Tube Amp Archive

I temporarily clipped on a 100K in parallel with the 100K FB resistor connected to the 8 ohm tap (now 50k /47k feedback R) and it made a huge difference. 1st, it dropped the amps volume significantly & 2nd, it made the amp sound more smooth sounding like a PLEXI. I kept the 100k because I want to ke...

I put a 220k resistor on the volume control's wiper to treble control and it made huge difference. It really smooths out the taper helping to dial in the volume. I highly recommend it! Probably my favorite of all of the mods I tried. Don’t you mean from the treble controls wiped to the top of the m...

Adding a cap to the changed "cold clipper" resistor that gets changed to a 3.3k or 2.7K will add noise. try removing it and see what happens. I had the same problem when I did the JEL mod. Once I disconnected that bypass cap, the noise went back to normal (stock level). To me, the cap made such a sm...

I put a 220k resistor on the volume control's wiper to treble control and it made huge difference. It really smooths out the taper helping to dial in the volume. I highly recommend it! Probably my favorite of all of the mods I tried.

Turned out to be a faulty solder joint under the PCB! Thanks for all of the replies!

So I lifted my amp's PCB and re-flowed every solder joint and now my amp sounds normal again!!! What a nightamre
Thanks for all of the input as it helped me troubleshoot.

Yep! it was a loose or bad solder joint on my amp's PCB.

cool thanks. i'm connected to the speaker jack & I use the 8 ohm setting with my cab.

What kind of a change in sound would I expect if I change my neg. feedback from 47K / speaker jack to 100K / 4ohm tap?

I found the problem. So I think. There was a loose solder joint under the board. I finally pin pointed it after chop sticking for the third time. I have the board lifted up so I fixed that. The solder pad had lifted off of the PCB. While I'm at it, I'm going re-flow all of the solder joints. Keeping...

Thank you!

Hello. I been trying for a while now, off and on, to fix the issue I have with my Marshall Superlead. The issue I'm having is when i first turn my amp on, It makes a static sound for a about 30 seconds or so and then goes away and stays away once it is warmed up. It does this with no guitar or cord ...

Is this a clone or an original? Check things that age…my first guess is always tubes …power tubes are the usual suspects… Check bias Check amp voltages Check wall voltages unless there is some intermittent connection somewhere down the line like you theorize , it’s probably simply aging parts somew...

All of my tone controls are working normally.

pdf64 wrote: ↑Thu Apr 20, 2023 6:30 pm Is the range of control of all the tone controls normal, eg does the bass control go from too bassy at CCW to even more bassy at CW?

Yes. with the bass all the way off, it sounds real bassy then whe I turn the bass up, It gets more bassy.