What features are a must have on the GSSL?

There are a couple of builds that are available for the GSSL, but I am hesitant to buy due to the lack of certain features.

I am not a big fan on adding features once I have built a unit and racked it up so I would prefer to have a finished unit and be done with it.

Is the Crush or Blend feature important?

I have never used a GSSL or any of the features mentioned so feedback from those who have will be great in helping me decide.

Thanks.

canidoit said:

Is the Crush or Blend feature important?

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See the other gssl thread.  the CnB is just a parallel compression device.  crush it with the gssl and blend in uncompressed signal.

The only add on board that is an absolute must is the turbo, imo, as it makes it behave like a real dual sidechain buss comp.  But the CnB is pretty cool for parallel compression duties so you don't have to use up extra subgroups on your console.

That crush'n'blend is a stupid and unnecessarily confusing name. It's pure marketing lingo, and oddly enough originated in this DIY community.

It's nothing but a mix knob. dry and wet.

Hahaha yeah. Keith was just having fun back then and the name stuck. Gets everybody
confused who crops up and finds it. (I thought it makes some kinda sound on its own,
like, extra crunch or something).

Funny how a heehaw joke turns into a going name like that - I bet there's a lot of products
that get that destiny.

It's amazing methinks how my perspective has changed since I was first here. The "wow sexy
superopto voodoo compressor" has turned into "two vactrols and an opamp big deal".

In German we say "die kochen auch nur mit Wasser" ("they too only have water to cook with").

Kingston, you can call it 'marketing lingo' if you want, but the term/expression is certainly not stupid.

I've built one compressor with CnB and switchable mono/stereo side chain. It's the most versatile I have.

The C/R/C is a must-have, but it's not really a 'feature'; it's just there to make the hum disappear.

The 'Turbo' is a switchable sidechain... It's probably the single most effective option in terms of controlling how the unit compresses. -See the YouTube video demonstrating how it changes the center-bias dramatically.

If you DON'T have the turbo, you will probably find a sidechain filter important, since the center-bias of the unmodified GSSL means that the kick drum, bass etc. have too much influence... the sidechain filter 'neuters' their low end, in what was an early attempt to address this problem. -If you just want to have LOTS of options, I'd suggest having turbo AND SCF, but if it's one-or-the-other that you want instead of "option overload", I'd go for the turbo... but listen to other people; I'm biased!

The Crush-and blend was conceived to be EXTERNAL... an entirely separate device, so you could try using it with ANY compressor; not just the GSSL... hence the name (which was a jokey name, by the way!) -You crush with whatever you want, then blend however you want... My personal preference is to build one externally. That way you can use it with so much more...

Keith

For me, the turbo turned it from someing I don't use into somethjing that I do. And it's very simple to add.

The C/R/C is a must-have, but it's not really a 'feature'; it's just there to make the hum disappear.

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I think I missed that discussion completely! I don't recall having any hum problems, but I probably haven't used it on really quiet sources.

SSLtech said:

The C/R/C is a must-have, but it's not really a 'feature'; it's just there to make the hum disappear.

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I hear people say this, but I have never had hum in any gssl I have built - not even the slightest bit.  
Although I use my own component values for all electrolytics, psu and audio path (much much larger is some places), as well as massive amounts of psu decoupling added on the back of the pcb, along with a couple other changes...so maybe that has something to do with it.
I'm also very meticulous about my grounding schemes.

regularjohn said:

I hear people say this, but I have never had hum in any gssl I have built - not even the slightest bit.

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Some people here actually measure their equipment. The hum without an alternate PSU or the CRC board is low, somewhere down maybe -60dBu. You rarely - if ever - bump into it in studio use. Crap commercial gear actually leaves factory like that and I suspect people are quite used to it, or even completely unaware of it.

It's still an error. Nasty and completely unnecessary spike in an FFT display. Or measure as extra RMS noise voltage with a decent multimeter. Start chaining equipment like that, especially compressors (gain increase), and you have a real world problem.

Often people here on the forum ask how the noise in a particular project turned out and most often the answer is "I don't hear a thing, just dead silence". Then later it turns out this "dead silent" was actually something quite atrocious like -50dBu when they start chaining stuff.

It's so easy to measure this with your sound card and a free FFT tool like RMAA that I'm surprised how few people actually do it.

Kingston said:

Some people here actually measure their equipment.

It's so easy to measure this with your sound card and a free FFT tool like RMAA that I'm surprised how few people actually do it.

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No need to be snarky.  And yes, I test my gear quite extensively.
I also highly modify everything I build different from the standard BOM to suit my own sonic desires - noise floor included.

BTW, those of us with analog studios have no use for free software.

regularjohn said:

I also highly modify everything I build different from the standard BOM to suit my own sonic desires - noise floor included.

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But BOM doesn't enter the equation as it's not possible to fix this with simple parts replacements. This is a problem with physical traces of the PSU area. The noise is polluted to the board from the VAC connectors next to the rectifier, and because the onboard filter cap + rectifier traces let some of this noise through. CRC board ensures this is cleaned before it ever enters the board.

G9 has a similar problem with B+ bridge rectifier polluting the whole of PCB ground with 100hz and harmonics, again with bad physical placement.

Personally (and this is just for me so please don't shoot me - obviously there are plenty who will disagree), a blend knob for me is completely useless.  I like to process my compressed and clean tracks differently.

ie: maybe my kick needs a little low end cut on my compressed track but it's just right on the clean, etc.

Can't do any sort of seperate processing with a blend knob, the wet/dry are locked into each other.

to me it's like a tv channels more you have less you watch

i built more than 10 differents gssl,  for me my friend and to have better and beter again but never without turbo---------- so turbo is the must.

i tried with dbx202 and with that, conclusion i prefer the vca dbx202 in all case but never tried the dbx substitute form igor.

CRC depending your psu transformer , your diode bridge your regulater and your option, some time you need it some time don't.

External sidechain just in two unit for friends who want to use for drum and bass

Super sidechain too but never used it for my part

Mix ( C&B ) i think a very good way to make it more versatile some times

In order of importance... (IMHO)

- Turbo Board (on switch)
- Trimmer for calibration
- Super Side Chain Filter x2
- Turbo only (no switch)
- Transformer IN/OUT
- CRC
- Hardwire bypass
- Meter board (input/output)

There are endless possibilities.... DIY is very creative and everybody builds it to their own spec and taste

My advice, build it stock with at least the turbo mod hardwired. Then you'd have a nice compressor that is very close to the original.

My vote:
GSSL + Turbo (no switch)

If you like it, you could always build a second one with other options

J

Turbo, thumbs up.
Original GSSL with high pass, thumbs up.
Crush and blend, thumbs up.
Therefore, build two GSSL, one turbo hard wired and the second original with high pass.
Thanks Kieth!  SSLtech double thumbs up!

I really like the high pass filter I added to mine with the turbo board.  I originally wasn't going to add it but am very glad that I did.  I didn't use the SSC board, so I don't know about the Thru*t modes, but I'd highly recommend some sort of switchable high pass.  It really opens up the sound for compressing bass heavy mixes.  It is subtle, but very nice.

A simple resistor/capacitor passive filter set is what I used in mine.  I can send a schematic if you are interested.  Very simple.

spica said:

I really like the high pass filter I added to mine with the turbo board.  I originally wasn't going to add it but am very glad that I did.  I didn't use the SSC board, so I don't know about the Thru*t modes, but I'd highly recommend some sort of switchable high pass.  It really opens up the sound for compressing bass heavy mixes.  It is subtle, but very nice.

A simple resistor/capacitor passive filter set is what I used in mine.  I can send a schematic if you are interested.  Very simple.

Click to expand...

Thanks for the offer spica, but I will probably get a kit with the extras already built in.

Regarding the hum problems...

Not everyone has it, and not everyone who has it notices it.

I say 'must-have' because it basically guarantees that your build will be completely 'Humphrey'.

If you have one built, and haven't noticed any hum, just try turning it on, and listening to the output with no signal present.  -Turn it up until you hear the hiss. -If you hear hum in with the hiss, that can be eliminated.

I tried adding 100µF across both rails at about a dozen points on the board after the regulator (basically near every IC), as well as another thousand on each rail before the regulators, and I couldn't get it all that much better. -But the C/R/C didn't just reduce it... it decimated it. -I mean it's so far gone, it might even be in HYPERSPACE!  ;D

I think that builds which have more current consumption might also suffer more greatly; so if you have turbo, dual sidechains, relays, illuminated buttons, bargraph metering and lord knows what else, you might be causing more ripple on the lines, and the problem with the existing GSSL layout is that any modulation of GROUND reference tends to get picked up at the current-to-voltage converter stage immediately following the VCA.

So if you only hear 'inky-black silence' when you wind a ton of gain onto the output of a GSSL, you're in luck. -For the majority though, a C/R/C/R/C filter stage on both incoming rails will insure that current flow is smooth and gorgeous, and the only noise you should be able to detect is the gentle hiss of the semiconductors.

Keith

I built a GSSL a long time ago. Pretty much never used it. Then I added the super side chain. Now I love it. The designer of that board has my greatest respect.

Never tried the turbo tho so can't comment. I would have to build another one to even try it.

But I did add the ps filter from Expact audio? If I spelled that correctly? And was worth it's weight in gold. I can use that box on anything now. And I do.

SSLTECH is correct that filter board makes it a pro piece of equipment. And was beyond cheap. Thanks btw.

John

Expat (from ex-patriate) -- Two brits living in the USA.