SSL (Or Similar) Console Saturator/Distortion

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cpsmusic

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Hi All,

I'd like to make a simple saturator/distortion processor for use in my small home studio. I recently came across this one:

HITMAKER 4000 80's E-Series Console Colour

which is supposed to emulate the sound of an SSL E Series console. This is the sort of thing I'm after - some gentle 2nd/3rd-order harmonic generation, but not too much.

Unfortunately there's no schematic, and as the device looks very simple, I was wondering if anyone here had any ideas, schematics, etc. that might help with putting together something like this?

Cheers,

Chris
 

andow

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Why don't you build a GSSL compressor? 😉
It's a pretty simple and well documented project that's also not very expensive...
If you drive it you'll get the same effect plus you'll have a very nice sounding compressor!
 

cpsmusic

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Why don't you build a GSSL compressor? 😉
It's a pretty simple and well documented project that's also not very expensive...
If you drive it you'll get the same effect plus you'll have a very nice sounding compressor!
Won't this produce something quite different in terms of sound? BTW, I already have a couple of good compressors.
 

andow

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As far as I can tell this module is more or less the signal path of the SSL buss compressor, so I would assume the sound is similar.
But if you don't need another compressor I can see that a GSSL is overkill. You could just build the signal path without the sidechain which would make it a lot simpler...
 
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john12ax7

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Look at the schematics for a 4000 mix bus amp. The device referenced is basically using that. There are unseen parts on the bottom of the pcb so it may look simpler than it is from just the top side.
 

abbey road d enfer

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HITMAKER 4000 80's E-Series Console Colour

which is supposed to emulate the sound of an SSL E Series console. This is the sort of thing I'm after - some gentle 2nd/3rd-order harmonic generation, but not too much.

Unfortunately there's no schematic, and as the device looks very simple, I was wondering if anyone here had any ideas, schematics, etc. that might help with putting together something like this?
Apparently it's just the VCA stage of a 4K + a HF shelf EQ. You could just use the application schemo for the THAT2180. You don't need the EQ if you have a mixer or a DAW.
 

cpsmusic

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Look at the schematics for a 4000 mix bus amp. The device referenced is basically using that. There are unseen parts on the bottom of the pcb so it may look simpler than it is from just the top side.
Yes, I was having a look at the picture of the device and the capacitor numbering suggests there's quite a bit going on on the underside of the board.
 

cpsmusic

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Look at the schematics for a 4000 mix bus amp. The device referenced is basically using that. There are unseen parts on the bottom of the pcb so it may look simpler than it is from just the top side.

Is the attached what you're referring to?

Also, I'm at the early-intermediate level electronics-wise so designing something like this is a bit beyond me. The problem I keep running in to is that most of the info I've found regarding opamps is either how to reduce distortion (from the manufacturers) or how to generate a lot (guitar pedal makers). There doesn't seem to be much in between - anyway, that's my whinge-of-the-day 😣

Also, this thread

variable harmonic drive discussion

discusses the sort of thing I'm interested in but unfortunately it looks like it never progressed beyond this point.

Cheers,

Chris
 

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john12ax7

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I don't know the original schematics off hand, but that looks probably correct. Then there is probably a VCA that follows.

If you are looking for something simpler perhaps experiment with driving some transformers. That can be an easy way to get some harmonic distortion.
 

abbey road d enfer

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Is the attached what you're referring to?
This is the bus summing amp, that is designed for ultra low distortion, as is most of the signal path in the 4k. Actually, when it came out, the 4k was famous for having an almost non-existent sonic signature. Neutrality was an avowed aim of Colin Sanders.
The only parts that could confer any kind of "mojo" (read dirt) were the xfmr in the mic input, and the VCA.
 

cpsmusic

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This is the bus summing amp, that is designed for ultra low distortion, as is most of the signal path in the 4k. Actually, when it came out, the 4k was famous for having an almost non-existent sonic signature. Neutrality was an avowed aim of Colin Sanders.
The only parts that could confer any kind of "mojo" (read dirt) were the xfmr in the mic input, and the VCA.

Right, so what I need to look for is the VCA? Any chance of a link to the appropriate schematic as the modular nature of these consoles means that I don't really know what I'm looking for amongst all the various schematics that are available.
 

abbey road d enfer

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Here it is. The VCA is part of the dynamics section.
The THAT2151 is not available anymore, but can be replaced with the 2180. No need to take the expensive "A" version, the "C" version has more mojo (read distortion). The symmetry adjustment will not work with teh 2180.
You could use the 2181, and deliberately offset the symmetry adjustment for more mojo (read crap).
 

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cpsmusic

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Thanks. In order to increase my limited understanding of how these things work I was having a look here:

VCAs

It's interesting to note that the author says "The distortion is interesting. Unlike most circuitry, distortion is limited to second and third harmonics, with almost nothing beyond that". Of course, the distortion level is probably quite low, and the idea of trying to increase it is an anathema to many!
 

cpsmusic

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Something I forgot about is that the latest SSL USB interfaces have a "4K" button which apparently add subtle harmonic distortion. These units are relatively inexpensive - just wondering if anyone has taken the lid off one of these to see what's going on?
 

TheJames

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For me, the "sound" of the SSL is by far in the bus compressor. Once you turn that thing on you start to hear that sound you've heard a billion times before. This was so much the case that upon experiencing it first-hand, I spent the time and effort making the SB4000 bus compressor and did the parallel VCA board on it. It's a treasured piece in my kit and I wouldn't mind having another.

I've seen people discuss the channel VCA's (for automation) on the 4K's as having some sonic imprint, but that was greatly reduced by the time the 9K's rolled around. I seem to recall accounts of engineers avoiding these VCA's because of the detrimental impact they had on the sound.

The other thing that I see mentioned alot is the "EQ" and having the "right" EQ in your old 4K makes it more desirable. I think of the SSL EQ of more generally functional than magical, but I can't really say as I've only directly experienced a 9000 and a 6000. Neither of them really made me go "wow" when I used the EQ. The Cranesong Ibis however was stunning.

Perhaps it's best to understand that the SSL was intended to be a really neutral board and what really made the board such a huge success was it's functionality and not so much its sound. Once upon a time, SSL boards were mocked as the name standing for "Sounds So Little." Our very own Jeff Steiger of CAPI has shared the story of his console search where he went and checked out an SSL and after hearing it, was underwhelmed. If I recall correctly. it was exactly this experience that drove him away from SSL and into buying an older API console and ultimately starting up CAPI.

So I dunno...If you went through the entire signal path of an SSL 4K with all of it's features, you'd be hitting dozens of 5531/5532 opamps, a slew of coupling caps, and a handful of VCA's. I don't think you can effectively emulate that with a simple module and gain much impact.
 

cpsmusic

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For me, the "sound" of the SSL is by far in the bus compressor. Once you turn that thing on you start to hear that sound you've heard a billion times before. This was so much the case that upon experiencing it first-hand, I spent the time and effort making the SB4000 bus compressor and did the parallel VCA board on it. It's a treasured piece in my kit and I wouldn't mind having another.

I've seen people discuss the channel VCA's (for automation) on the 4K's as having some sonic imprint, but that was greatly reduced by the time the 9K's rolled around. I seem to recall accounts of engineers avoiding these VCA's because of the detrimental impact they had on the sound.

The other thing that I see mentioned alot is the "EQ" and having the "right" EQ in your old 4K makes it more desirable. I think of the SSL EQ of more generally functional than magical, but I can't really say as I've only directly experienced a 9000 and a 6000. Neither of them really made me go "wow" when I used the EQ. The Cranesong Ibis however was stunning.

Perhaps it's best to understand that the SSL was intended to be a really neutral board and what really made the board such a huge success was it's functionality and not so much its sound. Once upon a time, SSL boards were mocked as the name standing for "Sounds So Little." Our very own Jeff Steiger of CAPI has shared the story of his console search where he went and checked out an SSL and after hearing it, was underwhelmed. If I recall correctly. it was exactly this experience that drove him away from SSL and into buying an older API console and ultimately starting up CAPI.

So I dunno...If you went through the entire signal path of an SSL 4K with all of it's features, you'd be hitting dozens of 5531/5532 opamps, a slew of coupling caps, and a handful of VCA's. I don't think you can effectively emulate that with a simple module and gain much impact.

Thanks for the info. I'm well aware that SSL consoles are known for being sonically "neutral", especially the 9000 series and later. I'm actually more interested in being able to produce gentle 2nd/3rd-order harmonics and it just so happens that my searches have led me to the early SSL designs. But if there's other alternatives then I'm happy to look at them.
 

mushy

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I have noticed when using my passive summer and using my diy SSL9k pres for makeup gain I get the top end distortion excitement that I used to get from a console.
 

SWAN808

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There was some speculation around the SSL Variable harmonic drive circuit but no firm answers...the SSL driven sound I suspect is a result as mentioned above, many Op amp stanges and a couple of transformers...I've tried driving a NE5532 and the results arent nice - I think you need to push a whole raft of them to get that squeezed punchy sound...I'd be interested if others could shed any light on it...
 

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