Smash Voltage Check [resolved]

wdavis009 · 22337

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Offline wdavis009

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on: January 27, 2019, 10:49:28 AM
Currently doing resistance and voltage checks on recent build. Most readings are spot on except where the manual states 45-55VDC (U15, U16, U21, U22, A2/C2 and A3/C3). I am reading 150VDC at each location. I am also not getting proper reading for A4/C4 and A8/C8. Manual states 1.57VDC but I am getting unstable readings in the mV range.
« Last Edit: January 27, 2019, 11:30:50 AM by Paul Birkeland »



Offline Paul Birkeland

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Reply #1 on: January 27, 2019, 11:07:02 AM
Can you post some photos of your build?  It sounds like your 4P1L tubes aren't conducting.  Check the wiring at the small filament board to be sure that all the wires from the STP cabling are going to the correct places!

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline wdavis009

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Reply #2 on: January 27, 2019, 11:21:48 AM
Resolved.  :)



Offline wdavis009

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Reply #3 on: January 31, 2019, 12:40:21 PM
Another question: how much static noise is normal? I expected the microphics (though its worse than I was hoping) but the static is constant out of both speakers. 



Offline Paul Birkeland

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Reply #4 on: January 31, 2019, 12:41:05 PM
This is extremely dependent on the gain of your amplifier and the sensitivity of your speakers.  If you told me that you had a 500WPC McIntosh amplifier and Klipsch speakers, this wouldn't be surprising at all. 

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline wdavis009

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Reply #5 on: January 31, 2019, 01:41:21 PM
Harbeth 7ES-3 speakers. Amps are either Audio Research, Conrad Johnson or Pass Labs (all 60wpc or less).



Offline Doc B.

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Reply #6 on: January 31, 2019, 01:52:45 PM
Do any of those amps have an input level trim?

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


Offline wdavis009

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Reply #7 on: January 31, 2019, 02:07:09 PM
No, they do not.



Offline Paul Birkeland

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Reply #8 on: January 31, 2019, 02:28:43 PM
Plug a pair of these into the inputs of your amplifier.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man