Crack w Speedball, Final Voltage issues [resolved]

jonathan.lesser · 1493

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Offline jonathan.lesser

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on: March 05, 2023, 06:44:14 AM
Prior to Speedball, all voltages good, sound good.

After Speedball, Noise and no music left, right great

Following voltages:
OA: 62V
OB: 99V
G: 0V
B+: 176

All LEDs on

Thank you
« Last Edit: March 06, 2023, 05:12:07 AM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: March 05, 2023, 07:00:35 AM
What are the voltages on the front C4S board?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline jonathan.lesser

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Reply #2 on: March 05, 2023, 08:19:43 AM
Thanks so much Paul!


Terminal one: 64 V

Terminal 2: 185 V

Terminal 3: 0 V

Terminal 4: 185 V

Terminal 5: 0 V

Terminal 6: 0 V

Terminal 7: 102 V

Terminal 8: 0 V

Terminal 9: 66 V

Terminal 10: 0 V

Jon Lesser

« Last Edit: March 05, 2023, 08:22:55 AM by jonathan.lesser »



Offline Paul Birkeland

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Reply #3 on: March 05, 2023, 10:47:54 AM
Was terminal 5 0V when you first installed the front C4S board?  When you resolve why terminal 5 is 0V, terminal 9 will move to what it's supposed to be.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline jonathan.lesser

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Reply #4 on: March 05, 2023, 11:06:18 AM
Yes Paul, all voltages were spot on for the initial crack build



Offline Paul Birkeland

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Reply #5 on: March 05, 2023, 11:27:52 AM
If you remove the 6080 and just run the amp with the 12AU7, does that voltage at terminal 5 increase?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline jonathan.lesser

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Reply #6 on: March 05, 2023, 12:18:38 PM
Thank you, Paul, I will try to do a deep dive over the next couple of days to answer your question regarding the tubes and to focus on problems I may have caused during the upgrade. Thank you so much once again for your enormous expertise.



Offline jonathan.lesser

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Reply #7 on: March 06, 2023, 04:30:37 AM
All fixed! Found something dumb and addressed it. It sounds glorious and I appreciate your expertise, Paul, plus your endless patience.

Jonathan Lesser.



Offline Deluk

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Reply #8 on: March 07, 2023, 02:35:53 AM
Dumb or dumber, please let us know what you found. We all make mistakes or do something silly now and then.