Dubka

SSL 4000 EQ
« on: August 21, 2011, 03:13:14 PM »
So, we have the buss compressor, the dynamics section, the mic pre and the talkback compressor...

BUT NOT THE WORLD FAMOUS 4000 EQ?!!

What's the deal?  No schematics?  No interest?


baadc0de

Re: SSL 4000 EQ
« Reply #1 on: August 21, 2011, 03:19:37 PM »
no magic pots?

MikeClev

Re: SSL 4000 EQ
« Reply #2 on: August 21, 2011, 03:34:57 PM »
Isn't the problem with this EQ that it has odd multi gang pots with different values on each section? Easy for SSL to buy in multiples of 10s of thousands, not so good for DIY.

I wonder if multiway rotary switches could be substituted if the pots set something non critical like bandwidth...
Soldering burns: No pain, no gain.

If my opamps can't be discrete, I at least try to keep them discreet.

ruckus328

Re: SSL 4000 EQ
« Reply #3 on: August 21, 2011, 06:08:15 PM »
I was trying to think of something to work on next, this has been on my "maybe" radar for a while. 

Almost done with the talkback and after that I'm free for something else.  And honestly I'm kind of compressored out - would like to tackle an eq or pre next.  If nobody else wants to take this on I'm up for it (provided I can address the Pot issue - which I think should be feasible actually)
Serpent Audio™ - SB4000 & SA-3A Boards & Parts Kits / SB4001 Preorder / Send 'N Blend

www.serpentaudio.com

Dubka

Re: SSL 4000 EQ
« Reply #4 on: August 21, 2011, 06:54:41 PM »
Mate, please do!!

Seems crazy nobody's done it yet..

Ptownkid

Re: SSL 4000 EQ
« Reply #5 on: August 21, 2011, 07:26:27 PM »
I had been thinking about this lately as well...provided I can get a good quote on the pots...let me know if and when you decide Ruckus so we don't tackle the same thing. Especially considering you'll totally whoop my arse on the pcb design and I'd feel like less of a man. lol

Re: SSL 4000 EQ
« Reply #6 on: August 21, 2011, 09:40:32 PM »
I do believe I need 16-32 of these  ;)

Dubka

Re: SSL 4000 EQ
« Reply #7 on: August 22, 2011, 08:24:50 AM »
I do believe I need 16-32 of these  ;)

Exactly!  Everybody does..    8)


keefaz

Re: SSL 4000 EQ
« Reply #8 on: August 22, 2011, 08:30:33 AM »
Maybe some pots can be found at SSL store ?
http://store.solidstatelogic.com/catalog/46


okgb

Re: SSL 4000 EQ
« Reply #9 on: August 22, 2011, 09:02:18 AM »
Or Colin at aml can come up with something [ grp buy ? ]
GKB Audio / Greg Boboski


Re: SSL 4000 EQ
« Reply #10 on: August 22, 2011, 09:30:21 AM »
Maybe some pots can be found at SSL store ?
http://store.solidstatelogic.com/catalog/46
wow, they certainly don't give those away.

peterc

Re: SSL 4000 EQ
« Reply #11 on: August 22, 2011, 10:03:09 AM »
I had a look at the schems again, the only triple gang pot is in the filters (HPF I think)

The cut/boost pots are centre-tapped (4 terminal), so those would be the problem....
If opportunity doesn't knock, build a door.

dustbro

Re: SSL 4000 EQ
« Reply #12 on: August 22, 2011, 10:20:26 AM »
Isn't the problem with this EQ that it has odd multi gang pots with different values on each section?

Here's what the POT situation looks like for the 611 E/G EQ

47K A/LOG TRIPLE GANG - HF
47K A/LOG DUAL GANG - HMF Freq
10K LOG DUAL GANG - HMF Q
47K DUAL GANG - LF
10K LOG DUAL GANG - LMF Q
47K A/LOG DUAL GANG - LMF Freq
47K A/LOG TRIPLE GANG W/ SWITCH - HPF
10K LIN DUAL GANG W/ SWITCH - LPF

The older versions dont have a switch for the HPF/LPF, so maybe it can just be a separate toggle switch to keep costs down.

dustbro

Re: SSL 4000 EQ
« Reply #13 on: August 22, 2011, 10:25:04 AM »

The cut/boost pots are centre-tapped (4 terminal), so those would be the problem....

Isnt this just for the TR computer?

peterc

Re: SSL 4000 EQ
« Reply #14 on: August 22, 2011, 10:30:59 AM »
I looked at the schems on this page:

http://www.ka-electronics.com/images/SSL/ssl_drawings_index.htm

and the HF sections use a dual Alog 50k pot.

On the 82E02, the HPF is also a dual section pot and not a triple.

The 82E02 looks the simplest to copy as there is no electronic switching eliminating a bunch of FETs.

Peter
If opportunity doesn't knock, build a door.

signalflow

Re: SSL 4000 EQ
« Reply #15 on: August 22, 2011, 10:55:43 AM »
Alpha, has some available for special order.  I'm sure min is 1000+ but that's just my assumption.
http://www.alphapotentiometers.net/html/16mm_pot_8.html
Though they don't offer 25K on the website they might do that value for an extra charge.  Unless we can get away with 22K....

Also colin already carries the triple 47K rev for bruno's 4k-500 pre.
http://www.audiomaintenance.com/acatalog/om-01-080_extended_info.html

Seems everyone's been doing research on this one lately!

-Casey
The shortest distance between two places is a nap.

bruno2000

Re: SSL 4000 EQ
« Reply #16 on: August 22, 2011, 11:50:04 AM »
I built up 14 of these several years ago using the original 262 cards, plugged into a motherboard of my design that held the pots and a 241 mic pre, and did not use center tapped nor detented pots.  Worked OK for me. 
Best,
Bruno2000
« Last Edit: August 22, 2011, 12:24:03 PM by bruno2000 »

abechap024

Re: SSL 4000 EQ
« Reply #17 on: August 22, 2011, 12:49:03 PM »
Best Part about DIY is we aren't trying to fit the circuit into a slim channel strip. T think most people would rather use more frontpanel space with easy to find pots, then less frontpanel space with expensive hard to find pots
AC Sound - some DIY circuitboards

Dubka

Re: SSL 4000 EQ
« Reply #18 on: August 23, 2011, 05:46:14 PM »
it's great to see plenty of people have been thinking about this one..
does seem kind of crazy we don't have this eq available for diy yet...
especially when you consider the pre is subjectively the weakest part of the 4000 and the talkback compressor is perhaps the least used!

Ptownkid

Re: SSL 4000 EQ
« Reply #19 on: August 23, 2011, 08:16:34 PM »
Oddly enough... I spent the day recapping these very eqs today, along with all the other cards in the console.


 

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