The Amp Garage

i wouldn't remove a thing,just rewire the pot such as its on max value,so remove wire from pin 2 and solder it to pin 3 along with the existing wire,it should be ok.

jcsifu wrote: ↑Fri Oct 18, 2019 11:59 pm What happened under that 10w 620 sand resistor?

power of boutique

if the effect is distorted you need to attenuate more in the send,i guess the mojotone used a 20x divider,don't know what you have in this,it looks like a new model.
Probably it just needs a divider with a couple of resistors between treble wiper and the loop

you have the amp,draw it yourself,otherwise its impossible to assume any cause.

A schematic could be useful

the point with VVr is that if you scale all the amp,the preamp will sound bad and you need to block DC coming out of the grids,if you scale just the PA you need a simple MV in front to keep the ratio. And yes,once again,PPIMV less than half sounds like ass,just look at it on a scope and you figure w...

what speakers are you playing through? JCM800 are very bright and thin if not played full gain. If you think there is an oscillation,just put your scope probe across the speaker,respecting ground connection,and you'll see any HF oscillation. Cathode bias is not the best for punch,it has the tendency...

its running,i guess there is a question to answer for registering

Sozo on tonestack and after PI

nice amp!

That 4,7u cap i guess bypasses the 10k cold stage,that easily creates oscillation,i would try a snubber on the respective anode resistor,470p/1n should be ok.
The loop is ok placed between the treble wiper and the MV,maybe it needs a bit of attenuation on the return stage.

Thanks Steve we need one of your cool circuit pages on this. Changed layout to reflect discussion. Remember guys I am terrible at Visio as you can see. I took the color bands off the ones I don't have in my library rather then change the colors I got to get going so maybe later I can add back in co...

standby in GZ34 amp? useless and detrimental for the tube itself.
It can be arcing inside the switch or a tube,or a socket.

El84s have no problems at over 400V on plates,the only problem is if you feed the screen grids with over 350V. What i usually do is a zener follower after the first capacitor that feeds the plate,or a proportional mosfet regulator,that way i'm dissipating just the preamp and screen power,and i can a...

why not blocking new subscriptions for a month at least?
The only way to sort out all this bullshit is just give access manually at new users,after having answered correctly to a series of tech questions.