Voltage issue during Speedball install [solved]

dpat1 · 1648

« previous next »
Pages: 1   Go Down

0 Members and 1 Guest are viewing this topic.

Offline dpat1

  • Jr. Member
  • **
    • Posts: 20
on: February 06, 2014, 06:18:51 AM
All,

Searched the forum and could not find anything similar. Installed the speedball and terminals 1,5,A1,A6, B1 and B4 are all at 185V. The LED's on the big board light up fine the LED's on the small board do not light. Any clues as to where to look?

Thanks,
David
PS the Crack worked fine before the install.
« Last Edit: February 13, 2014, 04:17:03 PM by Caucasian Blackplate »


Offline Paul Birkeland

  • Global Moderator
  • Hero Member
  • *****
    • Posts: 19751
Reply #1 on: February 06, 2014, 06:27:00 AM
185V would most often indicate that the R1's on the little boards should be on the big boards, and the R1's on the big boards should be on the little boards.

Not having the LED's lit on the little boards will often mean that the center leg of each MJE-350 needs to be reheated.

As always, if you accidentally swap 2N2907's with 2N2222A's, or put something in backwards, undesirable voltages will abound.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man

Offline dpat1

  • Jr. Member
  • **
    • Posts: 20
Reply #2 on: February 06, 2014, 07:05:49 AM
You are awsome. Nailed it. Can't belive I put those resistors in the wrong place. Going to plead a senior moment. Switched them and the voltages are correct for the most part. I managed to toast one of the LED's in the process so I am going to try and find one locally. I'll post when I get it all working.

Thanks again!

David


Offline dpat1

  • Jr. Member
  • **
    • Posts: 20
Reply #3 on: February 13, 2014, 12:55:16 PM
Well I got the led in and it powered up fine and is working correctly. Sounds fantastic driving either my Beyer T1's or Sennheiser HD 700's. Thanks for the fast response and expert help.

David


Pages: 1   Go Up
« previous next »