Problem with Speedball [solved]

[Riotvan]

Hello guys, i seem to have a problem with my Speedball.

So i just built it this week, all went fine. I let it run without Speedball for a day and i had no problems and then installed it. This also worked fine for a day or so and then all of a sudden after having the crack powered on for the better part of a day i started getting a static popping hissing sound in the right channel that cuts in and out.
So first thing i did was reflow everything but that did not make any difference, then i figured maybe it's one of the small pcb boards and i swapped those around, no change.
Then i took the big pcb and turned it around because even if one side was marked "TOP" they looked identical to me, anyways that swapped the problem around to the left channel!

So i powered it up while resting it upside down in the chassis and all the red lights are glowing properly and in the same intensity. I checked all the parts and i can get them locally, should i just go ahead and get all the parts replaced and see if that helps? Since i live in Holland having you send me the parts might be expensive and i can just go to the store and get them for a couple of euro's.

Please advise 

[Paul Birkeland]

Voltages?

[Riotvan]

Sorry, here are my voltages:
1 76.4
2 168.2
3 0
4 167.9
5 79.0
6 0
7 103
8 0
9 100.9
10 0
11 0
12 0
13 167.3
14 0
15 185.7
20 0
21 204

[Paul Birkeland]

The voltages suggest that there are no issues with your PC boards.

[Riotvan]

Well then i don't know what to do next, i did try another 12au7 but that didn't change anything. Could it be the 6080? I'm pretty much at a loss here

[Paul Birkeland]

So you were able to one the popping sounds to the other channel by rotating the big PC board? I would suspect a flaky solder joint on that board that just isn't tight.

Your tubes are very likely just fine.

-PB

[Riotvan]

Yes swapping the board around also swaps the noise to the other channel. Unfortunately i reflowed the whole board but still it remains, maybe it helps if i better describe the sound?
When i power on the crack i hear the sound straight away from one of the channels and it sounds a bit like messing with the needle on a record player. Then the sound disappears for a bit, followed by a bit of a hum in the channel that works properly and a hiss in the bad channel. The hiss remains with the scratchy sound cutting in and out and it also varies in volume. Sometimes there is a bit of popping with hiss and then later it starts scratching again.

When i turn off the crack i hear the hiss becoming loud for a couple of seconds before disappearing. Also the sound is not affected by the volume pot and i have the inputs shorted and the amp is properly grounded.

Thanks for your help btw

[Riotvan]

So i reflowed the pcb again and it did not work, frustrated i gave it a rest. So after a couple of hours i did it again and made sure i got every joint as shiny as possible and it seems to be working again!

Some joints refused to get shiny until i removed all the old solder from it. I used the same temp setting as the first time, i guess i got better at it in the end

There is also just the hum in both channels now during power up and then it is silent again. I'll keep it running for the rest of the day and let it get nice and warm, see how it holds up.

Thanks again for your help Paul!

[Paul Birkeland]

Some joints refused to get shiny until i removed all the old solder from it. I used the same temp setting as the first time, i guess i got better at it in the end

That about describes the nature of soldering - only use what you need, otherwise you may not be able to adequately heat up all the solder you applied!

I'm glad you got it running; we'll always be here in case something else comes up.

-PB

[Riotvan]

Yeah this stuff is allot of fun, i'm looking forward to the next thing i can learn. I'm thinking reading a schematic and being able to translate that into a circuit. Perhaps i should follow a course