Check out the new Tape Project website at tapeproject.com, now with online ordering. Inventory is updated every week, so stop by often to see what we have in stock.

Author Topic: Revox A77 Abbey Road Mod  (Read 8396 times)

Offline pederb

  • Jr. Member
  • **
  • Posts: 22
    • View Profile
    • Vinyl Pussy Cat Records
Revox A77 Abbey Road Mod
« on: February 26, 2016, 05:38:32 AM »
Hello,

Do anybody here have a schematics on how the so called EMI / Abbey Road mod is done ? It bypassed the microphone amps in the recording path

Cheers
-Peder Beckman-
Adagio Audio & Music
Vinyl Pussy Cat Records

Offline eds65gto

  • Newbie
  • *
  • Posts: 1
    • View Profile
Re: Revox A77 Abbey Road Mod
« Reply #1 on: September 21, 2016, 01:54:07 PM »
  Hi:
  To modify the A77 to bypass the input board jumper pin 1 to pin 4 , and pin 7 to pin 10 with a 5k resistor, This eliminates the input board.
  You can also replace R809 on the playback amp board with a 10 K trimpot to adjust the hi freq equalization on playback.
  These and other mods are from an article " Greening the Revox A77 " by Charles Repka from Audio Amateur magazine 4/1981 issue.
  You can also check out posts from " Audio Karma "  "Diy Audio " and " Reel to Reel Groups "
  Hope all this helps
  Ed