Strange rangemaster problem with JTM45 hi bright channel!

[ericohman]

When I connected the rangemaster to the JTM45 there was no sound, which was strange since I have had it on breadboard for months. To varify, I checked it with two other amps and it worked on both. I tried again on the JTM45, still nothing, this was on the hi inputs (1 and 2). I then connected it to the low-gain input and it worked perfectly on both. To verify that everything was working I connected the guitar straight to the amp hi inputs 1 and 2, both worked.

I then connected the rangemaster to the hi input 1, AND, while strumming I removed the battery from the rangemaster and voilá, the sound faded up and worked for maybe 5 seconds before the caps on the rangemaster was fully drained and sound faded out (obviosly).

Here's the breadboard, btw, there's quite a POP sound when I plug in the jack in the amp.


I use pots for setting bias.
Let me know what could be the problem, I believe it's in the rangemaster since the amp works (both channels) with my Guv'Nor pedal.

[slacker]

your output cap is connected wrong. Both legs are in the same column of the breadboard, so the cap is shorted out and you will have some DC voltage on the output, this is probably what's causing the problem.

[ericohman]

Thanks! I'll try that. It worked in the normal channel of the amp though...

[ericohman]

Thanks again. Just tested and it works fine. Got a bit worried yesterday because it worked on the Lo inputs on the jtm45 clone but not on the hi. Glad it wasn't amp related

[Paul Marossy]

your output cap is connected wrong. Both legs are in the same column of the breadboard, so the cap is shorted out and you will have some DC voltage on the output, this is probably what's causing the problem.

Sharp eye!