No sound in either channel (resolved)

[Jimb0]

Just finished building a Crack with Speedball. Voltages checked out okay but I am not getting any sound. I tried using both my laptop and desktop.

 

[Jimb0]

N/m it's my Modi Multibit that stopped working.

 

[Jimb0]

Actually yes there is something wrong with the sound. It's very low and I can't get the volume to go up.

 

[Jimb0]

ok so i'm getting 1.7v at OB and OA

 

[Paul Birkeland]

At which OA/OB, the big board or the small board?  Are both tubes glowing?

 

[Jimb0]

Yes both tubes are glowing and OA and OB on the big board

LED's light up on the small board and the two at the bottom but not on the big board

 

[Paul Birkeland]

What DC resistance do you get between OA and OB and ground on the big board?  As always build photos can help too.

 

[Jimb0]

OB and OA reading infinity. Ground is reading 40 ohms.

Pics
https://imgur.com/a/eYBPLEj

 

[Paul Birkeland]

If you pop each wire out of the big board, you can take it all the way out of the amp, then just temporarily solder the 3K resistors onto the end of those wires.  It would be helpful to know if the amp works under those conditions.  Also, are the voltages on the small boards OK?

 

[Jimb0]

I no longer have any 3K resistors to test it, is there another way? I'll recheck the voltages soon

 

[Paul Birkeland]

I would obtain a pair of 3K resistors so that you know if the amp is otherwise working without the big Speedball board.  This is what I would do if I had your amp on the bench for repair.

 

[Jimb0]

Will do PB

 

[Jimb0]

Do I need the 22.1 KR ½W resistors as well?

 

[Jimb0]

OA and OB on the small board is 72v

OA and OB on the big board is 2v

B+ is at 217 on the big board

 

[Paul Birkeland]

You can leave the small board in and just tack the 3K resistors onto the wires poking up that would hold the big board.

 

[Jimb0]

just to be sure the 3K resistors are the ones that came with the non-speedball kit?

 

[Paul Birkeland]

Yes.

 

[Jimb0]

Just wanted to make sure I did this right

https://imgur.com/a/Kb6eKIB

also what voltages should I be checking here?

 

[Paul Birkeland]

7 and 9.

-PB

 

[Jimb0]

219v at 9
6v at 7