Sunn Concert Controller 1 Schematic/Info?

[NsubUlysses]

Hey guys and girls I have a Sunn Concert Controller 1 that is kinda nice but does have a hum and some extraneous noise. I'm trying to figure out what's up with the caps in the power section. On the PCB it has 3 big 50v 1000uf caps that are so big they don't even fit. Whoever recapped it in the past left the stems from the previous caps in the PCB and solder the leads of these huge caps to them. They have to be like 3 inches long each.

Are these the right caps?? I can't find a schematic and I thought the Concert Series was all supposed to have the same poweramp section (I think I recall Isaac saying that somewhere??). This Concert Controller is not the same as my Concert Lead and my Concert Slave.

Any info would be much appreciated.

[loudthud]

It looks like those are the right caps, 1000uF 50V. There is a 1000uF 75V cap that does most of the filtering for almost everything except the output section of the power amp. It should be mounted on the chassis.

First you should determine if the hum is coming from the preamp or the power amp. Insert a cable into the Slave Input Jack. Short the tip to the shell. Does that kill the hum? If it does, the hum is coming from the preamp.

[NsubUlysses]

Hey thanks I will try this when I get home.

If this cap is weak/bad would it mean power loss too?? Seems like my Concert Lead is louder than the Controller, but I don't really know if that's  because the Concert Lead breaks up more at high volumes, and also has a distortion knob for more volume/gain.

But yeah I'll try this and get back with results. Thanks so much loudthud.

[loudthud]

Plug a guitar cord from the Preamp Out jack on the back of your Concert Lead into the Slave Input on the Concert Controller and connect speakers to the Concert Controller. It should sound the same as if you plugged the speakers into the Concert Lead. If not, there is a problem with the power amp in the Concert Controller.

[NsubUlysses]

Ah yes, great idea again.

So I did as you said and plugged into the slave input, and used a paperclip to connect the sleeve to the tip. The ground noise was reduced by probably 80% but was still slightly present. Guess it's time to check the caps and for loose connections in the pre section.

The pre section has 8 blue 2.5uf 64v caps, and also some black caps that are 2.2uf 25v (22 of these), and 2.2uf 50v caps (only 2 of these).

I did the chop stick thing and tapped the components on the board while the amp was on and I didn't hear any extraneous noise through the amp. I don't think it's a loose connection but I'll keep looking. If you have any more advice other than to check the caps in the pre section and possibly replace them please let me know. You've been well helpful so far so thank you.

Can't wait to get this thing running strong.