SSL 4040G+ Issues and Questions

[Siegfried Meier]

Hey all!

We finally acquired one, after searching for nearly 25 years...it's an excellent condition SL4040G+ from August 1998 that was filled with 32 channels and the last bucket empty. There's a few gremlins to sort out, but it's all wired up with a new SMPS that our tech designed and built and running beautifully - the sound is unreal, and we couldn't be happier.

So, onto a few questions. The last bucket came empty from the factory with blank panels over it, and I've acquired a few channels to install into it. However, it won't power up as the others do - I would assume I'd see VU lights, but I don't get that or power to the channels I've purchased. Is there something I need to enable or activate somewhere to get that last bucket to work? I know the 20v rail switches and breakers are there under the patchbay, but are there fuses anywhere inside the desk to make that last bucket work?

The channels that I found for it are three 6kG with black EQ three 6kE with brown EQ and two 6kE with black EQ.

Any help much appreciated!
Thanks,
Sig

 

[Siegfried Meier]

I popped off the bottom panel after tracing what I think is the main power run to each bucket, and this little relay board of some kinda was just sorta hanging there...I don't really understand how it's supposed to attach, and it looks like the bracket was broken but nothing seemed to fall out.

I also tried adjusting that potentiometer on the bottom, but no difference. Is this little guy faulty?

 

[Siegfried Meier]

I actually just removed it and plugged in the power direct as I noticed the 4th bucket didn't have one of these...and we now have power!

What is this board?! And do I need it?!?

 

[Khron]

Might it have been some delayed power-up circuit, to lessen the power-up overall current-spike?

 

[Brian Roth]

I actually just removed it and plugged in the power direct as I noticed the 4th bucket didn't have one of these...and we now have power!

What is this board?! And do I need it?!?

I dug in my 4K files and found the schemo for the 82300 card (number seen on foil side of the pic above). @Khron called it...power supply delay unit. The SSL power supply index page says it is "mounted in console". My hunch that the trimmer is dialed so each bucket is delayed by a different time. I'll see if I can find info in the bucket section of the manual. I am not totally up to speed on the myriad details of a 4K...just worked at the module level.

Bri

 

[Siegfried Meier]

Ahhhhh excellent, this makes a lot of sense!!

So, since we got a new SMPS for the console, is this even necessary? And, the fact that it wasn't allowing power through anyway...I'd assume perhaps the relay was stuck or something? The console is 27 years old, and that bucket has never been powered on before, so that seems to make sense. It's comical how much brighter the VU meter LED's and track switching LED's are on that bucket compared to the rest.

Thanks!!
Sig

 

[Brian Roth]

Perhaps someone with more 4K experience can chime in.

I think the "staged delays" make sense to reduce inrush current as a bazillion rail bypass caps suddenly start to charge.

I am also puzzled by "It's comical how much brighter the VU meter LED's and track switching LED's are on that bucket compared to the rest." That implies a bad lack of voltage regulation....NOT a good thing.

Bri

 

[radardoug]

I think Bri is on the right track with the reduced inrush. But you should check that voltages in that bucket are correct. I dont think leds wear out like that.