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WIGGLING 'LITE' IN GUEST MODE

WMD Digital VCA !!
MUFF WIGGLER Forum Index -> Eurorack Modules Goto page 1, 2, 3, 4  Next [all]
Author WMD Digital VCA !!
WMDevices
I would like to introduce the WMD Digital VCA. This is a module that I've been working on with Suit & Tie Guy for a few months. STG will be introducing a 5U version of this module that fits 3 VCAs in the next few weeks.

And so..... The WMD/STG Digital VCA incorporates a very short input to output signal path and ultra low noise opamps. The design uses a microcontroller to interpret the control voltage signals and drive the VCA circuit. Yadda yadda, thats all good and normal, but here is the fun part.

The Digital VCA incorporates a Zero Crossing detector which only allows for control voltage changes to happen while the input signal is crossing the ground potential. This allows for the Digital VCA to open instantaneously without annoying pops and clicks on signals up to 15kHz. Good luck hearing a pop at 15kHz.

The design also incorporates Gate mode which only allows for control voltage changes to occur on the rising edge of a gate signal. This lets you use other signals to control the updates of the CV on the Digital VCA predictably. Think of this mode as a sample & hold VCA.

The overall specs are 6 HP, +75 / -45 mA current draw. Ultra low noise opamps and complete closing of the VCA with 0 volts CV. The circuitry can respond to 5V or 8V CV signals and has a linear response. VCA resolution is limited to 8 bits producing a little bit of low-fidelity tone on the control side. Analog signal range is +-10V.

The signal path is purely analog, with an 8 bit resolution control voltage signal path. This is a VERY transparent VCA and coupled with the Zero-Crossing Detector makes it incredibly useful for fast attack/fast release signals. Finally turn your PEG Skew control all the way CW or CCW without the pops.

WMD expects a serious snow day tomorrow and hopes to create a demo video. So stay tuned!

Thank you to STG for posting the post-card teaser (you guys had no idea what the module was, but STG did a great job disguising it!!).

These are in final production/testing NOW and will be shipping by the end of the week to your favorite dealer. Street price for the eurorack version is $179, 5U version TBD.

You can never have enough VCAs, and thanks to a great idea by STG you have an entirely NEW type of VCA available for your system. *Sorry for the shameless ad speak*....But I really think you will enjoy the versatility and sound of this concept.

Edit for video:



Edit: Webpage is now up: WMD Digital VCA

Edit for current draw: +75 / -45 mA

Matos
Thank goodness this mystery is solved. Looking at that pcb just told me that this was most likely an electronic device. Still need to save for the synchrodyne expander first. very frustrating
rjp2
Sounds great, very interested in trying it out applause
suboptimal
Wow! Count me in for sure.
analogPedagog
All I gota say is screaming goo yo screaming goo yo screaming goo yo
kuxaan-sum
Wow...this looks awesome William...

I need to get off the fence on some of your other designs.
Been scared to head down that path...Mr. Green
Low on case space and all but shit I might as well just decide now what I should get first.

BTW: DPS is closed so the snow day is official. thumbs up
HeWhoWantsJeans
Damn - you two are crazy. This sounds like a fantastic concept.
John Noble
Neato!

Do you happen to have a mounting depth spec? Mr. Green

http://eurorackdb.com/node/1667
acidbob
I just bought the mmvca a couple of days ago, now i want this as well very frustrating
protocaps
I was in the market for a 4 hp vca but I think I can stretch it a bit for this. The gate mode is a total deal breaker for me.
waveglider
I love all the forward-thinking going on in WMD modules, really pushing things forward!
suitandtieguy
Mr WMD is very gracious and i look forward to putting this in my own system.

i'm fairly confidant in saying that it is impossible to make a VCA with any less components in the signal path here. if you want clean, this is it (as long as you're ok with 8-bit resolution!)
suthnear
So 8 bit means only 256 possible volume levels. Is this scaled in any way, given that amplitude is logarithmic?
BOB-SNARE
Using an 8-bit DAC like the RNC compressors did?
Sounds like neat idea!
meatbeatz
Keen to hear more about this. The zero crossing detector is the answer to one of my main gripes with the modular. Pops and clicks always shat me. No good syncing an osc if it don't reset at zero volts. WMD continues to pump out the goods. Bring them demos!
haesslich
thumbs up It's peanut butter jelly time! nanners It's peanut butter jelly time!


??
ddoyen
Niiiice! I found my next vca! Rockin' Banana! Rockin' Banana! Rockin' Banana!
Entrainer
Nice. I want one of these for sure.

William- have you tried audio-rate Amplitude Modulation with it?
256 volume positions, zero-crossing = interesting digi-esque FSU
waveshapes?
hanerlend
I was really annoyed earlier today by pops and bleed in my a-132-3. Suddenly WMD digital VCA + Triple Bipolar VCA seems like an interesting combo to put on my "future system" list.

This is linear. Any chance we'll see a logarithmic version in the future? (I notice there is room for a common lin/log switch besides the 5v/8v switch. Mr. Green)

-han
WMDevices
Quote:
BTW: DPS is closed so the snow day is official.


This is one wimpy snow-storm to close all the schools....

Quote:
So 8 bit means only 256 possible volume levels. Is this scaled in any way, given that amplitude is logarithmic?


Yes, only 256 possible amplitude levels. The signal passing through the VCA is NOT digitized, only the control signals. But yes, you will get little stair steps while changing volume levels. That's part of the charm, it's designed to have some *sound* to it.

Quote:
Pops and clicks always shat me. No good syncing an osc if it don't reset at zero volts.


I agree completely. All this talk about *snappy* envelopes causing pops...It's not your envelope.

With this you can just use gates to turn on and off sine-waves with NO popping.

Quote:
William- have you tried audio-rate Amplitude Modulation with it?
256 volume positions, zero-crossing = interesting digi-esque FSU
waveshapes?


I attempted some of this in the demo video I just posted. It does some nice normal AM, and the ZCD tends to smooth it out even more. It also gets glitchy using the Gate mode or ZCD with a fast input signal to the Update jack.

Quote:
This is linear. Any chance we'll see a logarithmic version in the future?


Yes it is linear. AFAIK there isn't a high-voltage (+-12V tolerant), high resolution (8-bit) Digital pot available that would make a good log VCA. If someone makes one I will do a log version for sure. It could be done by attenuating and offsetting to get the range within 0-5 volts and using a low voltage Digi-Pot, but that adds a lot more circuitry. I don't know if there are any 8 bit log pots available even at low voltages.

Also, Video is posted at the top, and the web page is up! Now it's time to start testing!! Thank you all!
Funky40
WoW, genius concept,
but why no Gainoffset and CV attenuator as usual ?
matttech
wow - looks really interesting as usual! thumbs up
zdarma
Excellent video, as usual.
davidh
génial thumbs up

my next VCA
DonKartofflo
alrighty, gonna buy a tbvca and then this thingy will be on the list thumbs up
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