Tube Amp Archive

Make sure every single wire run that requires a shieled cable has one. Try using a chop stick to move the signal wires in the preamp section and see if the noise goes away. Be very careful doing this since the voltages here are dangerous. Cheers G I'll give this a try over the weekend, Thanks for t...

Does it still do it if you pull the chassis out of the cabinet? It sounds mechanical in the clip, but without being in the room I can't really say. I just last week fixed one of my amps that had an annoying crackle on low F. Pull the chassis out of the cab so you can see everything and poke it with...

could it be magnetostriction with the OT? also perhaps a window is rattling or even drywall panels if you're really cranked up and the amp is backed against a wall actually it may not even have to be very loud if the panel resonance is being matched perfectly by the note, it would vibrate pretty st...

could it be magnetostriction with the OT? also perhaps a window is rattling or even drywall panels if you're really cranked up and the amp is backed against a wall actually it may not even have to be very loud if the panel resonance is being matched perfectly by the note, it would vibrate pretty st...

solderhead wrote: ↑Mon Mar 10, 2025 8:48 am have you checked to be sure that you don't have any AC riding on your DC voltage supply?

Yes I have. The power supply is really clean and the amp is very quiet in all other aspects. Thanks

Have you tried a different speaker or speaker cab. Have you also tried playing in a different room. If none of the above I would bet it's a cold solder, most likely in the LNFB of the tonestack I have tried different speakers but didn't try a different room. I reflowed all the solder joints on the ...

Thanks for the suggestion Ian. Gave that a try but alas no joy.

On my VHT D50 I have noticed these artifacts when playing an F# and a bit less on a G note. I always wrote it off to my phone being in my pocket while playing but after moving my phone away it was still there. I have tried different speakers, cables, and guitars. The noise is less noticeable with OD...

C5 is not there to eliminate highs at the input. It is there to block RF from entering the amps circuit by creating an ac ground to chassis directly at the input. You see these caps in amps that have isolated input jacks / star ground to chassis. That's what I suspected the purpose was. I edited th...

Make sure you try many deep cabinets. The owner has an EV12L in a shallow Fender 1x12 and it sounds like an AM radio. A very clear AM radio, but zero extension. It works pretty good with a Marshall 800 4x12. Mine sounds pretty good with my 12" closed back ported cabs. Works well with my 2 12" Fende...

I did one of these. We swapped all the resistors and caps and tubes and pots and the ot. It is still an unremarkable thing. heh It is better but.. I saw some of your posts. Thanks for all the work you put in! Bang for buck is pretty good in one of these. I haven't been spoiled by playing a real dum...

C5 is not there to eliminate highs at the input. It is there to block RF from entering the amps circuit by creating an ac ground to chassis directly at the input. You see these caps in amps that have isolated input jacks / star ground to chassis. That's what I suspected the purpose was. I edited th...

1) Eliminate C6 - RF filter. I thought these caps might eliminate highs at the input. I am a fan of simple and these simply aren't needed IMHO. 2) Replace C9 with a 390p - More mids in the treble circuit like the original #183 3) Replace C1 with a jumper - This cap filters out low end going into the...

I recently picked up a VHT D50 for an excellent price. I knew lots of people were doing various modifications to these amps to bring them more inline with a Dumble clone. I was looking for the most bang for your buck kind of mods. I thought it was quite likely others would want something similar so ...

What would be the Advantages/Disadvantages to using a Power Supply Choke in an 5F2A (Tweed Princeton) SE circuit?

The only disadvantage is added cost. The choke is a big help to tame the hum as Firestorm mentioned. I added an additional filter stage (with choke) to mine and it's dead quiet.