quick LED question

moviedave · 3846

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Offline Paul Birkeland

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Reply #15 on: April 22, 2013, 05:11:18 AM
Was the amplifier operating properly before the installation of the Speedball?

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline moviedave

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Reply #16 on: April 22, 2013, 05:59:09 AM
yes it was



Offline Paul Birkeland

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Reply #17 on: April 22, 2013, 06:06:02 AM
Well, the good news is that the 12AU7 is operating properly, and the two small green PC boards are A-OK.

Moving on to the large green PC board, I'd give it a solid once over again to be sure you didn't miss any joints.  Do all 4 LED's light up equally brightly? 

It's a little strange, because your 6080 is drawing some current, but not quite enough.  It's also odd that it is the same for both channels.  This makes me suspect the red wire from 2U going to the larger green PC board is not making sufficient contact, or the red jumper from B+ to B+.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline moviedave

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Reply #18 on: April 22, 2013, 06:25:03 AM
Actually, the hum is coming from the right channel along with the music.  The left is silent.  The LEDs are all bright and the 2U and B+ to B+ jumper are soldered well.



Offline moviedave

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Reply #19 on: April 22, 2013, 06:51:38 AM
The 2N2222A nearest the small PCB boards feels loose all of a sudden.  Could that be the culprit?



Offline Paul Birkeland

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Reply #20 on: April 22, 2013, 07:20:19 AM
It would seem unlikely to influence both channels, but it's worth a shot!

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline moviedave

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Reply #21 on: April 22, 2013, 07:56:08 AM
Well, now I have both channels working!  But there is still a loud hum (now on both sides, of course).  The hum is the same volume no matter what the volume pot is at.  The sad thing is, I am really starting to enjoy soldering.  I just wish it wasn't was on something else at this point.
« Last Edit: April 22, 2013, 07:59:31 AM by moviedave »