DBX Gold Can VCA "Sound"?

Hey guys!

I routinely notice people chasing DBX gold can VCA's, presumably for their SSL clones.
Do they actually sound any decent compared to modern replacements like the THAT 218# series?

Perhaps this sounds like a stupid question, but in my MCI 600 I have loads of gold can VCA's in the automation system.
As soon as you flick every channel of a mix from the VCA equipped large faders to the small old fashioned potentiometer small faders, its like a revelation!
Everything becomes brighter, wider, clearer!

I admit that this might not be directly caused by just the VCAs. Perhaps the fet switching, etc in the faders adds to the subtle but rather noticeable change in sound.

So my current conundrum is:

Do I pinch a pair of gold can's from my MCI for my Mixbuzz 500...
...or do I just go with modern replacement parts?


thoughts? anyone done a direct comparison?

I would say,

Swap them and see for yourself, you might (or not) like it.

Depends on how good you null out distortion on the 202.

I can't myself hear the difference between a 2181LA and a first-grade, well-adjusted 202C "Goldcan" - but i bet that there are someone out there that can (or at least will claim to).

In any case, the difference is small, and not necessarily in favor of the 202 - unless you like it trimmed a bit off. Many do.

Jakob E.

My tuppence…

In a perfectly scaled situation, the differences will appear very small. However, when driven the DBX 202c has a certain charm.

Hi,

i never heard a DBX 202, but what I can put in the ring is a A/B test of my GSSL with THAT-Cips against a SSL 4000 desk
at the studio of a friend of mine (www.heyday-studio.de) some time ago.

The shoot out result....
well the desk wins... but the GSSL with some EQ treatment* is soooo close...
Turbo-Mode is the man of the day!! It's so much closer to the desk...

ROCK-ON!


* (7kHz@0,6bd, 1,75kHz@2db, 200Hz@1db, 100Hz@0,5db)

There is a certain charm to the Gold cans.
It's always difficult to define what's happening to an audio signal under dynamic conditions, as opposed to steady state signals like tones. But I can say that my original SSL clone - built in the 80's with 202c's still sounds the best to me.

There is a certain charm to the Gold cans.

Click to expand...

yes, I just made the switch over from 2181LA to 202c and the gold cans are more gooey sounding and more laid back. The 2181 is punchier and more open, which is also cool for some stuff. I wish I could make the VCA's switchable, but my board is already such a mess from all the modifications  ;D

Very interesting, was that just removing all the components in the 202 emulation circuit and dropping in the 202c that the compression amount stayed exactly the same the only difference was a 0.5dB increment in makeup gain. I verified this with a signal generator and level meter on my fully switched unit (yes, also threshold and makeup gain).

It seems I will build another unit with the black can 202 that I also have here, will be interesting to see how they perform.

FWIW, I remember comparing a black can turbo'd GSSL to the rack mount SSL comps (IIRC they had paralleled DBX or THAT IC VCAs), and there was not that much (audible) difference once levels were all equalled.  They both sounded good, and the GSSL wasn't mine, so I only really listened for a few minutes and called it a day.  I still haven't tried the gold cans I have, sometime....

Wouldn't more changes be had by fiddling with the sidechain than the VCA?

Also, does anyone know the difference between the 202C and the gold cans used in the DBX 903's? Are they the same thing?

There's a db/mv difference between the black can and gold can VCA's.  This "Design note" from THAT Corp gives up the goods:

http://www.thatcorp.com/datashts/dn127.pdf

I know, the GSSL was set up taking all that into consideration, and had been calibrated properly. But the sound was not very different between that and the SSL rackmount comp. 

I still wonder if the 202C gold is the same as the 903 gold can? 

I'm certain they are, you can also find them in MCI consoles.

mitsos said:

I still wonder if the 202C gold is the same as the 903 gold can?

Click to expand...

Mark

Biasrocks said:

I'm certain they are, you can also find them in MCI consoles.

mitsos said:

I still wonder if the 202C gold is the same as the 903 gold can?

Click to expand...

Mark

Click to expand...

Good to know! thanks!

Has anyone ever unpotted/traced a gold can VCA? 

Yes. I've un-potted one.
It full of 'selected' components - especially the transistors.
There's lots of thermal coupling i.e. metal clips bringing 2 transistors into close proximity.
It looks quite labour intensive!

Any chance you may have traced it?  With todays "matched" transistors, maybe we could make it a bit less labor intensive?

I actually think it would be less expensive and time consuming to track down a Gold Can than attempt to build one yourself.
The schematic is floating around here somewhere.
If you really want to see a picture of an un-potted module I could send you one.

Attached DBX202 schematic - 1975 version...

Jakob E.

dbx202_pic1.JPG

dbx202_pic2.JPG

Good stuff Jakob.
My DBX202C gold can (which came from an MCI console), has a completely different layout.