Bittlehead crack hum [resolved]

Applemacman · 1236

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Offline Applemacman

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on: April 11, 2021, 05:03:50 AM
Hi after several months of non problematic use, this morning I switched on my bottlehead crack sound only came out of right channel. So took it to the bench to have a look could not see any issues and bearing in mind been working fine for several months. Switched it back on and now no sound out of either channels but a low hum that gets a bit louder if you turn the volume up. Any ideas?
« Last Edit: April 11, 2021, 07:36:47 AM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: April 11, 2021, 05:04:41 AM
I would check your voltages.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Applemacman

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Reply #2 on: April 11, 2021, 05:40:03 AM
Ok voltages
1.  71
2.  154.1
3.  0
4.  154.3
5.  74
6.  0
7.  96
8.   0
9.   97.9
10. 0

Speedball
OA.  95.2
OB.  95.4
G.    0
B+.  153.1



Offline Paul Birkeland

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Reply #3 on: April 11, 2021, 06:14:59 AM
This is most likely a loose solder joint, but the voltages don't point to anything specific.  It doesn't take more than 15-20 minutes to just reflow each joint, but generally you can skip the solder joints with the LEDs and the joints on the power switch.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Applemacman

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Reply #4 on: April 11, 2021, 07:07:12 AM
Well dont I feel the stupid one, after all this ive discovered its the rca leads from the riaa to the bothlehead crack which ate the issue.