Traynor YCV80 problem

[bucky katt]

recently i got a used Traynor YCV80 at the Charlotte Guitar Center and i'm just in love with this amplifier, the clean sounds which i use 90% of the time are just right for me, i like it better than the silverface fender twin i used to have. i have just one problem with it and that is when i hit the standby switch the pilot lamp goes from red to yellow but i still get full sound out of it. does anyone here have a Traynor YCV series amplifier and have you had this problem? if so was it an expensive fix? the local amp repair guy wants 80 dollars before he'll look at it. i can do PCB soldering if necessary and i've built a couple of small class a tube amplifiers but diagnosis with such a complicated amplifier is way the hell out of my league. any suggestions would be greatly appreciated. i've been playing for 35 years and i try to do as many repairs as i can but if theres any doubt at all in my mind, it goes to a pro.

[dean8020]

Hi,
My thoughts for this involve the high voltage supply to the valves, I would not advise attempting this fix yourself, I would personally get the guy in the guitar shop to do it, maybe he will offer a reduced rate if you point him at a likely problem?


The standby switch in that amp is a dpdt,
The first half switches the LEDs from red to yellow, while the second half drives the input of an opto-coupler which switches off the HV supplies for the valves.

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My first thought would be that this opto-coupler is not functioning correctly, so the supply is staying on while the LED is changing.

The opto-coupler is located as follows:

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and here is the pin out



Under normal operation of standby pins 4 and 5 would become connected.

AS YOU CAN SEE THESE PINS ARE CONNECTED TO THE HIGH VOLTAGE LINES, I WOULD NOT RECCOMMEND TESTING THIS YOURSELF