Why is SSL style compression so popular? [general question]

[altfidelity]

New here, thinking of dipping toes in DIYing, otherwise just mechanical engineer/programmer with musical ambitious.

Why are SSL compressor clones prevailing in DIY community?
Is it the availability of components, low cost and ease of building, or is it that compression action is objectively so useful/effective and pleasant sounding in studio use?

Excuse my weird/non-relevant question.

 

[gyraf]

easy to use / get good results from, easy to recognize it's sonic imprint from numerous "big" albums. relatively easy and cheap to build. easy to get tracking in stereo, contrary to most other designs

what's not to like?

/Jakob E.

 

[altfidelity]

Jakob, what an honor. I'm not so much "in" this community, but I recognise that you are basically legend around here.

I was NOT dismissive of SSL (or GSSL) as a whole, its just that every other DIY build (or plugin for that matter) is SSL clone, the other half being LA-2As.

I sort of get it, but the creative side of me (as a engineer) is kinda let down as it feels like there is little place left for improvement and invention. Would you say G(SSL) is basically such an elegant circuit design, that renders others designs redundant/overcomplicated?

an example on GSSL:
Why repeating exact fixed attack/release values SSL chose decades ago, or why not make secondly (Auto) release time accessible on 100ms release setting, or why not make a FET version of it...

I am basically just thinking loud at this point

 

[iampoor1]

Jakob, what an honor. I'm not so much "in" this community, but I recognise that you are basically legend around here.

I was NOT dismissive of SSL (or GSSL) as a whole, its just that every other DIY build (or plugin for that matter) is SSL clone, the other half being LA-2As.

I sort of get it, but the creative side of me (as a engineer) is kinda let down as it feels like there is little place left for improvement and invention. Would you say G(SSL) is basically such an elegant circuit design, that renders others designs redundant/overcomplicated?

an example on GSSL:
Why repeating exact fixed attack/release values SSL chose decades ago, or why not make secondly (Auto) release time accessible on 100ms release setting, or why not make a FET version of it...

I am basically just thinking loud at this point

Because original designs take far more work than most people want to put in. Look around the forums, there are plenty of original designs here.

It's a popular project because it sounds great and is a very useful tool. You can modify it as much as you want, but it's usually a good idea to build a circuit first and then ask "what would I like to be different". The stock attack/release times on the ssl work well for a wide range of styles..but are easy enough to modify!

And the reason why you wouldn't build a fet gssl...is because the circuit is not really the right topology to easily do that. It's a feedforward compressor.

 

[TwentyTrees]

Why repeating exact fixed attack/release values SSL chose decades ago, or why not make secondly (Auto) release time accessible on 100ms release setting, or why not make a FET version of it...

In my view Jakob's point about easy tracking in stereo is particularly significant here. The (G)SSL is designed to be stereo from the ground up, which makes it a relatively easy build for the stereo bus - unlike something like a FET or optical compressor, where you'd have to select & match parts much more carefully.

One additional point I'd offer is that the (G)SSL makes a good platform for modding. My second ever project was a version of PCB Grinder's MS-VECA (basically a GSSL with variable mid/side blend in the side chain), and I built it with a bunch of mods - variable attack and release, 1:1.5 ratio, bunch of side chain filters. That said, I generally use the preset time constants - they're well-chosen.

Is it the be-all and end-all of compressors? No, there's a lot of internet mythology around it, but it is very capable. The design is flexible, predictable, useful, and thousands of people have built them so if you run into trouble or want to do something different then there's a lot of inspiration and material to draw from. There are plenty of other options out there though.

 

[living sounds]

It's all of the above. It's one of the least expensive and easiest to build (minus a few close solder-points you have to watch) designs. And it's a proven design that delivers a signature sound, easy to use, and also very useful beyond stereo / drum bus duties (try it on bass and all kinds of stereo tracks like piano, keyboards, BG vocals etc.).

I've got very nice compressors for the mixbus - vari mu, diode bridge and even Jakob's fabulous G24, but still often choose an SSL for its specific punch and glue.

 

[Ricardus]

Because if it's good enough for Chris Lord Alge, it's good enough for me.

 

[altfidelity]

Thanks for the feedback(feedforward), I was not trying to piss on anyone's parade, just thinking aloud.

OK, let me rephrase my train-of-thought in a more pragmatic question:

Are there are any similar similar designs worth building, derivate of (G)SSL design or not, that are:

-"...designed to be stereo from the ground up..."
-using off the shelf/easy-to-get components (VCA etc).
-beginner-friendly to build
-proven to work
-work in a more RMS/feedback/opto/soft knee/levelling fashion.

Thanks!

​

 

[living sounds]

You might try the JLM Opto Compressor, currently out of stock though, and not as cheap as a GSSL:

https://www.jlmaudio.com/shop/mac-rack-kit.html?display_tax_prices=1

 

[soapfoot]

I sort of get it, but the creative side of me (as a engineer) is kinda let down as it feels like there is little place left for improvement and invention. Would you say G(SSL) is basically such an elegant circuit design, that renders others designs redundant/overcomplicated?

an example on GSSL:
Why repeating exact fixed attack/release values SSL chose decades ago, or why not make secondly (Auto) release time accessible on 100ms release setting, or why not make a FET version of it...

I am basically just thinking loud at this point

There are reasons for this beyond stasis/inertia (or lack of imagination).

The SSL bus compressor is a tool that many in the industry have built workflows and even careers around.

If you purchase or rent a car, you can usually find turn signals, wipers, headlamps, gear changes, etc. quickly.

This isn’t by accident! In some applications “improvements” or “refinements” feel disruptive. If a manufacturer were to decide to optimize or innovate by swapping positions of the accelerator and brake pedals, I don’t think they’d have too many happy customers!

Similarly, when a piece of gear has become foundational to an art form, theoretical “improvements” can sometimes take away from the gestalt of the thing. In the 1980s many people did things like adding active pickups to vintage Fender basses. Hindsight has shown us that something of the essence can get lost in the process, and most have been converted back…

 

[altfidelity]

You might try the JLM Opto Compressor, currently out of stock though, and not as cheap as a GSSL:

https://www.jlmaudio.com/shop/mac-rack-kit.html?display_tax_prices=1

I would prefer a design without vactrols, I have bad experiences using mismatched stereo opto compressor. (ahem, ahem ART VLAii).
I'm sure JLM Opto Compressor is a splendid design though...

Maybe something along what TK AUDIO is doing with their T-KOMP.
VCA, feedback topology, soft-knee, dual program release stage (to mimic some of the slowness of levellers), maybe some transformers on the outputs.
Anything similar in concept in the DIY land?

 

[living sounds]

I would prefer a design without vactrols, I have bad experiences using mismatched stereo opto compressor. (ahem, ahem ART VLAii).
I'm sure JLM Opto Compressor is a splendid design though...

Maybe something along what TK AUDIO is doing with their T-KOMP.
VCA, feedback topology, soft-knee, dual program release stage (to mimic some of the slowness of levellers), maybe some transformers on the outputs.
Anything similar in concept in the DIY land?

Well, you did write "opto". If you're looking for a VCA compressor that sounds like an Opto though...

 

[altfidelity]

There are reasons for this beyond stasis/inertia (or lack of imagination).

The SSL bus compressor is a tool that many in the industry have built workflows and even careers around.

If you purchase or rent a car, you can usually find turn signals, wipers, headlamps, gear changes, etc. quickly.

This isn’t by accident! In some applications “improvements” or “refinements” feel disruptive. If a manufacturer were to decide to optimize or innovate by swapping positions of the accelerator and brake pedals, I don’t think they’d have too many happy customers!

Similarly, when a piece of gear has become foundational to an art form, theoretical “improvements” can sometimes take away from the gestalt of the thing. In the 1980s many people did things like adding active pickups to vintage Fender basses. Hindsight has shown us that something of the essence can get lost in the process, and most have been converted back…

Don't get me wrong. You are probably way more experienced then me, and you opinion is objectively more valid then mine, but...
I thing there is a place for fresh new designs, along LA2A, SSLs, 1176, NEVEs etc., especially in an era where hardware is going extinct basically.
DISTRESSOR is a good example of this, totally fresh new design, that was immediately welcomed in every studio around the world.
We would never have a distressor if Dave Derr kept making 1176 clones.


Some fresh new designs that cough my eye in last few years, that I think are cool and fresh.

BUZZ AUDIO DBC-20
TK AUDIO T-KOMP
Golden Age Project Comp-54
Drawmer 1968 & 1978

Retaining what made older gear good and honoring the roots, staying budget-friendly, while somewhat expending on a original concepts.

​

​

 

[altfidelity]

Well, you did write "opto". If you're looking for a VCA compressor that sounds like an Opto though...

OK, not OPTO then, somewhat program/RMS dependent.

 

[living sounds]

Don't get me wrong. You are probably way more experienced then me, and you opinion is objectively more valid then mine, but...
I thing there is a place for fresh new designs, along LA2A, SSLs, 1176, NEVEs etc., especially in an era where hardware is going extinct basically.
DISTRESSOR is a good example of this, totally fresh new design, that was immediately welcomed in every studio around the world.
We would never have a distressor if Dave Derr kept making 1176 clones.


Some fresh new designs that cough my eye in last few years, that I think are cool and fresh.

BUZZ AUDIO DBC-20
TK AUDIO T-KOMP
Golden Age Project Comp-54
Drawmer 1968 & 1978

Retaining what made older gear good and honoring the roots, staying budget-friendly, while somewhat expending on a original concepts.

​

Fresh new designs?

How many times can you invent the wheel? The only really innovative more recent design I can think of is the Gyraf G24. And even this remarkable unit uses the well-established principle of utilizing opto cells for compression, though with a few brilliant twists.

The Golden Age 54 for instance is just a chinese made clone, more or less, of the vintage Neve diode bridge compressor design.

 

[soapfoot]

Don't get me wrong. You are probably way more experienced then me, and you opinion is objectively more valid then mine, but...
I thing there is a place for fresh new designs, along LA2A, SSLs, 1176, NEVEs etc., especially in an era where hardware is going extinct basically.
DISTRESSOR is a good example of this, totally fresh new design, that was immediately welcomed in every studio around the world.
We would never have a distressor if Dave Derr kept making 1176 clones.


Some fresh new designs that cough my eye in last few years, that I think are cool and fresh.

BUZZ AUDIO DBC-20
TK AUDIO T-KOMP
Golden Age Project Comp-54
Drawmer 1968 & 1978

Retaining what made older gear good and honoring the roots, staying budget-friendly, while somewhat expending on a original concepts.

I don't disagree with the premise, necessarily!

Just pointing out that there are a range of valid motives, and there are sensible reasons for a good design to endure unchanged. There's room for all, really.

I'd just guard against expecting a tinkering-about-the-margins to take the world by storm when an existing technology isn't broken, has already achieved wide acceptance and has proven itself over decades.

We see an interesting example of this journey with the electric guitar. The mid-1960s through early 1990s saw all manner of refinements--low impedance pickup systems, active pickups and preamps, locking vibrato systems, sustain-enhancing bridges, hum-canceling single coils, locking tuners, roller nuts, flexible switching systems, piezo saddle integration, graphite necks and saddles, carbon fiber exoskeletons...

And by the late 1990s nearly everyone had reverted to a fairly-narrow range of mature technologies from the 1950s and early 1960s. Some of those later refinements have hung on in limited or niche capacities, but as the guitar has become more classicized most have fallen out of the mainstream. This hints that a good many were either "solutions in search of a problem" or presented additional complications that hindsight revealed to outweigh their benefits.

In reality, when tweaking a successful, enduring design this is by far the most-likely result.

 

[JohnRoberts]

compressors are a mature technology do you have any specific target goals?

JR

 

[wlinart]

Don't get me wrong. You are probably way more experienced then me, and you opinion is objectively more valid then mine, but...
I thing there is a place for fresh new designs, along LA2A, SSLs, 1176, NEVEs etc., especially in an era where hardware is going extinct basically.
DISTRESSOR is a good example of this, totally fresh new design, that was immediately welcomed in every studio around the world.
We would never have a distressor if Dave Derr kept making 1176 clones.


Some fresh new designs that cough my eye in last few years, that I think are cool and fresh.

BUZZ AUDIO DBC-20
TK AUDIO T-KOMP
Golden Age Project Comp-54
Drawmer 1968 & 1978

Retaining what made older gear good and honoring the roots, staying budget-friendly, while somewhat expending on a original concepts.

​

​

No one is stopping you from designing something cool and fresh...
GSSL is nice, and loads of people here use it as one of their first projects, because it's cheap, easy and great sounding. After that, some people start learning more (because it's so addictive) and design something fresh.

 

[JMan]

I would say that Heikki is a great example of someone who designs new and interesting things (though…did he recently leave?). Maybe they aren’t technologically groundbreaking, since as John said, compressors are a mature technology, but they are certainly somewhat unique designs and not clones of existing gear. That said, I don’t see anything wrong with building common, known circuits like the Gssl (and its myriad variants). It is easy to think, especially when first dipping your toe in, that some highly esoteric circuit design that breaks all the conventional assumptions is going to provide the magic secret sauce, but in truth that is very unlikely, and you will probably have your best results with the standard smattering of units that everybody else has built and uses. But of course, if you design something new and unique, I am also sure that everyone here will be excited for it!

 

[living sounds]

I would say that Heikki is a great example of someone who designs new and interesting things (though…did he recently leave?). Maybe they aren’t technologically groundbreaking, since as John said, compressors are a mature technology, but they are certainly somewhat unique designs and not clones of existing gear. That said, I don’t see anything wrong with building common, known circuits like the Gssl (and its myriad variants). It is easy to think, especially when first dipping your toe in, that some highly esoteric circuit design that breaks all the conventional assumptions is going to provide the magic secret sauce, but in truth that is very unlikely, and you will probably have your best results with the standard smattering of units that everybody else has built and uses. But of course, if you design something new and unique, I am also sure that everyone here will be excited for it!

I would have recommended Heikki's Vari-Mu compressor since it sounds great, is reasonably simple and inexpensive. But it's not really ideally suited for beginners with high voltage, tubes (needing calibration, too) and quite a lot of wiring. The GSSL is really as simple and cheap as possible for a high end stereo compressor.