Let's talk VCAs - What makes a good one?

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apcuddling
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Let's talk VCAs - What makes a good one?

Post by apcuddling » Fri May 22, 2020 11:29 pm

Hey gang!

I wanted to get some feedback on this - What makes a good VCA? Or rather, what sets one apart from another aside from the additional features like lin/exp curve control, normalized channels, gain saturation, etc.

Maybe I'm missing something, or maybe my ear isn't as trained as well as others out there, but to me it's seeming like VCAs are all the same not just by their basic function or purpose, but also by performance. Obviously I haven't demo'd EVERY single VCA out there, but I've tried a few and the results seem to be the same - which can be great sometimes because it's nice to have things work exactly as expected but with all of these flavors and colors available with VCFs and VCOs and such, I wonder if this also exists with VCAs and I just haven't seen it yet.

For example, is there any sort of performance difference between say Intellijel's Dual VCA and XAOC's Tallin? Obviously there is a difference in features, but what are the major underlying factors that set one apart from others?

I feel like companies are still putting out VCAs and sometimes I wonder why. Is it a matter of rounding out their full product line, or is there really a noticeable difference with innovative design or circuitry?

Hoping someone can enlighten me on this. Where's my VCA connoisseurs?

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Re: Let's talk VCAs - What makes a good one?

Post by Shledge » Fri May 22, 2020 11:37 pm

Depends on your needs, I guess.

For me, it's the ability to amplify beyond the normal signal and to have a clear, noise free output. Bias is quite nice too, along with lin/exp controls.

If there are multiple VCAs on a module, I would expect to have an option for both individual and mixed outputs.

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Re: Let's talk VCAs - What makes a good one?

Post by daphnid » Fri May 22, 2020 11:40 pm

A lot of the difference is the character when driven. Most of them overdrive in an intentional/specific way. Which one is better is completely subjective at that point. Also some are meant to be more feature packed, others more compact. There are digital "clickless" options, lo-fi VCAs, etc.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Fri May 22, 2020 11:47 pm

Right. Well those are what I meant by additional features.
So...if we compare to VCFs there are loads with the same functionality (frequency, resonance, LP out, HP out, etc.), but they can sound completely different on how they handle the incoming signal. I guess I'm wondering if there is something like that with VCAs?
To go off of your preference of a noise free output on a VCA - There are some people who like the WASP filter for it's gritty characteristics, is there something like a gnarly mangly VCA that offers up a similar purpose in that arena?

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Fri May 22, 2020 11:54 pm

daphnid,

This is more in the direction of what I'm looking for.
Can you give some examples of VCAs that are specifically liked for their lo-fi characteristics?
And I get it's all subjective, but there also exists a degree of fact about how and why one VCA performs entirely different from another.
I suppose I should have specified that I'm not approaching this from a position of, "I'm looking to get a VCA, which one should I get". I'm just trying to get a better understanding of the differences outside of additional features, no matter how useful they can be.

Thanks!

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Re: Let's talk VCAs - What makes a good one?

Post by daphnid » Sat May 23, 2020 1:13 am

I haven't used it but the Bastl Skis is an envelope/VCA combo that has a lofi character. I've been curious about that one. Vactrol based VCAs can be considered lofi, they roll off highs and kind of slew the incoming CV signal. I use the LxD as a VCA a lot for this purpose to tame harsh digital signals.

I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA. The Tallin sounds nice in this regard from what I've heard, as do the Erica VCAs. Like VCFs, it's all just very personal. The differences between VCAs are not as extreme as the differences between filters though. Filter topology varies greatly despite having the default controls (cutoff/resonance) conserved between them

Question to others, anyone use the Addac Quintet Mixing Console? Thinking of replacing the Intellijel with it.

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Re: Let's talk VCAs - What makes a good one?

Post by lisa » Sat May 23, 2020 1:47 am

apcuddling wrote:
Fri May 22, 2020 11:54 pm
Can you give some examples of VCAs that are specifically liked for their lo-fi characteristics?
And I get it's all subjective, but there also exists a degree of fact about how and why one VCA performs entirely different from another.
Check out Metasonix RK2 for something different. It is tube based which makes it slightly erratic and it distorts (a lot) in a way that you won’t find in non-tube VCAs.
My first modular track where I used drum modules! There's also a ton of FM cross modulation from the Instruō Cš-L in there and the Metasonix R56 is a big part of the sound. :star:



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Re: Let's talk VCAs - What makes a good one?

Post by architexture » Sat May 23, 2020 1:50 am

Either the specific color, or lack thereof (transparency), snappiness, available range.

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Re: Let's talk VCAs - What makes a good one?

Post by muleskinner » Sat May 23, 2020 2:05 am

daphnid wrote:
Sat May 23, 2020 1:13 am
I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA.
I actually really like the sound of it when pushed! It does seem a bit binary though, there's not much of an 'yellow/orange zone' if you know what I mean.
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Re: Let's talk VCAs - What makes a good one?

Post by daphnid » Sat May 23, 2020 2:39 am

muleskinner wrote:
Sat May 23, 2020 2:05 am
daphnid wrote:
Sat May 23, 2020 1:13 am
I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA.
I actually really like the sound of it when pushed! It does seem a bit binary though, there's not much of an 'yellow/orange zone' if you know what I mean.
Yeah it usually goes straight to crunch/breakup, although the density of the breakup increases as you turn up the gain. Not much tonal range though. I don't hate it. Sometimes it gives a nice guitar amp vibe.

I guess I'm just always hoping for some warm, smooth overdrive but there are modules dedicated to that I suppose. I've always done my distorion/OD with gain staging abuse though, I don't have any dedicated distortions anywhere in my studio.

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Re: Let's talk VCAs - What makes a good one?

Post by Voltcontrol » Sat May 23, 2020 2:42 am

This is more than a VCA, but my favorite one by a mile. It's the integrated combination of features that makes the resulting sonic capabilities stand out. It's layout is ace too.

Image
"The Amplitude & Tone controller is a totally discrete VCA with simultaneous exponential and linear CV input. It also contains an all discrete, Vactrol based VCF with diode limited resonance. It also has a discrete input gain stage. Careful balancing of the input gain and resonance control sets the mix of self oscillation and input signal, distorted on the VCA input if desired. There are no ICs in the signal path."

Otherwise I find quad VCA's quite useful. No particular preference for a specific model as long as they have the characteristics that Shledge pointed out.

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Re: Let's talk VCAs - What makes a good one?

Post by Umcorps » Sat May 23, 2020 3:10 am

apcuddling wrote:
Fri May 22, 2020 11:29 pm

Maybe I'm missing something, or maybe my ear isn't as trained as well as others out there, but to me it's seeming like VCAs are all the same not just by their basic function or purpose, but also by performance. Obviously I haven't demo'd EVERY single VCA out there, but I've tried a few and the results seem to be the same - which can be great sometimes because it's nice to have things work exactly as expected but with all of these flavors and colors available with VCFs and VCOs and such, I wonder if this also exists with VCAs and I just haven't seen it yet.
I think the problem arises because VCA is a misleading acronym. I think there are two kinds of VCA.

The most common variety is really a Voltage Controlled ATTENUATOR. They only turn stuff down. So you'd expect/hope most of these would be sonically transparent.

The ones that really can apply some gain - true Voltage Controlled Amplifiers - are the ones that bring more sonic variety.

And the worst of either sort are the ones that bleed :bang:

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Re: Let's talk VCAs - What makes a good one?

Post by sir stony » Sat May 23, 2020 3:44 am

muleskinner wrote:
Sat May 23, 2020 2:05 am
daphnid wrote:
Sat May 23, 2020 1:13 am
I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA.
I actually really like the sound of it when pushed! It does seem a bit binary though, there's not much of an 'yellow/orange zone' if you know what I mean.
Indeed, that zone between unremarkable and audible overdrive can be fiddly to dial in if you don't want it to distort much. But the overall set of features makes it a valuable tool, particularly that to blend the response curve is what makes the quad VCA earn its keep with me.
The Tallin is a great VCA, too. Very easy to handle, can go from inconspicuously clean to croaking overdrive, especially with the switches flicked. Clearly the most versatile VCA I have.
Then, I have the MST dual 2164. It is simple, sounds fine and clean with linear response, but can create a huge boost and distortion with exponential.
My no-worry go-to VCA is however the River Crux, of which I have three. It doesn't boost or clip, it'll just open up to unity gain and not beyond, a classic attenuator. But it isn't sterile sounding, either. It is a warm and full sounding, retro inspired discrete design realized with modern parts, and the fact it won't overshoot even with exponential response makes it superbly snappy for percussive stuff, it's like the sweet spot dialed in right out of the box, because there is nothing to dial at all, or in other words: no gain, no pain... :lol:
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Re: Let's talk VCAs - What makes a good one?

Post by StrangeAttraction » Sat May 23, 2020 6:52 am

TG4 is an awesome sound improver, not a fantastic VCA. I regret selling mine.
In general, I divide VCA into characterful (L-1 Tube VCA for example, TG4, etc.) and functional VCAs which are all about CV control of the signal strength. Worth having both at hand, really.

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Re: Let's talk VCAs - What makes a good one?

Post by Crashlander42 » Sat May 23, 2020 10:31 am

I quietly started using OPA1678 in the my Hexagram builds a while back. I've never done any measurements to see if there's a quantifiable differences, but I've got to imagine it's a better end product that the ol' tl072.

https://www.etsy.com/listing/644636705/ ... -6xvca-mix

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Re: Let's talk VCAs - What makes a good one?

Post by Stoneyards » Sat May 23, 2020 1:01 pm

So if the intellijel quad VCAs is the prototypical "functional" VCA, is there a standard colorful one? Like the vca equivalent of the cheap and cheerful bastyl cinnamon? I wasn’t aware of the L-1 or the TG4 - but they’re not cheap if you need more than one.

One plus is the L-1 is a Ken stone design, so could be done diy very reasonably...

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 1:59 pm

daphnid wrote:
Sat May 23, 2020 1:13 am
I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA.
I have the Intellijel Dual VCA and kinda have the same feelings about it. Tonally I think it feels a bit rigid and harsh when pushed too much.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 2:05 pm

lisa wrote:
Sat May 23, 2020 1:47 am
apcuddling wrote:
Fri May 22, 2020 11:54 pm
Can you give some examples of VCAs that are specifically liked for their lo-fi characteristics?
And I get it's all subjective, but there also exists a degree of fact about how and why one VCA performs entirely different from another.
Check out Metasonix RK2 for something different. It is tube based which makes it slightly erratic and it distorts (a lot) in a way that you won’t find in non-tube VCAs.
Hmm. I wonder what the noise floor is on a module like that. I've definitely been interested in checking some of the tube modules on the market. Coming from a recording background, I imagine it could be fun and interesting to experiment with using a module like this as a preamp. Thanks for the suggestion.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 2:21 pm

Voltcontrol wrote:
Sat May 23, 2020 2:42 am
This is more than a VCA, but my favorite one by a mile. It's the integrated combination of features that makes the resulting sonic capabilities stand out. It's layout is ace too.

Image
"The Amplitude & Tone controller is a totally discrete VCA with simultaneous exponential and linear CV input. It also contains an all discrete, Vactrol based VCF with diode limited resonance. It also has a discrete input gain stage. Careful balancing of the input gain and resonance control sets the mix of self oscillation and input signal, distorted on the VCA input if desired. There are no ICs in the signal path."

Otherwise I find quad VCA's quite useful. No particular preference for a specific model as long as they have the characteristics that Shledge pointed out.
Ugh. Unfortunately I haven't had the pleasure of sitting down with any Verbos modules. Beautiful designs and they seem to sound great from demos I've watched online.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 2:23 pm

Umcorps wrote:
Sat May 23, 2020 3:10 am
apcuddling wrote:
Fri May 22, 2020 11:29 pm

Maybe I'm missing something, or maybe my ear isn't as trained as well as others out there, but to me it's seeming like VCAs are all the same not just by their basic function or purpose, but also by performance. Obviously I haven't demo'd EVERY single VCA out there, but I've tried a few and the results seem to be the same - which can be great sometimes because it's nice to have things work exactly as expected but with all of these flavors and colors available with VCFs and VCOs and such, I wonder if this also exists with VCAs and I just haven't seen it yet.
I think the problem arises because VCA is a misleading acronym. I think there are two kinds of VCA.

The most common variety is really a Voltage Controlled ATTENUATOR. They only turn stuff down. So you'd expect/hope most of these would be sonically transparent.

The ones that really can apply some gain - true Voltage Controlled Amplifiers - are the ones that bring more sonic variety.

And the worst of either sort are the ones that bleed :bang:
Ah! Good points. It's like vanilla VCAs and then vanilla VCAs with chocolate on top.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 2:27 pm

sir stony wrote:
Sat May 23, 2020 3:44 am
muleskinner wrote:
Sat May 23, 2020 2:05 am
daphnid wrote:
Sat May 23, 2020 1:13 am
I have the ubiquitous Intellijel Quad VCA which clips pretty easily and goes into downright distortion when fully pushed. I don't love the sound of it though, personally, but it's a well designed, workhorse VCA.
I actually really like the sound of it when pushed! It does seem a bit binary though, there's not much of an 'yellow/orange zone' if you know what I mean.
My no-worry go-to VCA is however the River Crux, of which I have three. It doesn't boost or clip, it'll just open up to unity gain and not beyond, a classic attenuator. But it isn't sterile sounding, either. It is a warm and full sounding, retro inspired discrete design realized with modern parts, and the fact it won't overshoot even with exponential response makes it superbly snappy for percussive stuff, it's like the sweet spot dialed in right out of the box, because there is nothing to dial at all, or in other words: no gain, no pain... :lol:
Mmm. Crux sounds right up my alley. Decently priced as a kit too. Thanks for sharing.

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Re: Let's talk VCAs - What makes a good one?

Post by apcuddling » Sat May 23, 2020 2:30 pm

Stoneyards wrote:
Sat May 23, 2020 1:01 pm
So if the intellijel quad VCAs is the prototypical "functional" VCA, is there a standard colorful one? Like the vca equivalent of the cheap and cheerful bastyl cinnamon? I wasn’t aware of the L-1 or the TG4 - but they’re not cheap if you need more than one.

One plus is the L-1 is a Ken stone design, so could be done diy very reasonably...
This is kind of what I was getting at with my original post.
Like, you can hear significant differences with LPGs across the board, but I never hear much in the way of VCAs.
This reminds me, I need to order another Takaab LPG.

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Re: Let's talk VCAs - What makes a good one?

Post by muleskinner » Sat May 23, 2020 4:13 pm

Stoneyards wrote:
Sat May 23, 2020 1:01 pm
So if the intellijel quad VCAs is the prototypical "functional" VCA, is there a standard colorful one?
I always thought Tallinn pretty much fitted that bill.
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Re: Let's talk VCAs - What makes a good one?

Post by Chaklack » Sat May 23, 2020 5:02 pm

muleskinner wrote:
Sat May 23, 2020 4:13 pm
Stoneyards wrote:
Sat May 23, 2020 1:01 pm
So if the intellijel quad VCAs is the prototypical "functional" VCA, is there a standard colorful one?
I always thought Tallinn pretty much fitted that bill.
Tallin certainly does fit the bill. It's quick, it's slow, it's clean, it's dirty - so flexible.

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Re: Let's talk VCAs - What makes a good one?

Post by hawkfuzz » Sat May 23, 2020 5:08 pm

There's not a lot of diversity to changing amplitude. It's not a compressor or filter. Just a way to increase and decrease amplitude. Distortion modules exist that have VCAs as well so they'll have character. The Casper Waver has VCAs and distortions. Is that what you mean?

A lot of VCAs are using the same chip so they function the same but you're comparing them to things that have a lot more circuitry that allows for more diversity. The comparison in my opinion doesn't really work...or maybe I'm misunderstanding.
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