting the center note of the sample, maybe some EQ, etc. will make them work.

crashlander42 · Joined: Oct 21, 2006 Posts: 292 Location: Orlando, FL (US)

I'm excited about this. Makes me nostalgic for my first keyboard and that crappy copy of Cakewalk that came with my gameport MIDI cable.

Is this only good with the Soundblaster daughter board? I think my old Gravis Ultrasound (with MIDI daughter board) is in my garage somewhere.

Thomas Henry · Posted: Tue Nov 13, 2007 7:37 pm Post subject:

Thomas Henry · Posted: Tue Nov 13, 2007 7:41 pm Post subject:

Dan Lavin · Posted: Wed Nov 14, 2007 12:08 pm Post subject:

Well folks, I've done a little more research on the daughterboards and would like to report the following:

1. Additional sources for soundcards: be on the lookout for Roland SCD-15 and the Ensoniq Soundscape DB.
These were Roland's and Ensoniq's (prior to Emu/Creative buyout) answer to Creative's Waveblaster and Yamaha's db50XG.
Since these are first and foremost electronic music instrument companies, I'm sure the quality is quite high.
2. I've never really pursued the Creative Waveblaster itself, but I think I've changed my mind. The chipset
Creative used is none other than the same set used for the Emu Proteus Rompler. I've depended on my Emu Proteus
for live performances for the past 15 years and am still quite satisfied with it. While few of the sounds are
going to blow anyone away, they are dependable and have aged gracefully. The piano, strings and brass and combinations
of those 3 are regular staples for me. Thomas, you are really fortunate to have found one of these. I think it
will blow you away after fooling with the QDSP board you started with.
3. NEW DAUGHTERBOARDS ARE CURRENTly AVAILABLE!!!! It seems our friends in Germany, Terratec, started producing new
daughterboards in 2005 and they are still available!!! Terratec's WAVE XTABLE is unbelievable in specs as well: 16MB memory,
(most cheapo boards are 1-2MB), 128 voices at one time (GM only requires 24!), 628 sounds + 10 complete drum kits and is both
GM and XG (Yamaha's GM on steriods spec) compatible. Terratec's website says it can handle all orchestral arrangements and
the latest electronic and rock sounds. THere is also a SFX kit. It has 4 mounting holes...one is each corner...great for
us DIYers. Now the bad news....it is a little pricey: 149 euros (~US$218 at the current exchange rate). I haven't
priced it on ebay yet, but I'll be prowling now for sure! There seem to be a large number of shops in the UK selling it,
so for our friends there, you may get the best pricing and availability. I'll keep everyone posted as I continue to research these boards

Dan Lavin · Posted: Wed Nov 14, 2007 7:20 pm Post subject:

Ummm.....just when I was excited to find one new daughterboard today, I found yet another:

The DoX-1 adds a high-quality professional MIDI sound module to your MIDI/Audio-file player, upgrading it to a real "all-in-one"-unit.

* HI-Synthesis soundengine by KORG ®
* 62-voice polyphony
* 660 high quality sounds
* 30 drumkits
* 2 effect processors
* GM/GM2 compatibel

MIDITEMP DoX-1
recommended retail price: € 499.- (incl. 19% VAT)

The price is a little steep for me and I doubt the bang for buck factor is there for me after listening to the mp3 samples on the mfr's website, but hey, it's encouraging there are going to be daughterboards around for a while yet!