Help: Troubleshoot Speedball

Noskipallwd · 3257

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Offline Noskipallwd

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on: August 28, 2011, 12:45:45 AM
Hello,
I would appreciate some help troubleshooting my Speedball install. The stock crack build was fine and sounded great. After the Speedball install I have some LED and voltage problems. I performed all the troubleshooting  I could, reflowing solder joints, verified all connections were proper, but to no avail. The second LED from left on the left hand small board is dead, on the left side of the speedball board the LED second from left is dead (no light). The rest of the LED all light but most are very faint. The A3 light is faint where it was strong before, the lights on the right hand of the Speedball board are faint as well as both on the right hand small board. The tubes light up fine, I did switch out both tubes to eliminate them as problems. So here are some voltage readings, I'll just list the erroneous readings.
Terminal.          Expected.        Actual
2.                      170.              77.6
4.                      170.              77
5.                      75.               48
7.                      100.              72
9.                      100.              45
13.                    170.              75
15.                    185.              122
21.                    206.              170
A1.                    75.                46
B2.                    170.              75
B3.                    100.              70
B4.                    75.                46
B5.                    170.              75
B6.                    100.              44

Well that's all the bad ones, thanks in advance to anyone willing to help.

Shawn Prigmore


Shawn Prigmore


Offline Noskipallwd

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Reply #1 on: August 28, 2011, 09:24:15 AM
Well I found the problem, switched transistors on the left small board and left side of the speedball board, desoldered them and installed correctly. All the voltage readings are within specs. Sounds fantastic!

Shawn Prigmore

Shawn Prigmore


Offline Doc B.

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Reply #2 on: August 28, 2011, 05:13:11 PM
Good job of sleuthing, Shawn! Glad you got it running.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline Noskipallwd

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Reply #3 on: August 28, 2011, 11:05:26 PM
Thanks Doc, I was lucky enough to find a previous post from someone who did the same thing! I am really pleased with the Crack, my first foray into tube based headphone amps was a Scihiit Audio Valhalla. The Crack is head and shoulders above the Valhalla, even in stock form. There was one interesting thing I encountered while troubleshooting, the only other compatible tube I had on hand was a TS 5998. i rolled it in to eliminate tube problems, I also checked voltages with it in and noticed an increase in voltages of between 6-10 at most terminals. I was surprised at the amount of increase. I am running the 5998 and a Mullard CV 4003 in the amp and I really like this combo. Now I have to troubleshoot my Saeco espresso machine, starting to have withdrawls.

Cheers,
Shawn Prigmore

Shawn Prigmore