(I think) blown capacitor on new crack build [resolved]

rat3hat · 4395

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Offline rat3hat

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Reply #30 on: July 11, 2020, 11:20:55 PM
There was a poor solder joint at the bottom left-most (closest to the 9-pin socket) point of the headphone jack. There are 2 black wires connected to it and a repeat of the "pencil test" with a bit more vigour revealed consistent crackling when either black wire was touched.

I have plugged in proper headphones finally.

I'll use it for a bit, then swap some tubes, then put in the Speedball in a few weeks.

Thank you again for your help. It has been humbling and rewarding.

Best,
Chris



Offline Deluk

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Reply #31 on: July 12, 2020, 01:54:02 AM
Don't forget to replace the led.



Offline rat3hat

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Reply #32 on: July 12, 2020, 04:13:27 AM
Thanks for the reminder. I absolutely would have forgotten to do that. I've just ordered a replacement pack from the Bottlehead shop.  Is it safe to use the amp normally before this is replaced? If not a safety issue, is there a quality issue?

What electrical function does the LED serve? Does it drop the voltage slightly or something along those lines?

Thanks again.




Offline Natural Sound

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Reply #33 on: July 12, 2020, 05:16:27 AM
Thanks for the reminder. I absolutely would have forgotten to do that. I've just ordered a replacement pack from the Bottlehead shop.  Is it safe to use the amp normally before this is replaced? If not a safety issue, is there a quality issue?

What electrical function does the LED serve? Does it drop the voltage slightly or something along those lines?

Thanks again.
Wait until you get your replacement LED's. Their function is to bias the cathode on the 12AU7.



Offline rat3hat

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Reply #34 on: July 12, 2020, 05:45:50 AM
Thank you.



Offline Paul Birkeland

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Reply #35 on: July 12, 2020, 09:54:06 AM
The amp is 100% safe and fine to use with one LED if you have the jumper between A3 and A8.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man