Integration high voltage

Karl5150 · 3466

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Offline Karl5150

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on: June 02, 2019, 01:57:38 PM
   The complete rebuild of my Reduction was successful, the Integration was not. I used the boards from he original build. The SR board is fine but 2 LEDs on the C4S board installed on the B/Left channel side don't light and the voltage to OA was high.
   Thinking the board would likely need to be replaced I swapped it end for end for S&Gs. The OB then read high and that half's LEDs didn't light but the OA half's did.
   Did a visual and resistance check of the tube and RIAA wiring (trying to compare the A B sides to each other) and couldn't find anything a-miss.
   Related voltages:

      2 - 72V
      4 - 105V      OA - 68V   OB - 73V
  7/15 - 66V
____________________________________________________

18/26 - 101V
     29 - 104V      OA -101V  OB - 69V
     31 - 64V

Where should I be looking?
Thanks for any guidance,
Karl.

Karl
Downstairs: Planar3>PH-16>Stereomour II>OB Betsy+
Upstairs: RP1>Eros/CD5004>Seductor (2x Monoblocks)>FH3
Office: Modi Uber 2/Sirius>SEX2.1.1>µFonken FF85WK + DC160 subs
BR: FiiO M6>SEX3.0.1>ScanSpeak 10F + TangBand W6 (Mono)/DT770Pro
Garage: X12 streamer>Quicksand>Minimus 77


Offline Paul Birkeland

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Reply #1 on: June 02, 2019, 02:27:12 PM
I am guessing that you are also experiencing an LED on the 9 pin socket that isn't illuminating? 

My strongest suspicion is that somewhere along the path of the bare buss wire on that side of the amp that goes out from the ground lug and snakes its way around, you have a flaky solder joint.  Things were OK enough in the original build, but when installing the integration you have nudged a wire loose and you need to go over the build and figure out where this is. 

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Karl5150

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Reply #2 on: June 02, 2019, 03:44:41 PM
Thanks Paul, I'll look more closely at that.

Karl
Downstairs: Planar3>PH-16>Stereomour II>OB Betsy+
Upstairs: RP1>Eros/CD5004>Seductor (2x Monoblocks)>FH3
Office: Modi Uber 2/Sirius>SEX2.1.1>µFonken FF85WK + DC160 subs
BR: FiiO M6>SEX3.0.1>ScanSpeak 10F + TangBand W6 (Mono)/DT770Pro
Garage: X12 streamer>Quicksand>Minimus 77


Offline Karl5150

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Reply #3 on: June 04, 2019, 02:52:27 AM
Paul,
  While both LEDs on the socket were illuminated, a second (and third) look and some probing with chopstick turned up a bad joint where I had removed one of the 18K resistors for the C4S install. Thanks for keeping me on task.
  Related, I remember the terminal strips I used in the rebuild were difficult to work with, particularly the lower holes. I wiped them with denatured alcohol with some, obviously limited, success.
Thanks again,
Karl

Karl
Downstairs: Planar3>PH-16>Stereomour II>OB Betsy+
Upstairs: RP1>Eros/CD5004>Seductor (2x Monoblocks)>FH3
Office: Modi Uber 2/Sirius>SEX2.1.1>µFonken FF85WK + DC160 subs
BR: FiiO M6>SEX3.0.1>ScanSpeak 10F + TangBand W6 (Mono)/DT770Pro
Garage: X12 streamer>Quicksand>Minimus 77