Fender 112 se

[robgrif]

fender se 112

thanks for that will try that route .i feel the solution getting closer . all this vastness from a couple of bits of silicon wafers etc. the amount of knowledge in the electronic field is amazing. i appreciate the time you all take to share it with those of us just getting their feet wet repairing an amp here and there . thanks again will try to put all hints and help to full use and keep ypu posted

[gui_tarzan]

Just a comment... I have this same amp and it's dead-quiet on the clean channel at all but the higher volumes (with nothing plugged in). I can hear a very light hiss at 4-5 and above but no hum or other noise. The dirty channel is a whole 'nother thing though which I expect. I don't change the levels when I switch channels so I'm not sure why Rob would be hearing bleed-over unless something's wrong. Maybe a bad cap?

I use a compressor/limiter to turn off my guitar signal when I'm not playing and that cuts out most of the parasitic noise from my guitar and effects pedals on the dirty channel because they mic it when I play at it at our church and it really shows up in the PA if I don't.

[robgrif]

hi all. ok amp acting strangely. i may have missed this attribute originally .the clean channel only works when the treble control is advanced passed 0 .missed this originally seeing no output from clean channel was apparent at 0 treble setting.switched out u1 thinking it was faulty but nothing changed in behaviour of amp . the volume of clean channel seems diminished compared to drive channel and only works when treble is advanced seems treble control functioning as volume on clean channel .not sure of fault now . any suggestions would be appreciated. thanks in advance .

[52 Bill]

hi all. ok amp acting strangely. i may have missed this attribute originally .the clean channel only works when the treble control is advanced passed 0 .

What are the settings of the Bass and Mid controls when you test this?

[The Dude]

If all of your tone controls are completely cut, you're not gonna get much. Remember, in effect, the tone controls ARE volume contols- just operating at certain frequencies.

[robgrif]

fender se 112

What are the settings of the Bass and Mid controls when you test this?

thanks for reply
ok other settings were at zero when they are all advanced amp seems ok
i have another amp a peavey and it does not behave this way guess it is in the design of the fender amp circuitry for this amp
so to sum up bleed through is gone .maybe was the slight solder bridge on q12.amp seems to be working now so i will keep my fingers crossed
and keep on jammin. thanks all for lessons in electronics.the thing that puzzles me most is trying to understand the signal path as it goes through different stages af the amp.i will keep on reading posts and solutions etc.to gain more understanding . thanks to all who responded.
great forum here
cheers

[52 Bill]

If all of your tone controls are completely cut, you're not gonna get much. Remember, in effect, the tone controls ARE volume contols- just operating at certain frequencies.

These controls are just like the tone stack of a 3 control Fender tube amp, when all controls are set to zero all of the signal is sent to ground.

Different amps, Fender included can have different circuits that avoid the complete grounding of the signal at the tone stack.

I find that following the signal path through a schematic is easiest if you take a printed version and a highlighter or maybe two colors of highlighter for clean and distortion paths. But it's also important to understand what each component does and what the schematic symbol for it is.

[The Dude]

Yep. Agreed. That post was directed at the OP. I saw where you were headed.