ReHousing SSL 4000 EQ and Dynamics Modules

[DigitalMetal]

Hi All !


I (perhaps rather foolishly) have purchased a 2x pairs of SSL 4000 EQ and Dynamics modules.


What i have is just the boards circled in red in this picture here,

I have the drawings for the modules, Available here:

http://www.ka-electronics.com/images/SSL/ssl_82E10.pdf

http://www.ka-electronics.com/images/SSL/ssl_82E02.pdf

And they look fairly simple to hook up to some Pots, switches and LED's & I have a power supply soloution already

I said, perhaps foolishly as it seems i might have a hard time finding some suitable pots for the EQ's

For the:

Frequency pots i need: 50K Dual Gang Reverse LOG

Gain pots i need: 25K LIN Centre Tapped, Centre Detented

Q bandwidth on the H/L Mid i need: 10K LOG

Low Filters: 50K LOG Dual Gang

Hi Filters: 10K LIN Dual Gang

Can anyone help suggest somewhere i can get hold of these pots ?

Id really like to get all the same brand so the EQ's feel the same to use on each knob bit i cant find the Gain pots anywhere.

Any helpful suggestions?

The Dynamics pots seem to be a little more straight forward,

I need:

Compress
Ratio: 10K LIN Dual Gang
Threshold: 10K LIN Dual Gang
Release 250K LOG

Expand:
Threshold 25K LIN
Release 250K LOG
Range 25K LIN

Does anybody perhaps know a supplier of spares for SSL 4000/6000's that might be worth approaching?

Im going to email Recycled Audio here in the UK to see if they have any but if theres anywhere else i should be trying for new of used, or if you yourself have some you will sell me please do chime in.

Thanks !

Neil

 

[jensenmann]

Now you know the reason why not so many of these modules get racked.
Omeg sell pots in low quantities (from 25+). They are helpful and open for custom jobbies, don´t know if they do center tapped pots, though.

Good luck und keep us informed how it worked out  ;D

 

[nielsk]

Get some of the proper ones from the various guys parting out old SSLs...

 

[mata_haze]

Recycle..your only chance in UK.

Good Luck!

Mattia.

 

[DigitalMetal]

Thanks for the input so far ,
ive emailed Recycled Audio hopefully they will have some,
maybe with a bit of luck somebody will see this thread that is breaking down a desk or has some spares.

 

[bezen4uk]

Hi,
You can try Vishay(Sfernice) conductive plastic pots.
http://www.audiomaintenance.com/acatalog/potentiometers_conductive_plastic.html

 

[abechap024]

Probably not the easiest...but you could always just make stepped attenuators at any values you want...if you can't find any pots.

 

[DigitalMetal]

Thanks everyone,

Can somebody shed a little light on what a "Centre Tapped" pot is and why it might be important in this case on the gain pots?

I got this info from Keith "SSL Tech" posting in a previous enquiry thread by someone else here:

http://www.groupdiy.com/index.php?topic=2618.0

 

[Sammas]

A single ganged pot usually has three connections,

One at each end of the resistive track (the two outside lugs/pins on the pot), these are static and never change.

and the wiper which moves against the resistive track to create the variable resistance/voltage division.


A center tap is a third static connection to the resistive track at a chosen resistance value. It doesn't change with the wiper. It is common in gain pots as it aids in better aligning the "0dB" mark, I believe.

 

[ruairioflaherty]

A center tap is a third static connection to the resistive track at a chosen resistance value. It doesn't change with the wiper. It is common in gain pots as it aids in better aligning the "0dB" mark, I believe.

Depending on the design in question it can also help minimise interactions between bands.  There has been discussion of these centre tap pots here before.  I remember a post by a one time SSL designer where he felt you could try it without. If you can find the right combo of keywords there is more info to be had on this.

Finding these pots will not be cheap.  They are out there but as a dwindling SSL spares resource they are commanding a price.  That said you may get lucky, I gave away an almost complete stereo set of eq pots to a fellow member a few months back.

Good luck.

 

[DigitalMetal]

Ah that would make sense as to why there are 4 points on the pots on the circuit diagram
See Here:

Out of interest how do i know which terminal is the centre tap and which is the normal common centre?

Thanks everyone so far i really appreciate the help!

Finding these pots will not be cheap.  They are out there but as a dwindling SSL spares resource they are commanding a price.  That said you may get lucky, I gave away an almost complete stereo set of eq pots to a fellow member a few months back.

Ouch im praying someone has some kicking around that they will be willing to sell me  :'(

 

[Sammas]

What about the rotary switch suggestion. It will be more time consuming, but it means you can create any pot value you like, including a center tap.

You will also have an awesome recall ability.

I am in the process of finalizing a 2deck 23 position switch group buy (mostly for local DIY'ers), but the 23 positions gives you a "0" and 11 steps to each side.

 

[Michael Tibes]

I found this on ebay: http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=260636624590&ssPageName=STRK:MESINDXX:IT, this guy also offfers the switches amazingly cheap. Maybe we could ask whether he wants to offer neg log ones, the 50k ones would fit the sontecs as well, don't they? Should be a market.

It would also be amazing to have 4 decks for stereo eqs...

Michael

 

[DigitalMetal]

That certainly sounds like a do-able soloution for the Centre tapped one,

Could i use 47K instead of 50K and not have too much difference?

Like this one for the 50k dual rev log:
http://www.audiomaintenance.com/acatalog/SF-01-046_extended_info.html

 

[sintech]

Hey, I took my racked 2 x SSL 4000 E Series dynamics out of the rack today, as one gate had been functioning incorrectly for the last three weeks. +5v bad trace corrected, and one quad op-amp replaced, and it's all good.

The whole thing is racked with the correct SSL pots/with pull switches where needed.

I personally didn't do this conversion, but I think you can see the complexity in space.. doing the whole interconnections point to point, especially if you have the eq also.

 

[DigitalMetal]

Cool !
Thanks very much for the pictures its really useful to see how other have done it before,

I will be making exactly the same setup you have 2x EQ and 2x Compressor/Gates

Im not at all daunted by the amount of wiring involved, ive done more complex stuff, its more the electronics that i struggle slightly with slightly but i think il be ok.

Ive been talking to somebody else about the difficulty in the obtaining the pots and ive very kindly been donated some by a fellow Prodigy forum member,  Thanks Zeke !

Another person i have been talking to has made some clever suggestions on how to mod some of the cap and resistor values of the EQ card to allow me to use some more common value pots which i will try once ive used the pots ive been donated (as there are not enough to cover the whole project.

Il keep you updated on how things go. thanks everyone, this thread should serve as a quite useful resource for anyone else attempting the same project in the future.

 

[SIXTYNINER]

hi sintech
So Fucking Porn Project !

6T9R

Hey, I took my racked 2 x SSL 4000 E Series dynamics out of the rack today, as one gate had been functioning incorrectly for the last three weeks. +5v bad trace corrected, and one quad op-amp replaced, and it's all good.

The whole thing is racked with the correct SSL pots/with pull switches where needed.

I personally didn't do this conversion, but I think you can see the complexity in space.. doing the whole interconnections point to point, especially if you have the eq also.

 

[njm]

Bottom of this page has a rack job too, but using the chopped up motherboard
http://www.proharmonic.com/archive2.htm

Racked up 9000J strip on here too
http://www.proharmonic.com/archive3.htm

 

[DigitalMetal]

cool thanks njm 

Guys i also found this place that seems to offer custom builds they may only do large quantities but il ask for a quote anyway.

http://www.potentiometer.com

 

[DigitalMetal]

Started the EQ wiring today