| Author | Message | ||
     Robert Thomas (fobile_missile) Username: fobile_missile Registered: 10-2007 |
hi ya'll, Replaced caps. While testing and prepping to bias I arced my voltmeter probe from the standby switch terminal to the chassis. I was getting no sound until about master volumn level 8 then a loud high freq feedback squeal. Replaced 1 meg master volumn pot. now getting immediate high freq squeal from low and high power settings as soon as I turn on standby switch. I flicked standby switch off instantly. All electrolytics were dropping correct voltages yesterday before I changed out the volumn pot. There was no feedback at that time because I beleive the master vol was inoperative? Anyone ever get immediate high freq feedback from turning on the standby switch? Is it possible the standby switch is no good? It registered good voltages on the low and high settings yesterday before changing the master vol pot. Thanks to all answers. | ||
| Robert Thomas (fobile_missile) Username: fobile_missile Registered: 10-2007 |
ok, phase circuitry panel has 2 exit wires going to the #6 pin for the tube sockets, blue and brown wires. I disconnected these 2 wires and lifted the panel board to install the new electrolytic 150 cap. After connecting the cap I connected the wires opposite and the circuit was oscillating!!! hahaha!!!. Clean signal has returned. Now, back to the op amp experiment.+++ |