SSL 9k Balancing Boards

Hey guys,

I'm trying to use the standard issue 9k balancing boards that Gustav makes to balance the inputs and outputs of an SSL eq here.  Am I correct in assuming that they can only be used for balancing the output?  I tried using them as input, to unbalance the signal going into the circuit but can't get them to work…

Am I foolish to think that a different IC would allow this board to act as input, therefore an unbalancing driver chip would work?  Me thinks it won't work in reverse...

Any help much appreciated!
Thanks,
Sig

The THAT1646 used on this board is a balanced line driver IC. The counterpart would be THAT1246 balanced line reciever. Unfortunately those components have not the same pinout, so you can't use them both on this pcb.

What kind of SSL EQ are you refering to? I just designed a bunch of balanced line driver and reciever pcbs that will be a replacement for the balancing boards in the SSL 5K modules (Like SL502 / SL542 and so on).

You could add those modules to your EQ to balance / debalance and also get the benefit of controling the bypass directly by the frontpanel switch of the EQ.

Well, I'll use these for output, and I just bought a couple of these for input:

https://www.diyrecordingequipment.com/products/balanced-input

It's a pair of SL542 EQ's - I bought them used from someone that had racked them, but I realized they never balanced them.

It's a shame this guy has discontinued the balanced output boards though...they're a neat solution.

Siegfried Meier said:

It's a pair of SL542 EQ's - I bought them used from someone that had racked them, but I realized they never balanced them.

It's a shame this guy has discontinued the balanced output boards though...they're a neat solution.

Click to expand...

Well, my balancing boards could be the easierst solution for your EQs. Just put them in the empty sockets and add two missing Jfets and you have perfectly balanced in and outputs.

Send me a link!

Hello All,
Siegfried Meier wrote :
"  It's a shame this guy has discontinued the balanced output boards though...they're a neat solution."

I agree with you 100% !
I had bought some in the past,  and they were nice boards.
I was surprised to discover they were not made anymore, only the balanced input module is still available.

I complained about it @  DIY RE,  and the answer was : " no enough sales of this model ".....  :-[ :-[
Best,
Guy

Should just give us the layout so we can make our own boards for it...

Siegfried Meier said:

Should just give us the layout so we can make our own boards for it...

Click to expand...

The layout for the SSL9K balancing pcb's is available, it's in the SSL9K building pdf

Note that this layout was made for the old SSM2142 IC,
if you use it with the THAT1646 you don't the short circuit protection and the phantom power protection and that is already included inside the chip.  So 2x 51r, 2x 10K and 2x series capacitors are not needed.
In the end you only really need the THAT1646 and you can even use it on a verobard