Muff's Modules & More

[L-1]

Info here http://l-1.su/Vocoder.html

Build thread http://www.muffwiggler.com/forum/viewtopic.php?t=75707


I have decided to post about my new project I'm working now. Maybe it will help me to get some advises and to avoid some mistakes.
I have written somewhere on the forum I repaired 1988 soviet 24 band vocoder. Now I made one channel based on its schematic but with changes. It works, but very hard to understand how it sounds because I have only one channel now. My channel sounds different than soviet analog, I think better but will can say exactly when will make all filterbank.
I replaced crappy old soviet single opmaps with TL074, and replaced transistor pairs VCA with THAT2180 VCA. Anyway DIP trans pairs cost equal to 2180 IC. The channel has turned out much more compact.
I already drew in Eagle filterbank board. 6 channels fit on the eurocard (160x100). So will be 5 boards - 4 for filterbank and one for in-out circuits and controls.
I made CV in and out pads on board for every channel, so if someone wants can make patch matrix.
In-outs circuits I plan completely remake. I think about THAT based mic amp, then (maybe) one knob limiter (THAT), then simply output summing amp (OPA2604) and 4-band EQ.
I drew simply sketch. Green are pots. Blue is hole for mic. connector. Red are 3.5mm jacks and I will make connector for 5U users to connect their BIG jacks. Dimensions between pots will be by MOTM standard http://www.dragonflyalley.com/images/MOTMtech/m440_panel.jpg
Pots:
- mic amp gain
- carrier level
- modulator level
- limiter treshold
- 4 bands of EQ
jacks
- carrier
- modulator
- out.
maybe switches to bypass limiter and EQ, and maybe limiters makeup gain pot.

I like these pots from Smallbear. They are 15 mm - not small as 9 mm and not big as regular 16 mm (they are already sick), and have possibility to mount funny LEDs.
http://www.smallbearelec.com/Detail.bok?no=1186

I think module deep will not exceed max for Doepfer case 14 sm. It can work from 12 and 15 V with minor changes - some resistors values.

I will order next week filterbank prototype boards, they will be ready in one week. Will inform about progress. Please write your comments. Not needed to write who are in, the project is still in its infancy and no one knows what will happen as a result of.



Я ТВОЙ РОБОТ. Я ТВОЙ РАБОТНИК.

[Revok]

I don't have anything to add besides the fact that I really want to see this happen!

[JP]

I was just researching vocoders yesterday. Nearest idea I had was picking up one of the many sub $200 pedal vocoders and converting it so it lived behind a eurorack panel. This project sounds WAY more serious. I'll be following along, and will be tempted as long s it's not crazy complex (is that really 4 stacked PCB's).

[L-1]

It's not crazy complex. All 24 channels are identical except for the caps values. Some trimming required - 3 trimpots for every channel to set levels.
And no 4 but 5 boards, one for controls and in-out circuits.
The project will be quite expensive. I think build cost will be about 500$.
Therefore I plan to release first limited quantity, maybe 10 sets.
This is original one. 5 channels don't work and can't trimm properly because old rusty trimpots.
It is very rare - not more as 100 were produced in 1988, and not many survived until today. My has 25 serial.

[L-1]

His voice (carrier - two square waves (I tweak freq a bit), modulator - sample)

[emdot_ambient]

"Hier spricht die Stimme der Energie"

Very Kraftwerk.

[limpmeat]

looks really interesting, a lot more compact than the haible vocoder

[LoFi Junglist]

Don't forget a filter stack can be used to implement a Barber Pole filter.

It would be great if these boards allow for this option, if the user adds a "Shepard controller" such as the old discontinued(?) Doepfer module (I'll probably be in the market for 16 or 32 filters pretty soon)

[raisinbag]

Cool, so If I am getting this correct it will be a 24 band unit (4 cards with 6 bands on each one) and it will fit in euro! SWEET!
When you say "release" this, do you mean the 5-PCB set? And it uses THAT and 074s and noting super rare, WOW
Well the Sound clip is great, can't wait to see this one come together.

[sanders]

Great demo! That sounds fantastic!

This is really impressive, nice work. I'd be interested, but I couldn't lay out $500 all at once.

I had been thinking recently how the Korg VC10 would make a great DIY Vocoder. It sounds great, and had 22 bands + envs all on one medium-large sized PCB, with preamps, compander, and divide down synth on a second PCB. There was a salvaged filter PCB on ebay not long ago, but I lost the bid. It went for only $75.

I wouldn't be super surprised if this soviet design was derivative of the Korg.

PS-- are you still planning to offer you VC Compressor PCB? I was getting interested in that one also.

[astroschnautzer]

having outputs and inputs for the mic pre, limiter and eq would be useful so one can use those separetly too... or to bypass the vocoder section so you would get a chain for those that would also be useful....

[L-1]

[Altitude909]

This is relevant to my interests.. Been looking for a vocoder project for a while

[Luka]

Nice - would love to get this

[ndkent]

Looks interesting and on a good track. Eventually you'd want to look into voiced/invoiced, but you don't need that to get the vocoder bands all working. Also, while I know you are improving the specs on the Soviet original its worth finding out what the good ones did right.

As for other comments -- $200 pedals? what's analog in that range and in a pedal??

As for the Doepfer Shepard Module. Please fill me in on a Shepard filter?? I have that module. I thought since there's a micro controller inside it had 2 separate modes. The Shepard generator did like 15 LFOs from a master tempo that are all triangles and ramps with different phases. You'd use some of them with gear that has a VC frequency like multiple phasers or VCOs though nothing stops you from opening and closing a vocoder decoder for a sort of smooth fixed bandpass cross fading. Can't do a Shepard effect with a vocoder decoder since you can only open and close fixed bands though you can do a Moogerfooger murf fx. The other Doepfer mode is Midi CC to 0-5v in 15 or whatever channels. So you could connect that and MIDI each band to open and close.

Anyway one thing that can be said us it really opens up options if you have a normalized jack out of each envelope follower and a normalized hack into each VCA

[samuraipizzacat29]

definitely.

[NS4W]

I'd be interested.
The mp3 you posted of the soviet vocoder sounds so good! Please don't make your version too clean and soulless - it's the raw gritty sound that's appealing!

[LoFi Junglist]

[ersatzplanet]

[Popski]

I'd love one of these..