No Left channel with Speedball upgrade

Jaw22 · 3582

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Offline Paul Birkeland

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Reply #15 on: June 05, 2016, 07:12:48 AM
Just to be thorough, can you remove the 6080, then test the amp with just the 12AU7 installed.  You'll only be interested in the OA/OB voltages.  (IA/IB will be higher than expected)

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Jaw22

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Reply #16 on: June 05, 2016, 07:57:30 AM
Okay, with the 6080 removed, OA is 200V, OB is 85V, IA is 205V, IB is 205V.



Offline Paul Birkeland

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Reply #17 on: June 05, 2016, 08:01:38 AM
Can you flip the board up and post a photo of the bottom?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Jaw22

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Reply #18 on: June 05, 2016, 08:29:45 AM
Here's a photo of the small board.



Offline Paul Birkeland

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Reply #19 on: June 05, 2016, 12:06:36 PM
I would replace the white wire from OA to terminal 1.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Jaw22

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Reply #20 on: June 05, 2016, 12:26:00 PM
Replaced and still have 160V to OA.



Offline Paul Birkeland

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Reply #21 on: June 05, 2016, 03:30:46 PM
For clarification, do you have both LED's on the 9 pin socket glowing? Do they both glow with roughly the same intensity? 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Jaw22

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Reply #22 on: June 05, 2016, 03:32:11 PM
Ya, they both glow and are the same intensity.



Offline Paul Birkeland

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Reply #23 on: June 06, 2016, 07:42:01 AM
I'm still quite confident that you have a soldering issue, as the first voltages that you posted showed a working PC board, and the high voltage followed that side of the PC board when you swapped it around.   You might consider getting a hold of replacement parts to obtain a new small board for the front to give it another shot, but before you do, try reheating the board joints one more time.

When you reheat a transistor joint, wait till the entire solder pad melts, then count to 3 to let it flow well. 


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Jaw22

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Reply #24 on: June 06, 2016, 12:50:52 PM
I gave it one more try and gave the transistors a good heating the way you said to do, but still have the same issue. I think i'll just order a new small board kit and start over.



Offline Jaw22

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Reply #25 on: June 21, 2016, 02:39:35 PM
Okay, so after getting my new small board with all new parts, everything is working great now. I'm not sure what happened with the first one, maybe I somehow melted the inside of the board, but at least that was what the problem was.

The only thing I have that's annoying right now is the noise i'm getting from my computer when I go past 1/3 of the volume on the crack.



Offline Paul Birkeland

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Reply #26 on: June 27, 2016, 05:47:51 PM
Yeah, computers are notoriously noisy.  If you have a toslink output on your computer, using that to connect to an inexpensive DAC will wipe the noise out.  Also, a USB DAC with its own power brick will generally also work. 


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man