Amp build humming no matter what

[Soma89]

Hey there, first poster here.

I recently "lucked out" and traded my functioning amp for a homemade Deluxe Tweed head with issues. Was like this since I brought it home. Seller said he doesnt know what I did to it so not claiming responsibility..he said it worked fine when he had it (absolute bs)
Tubes in amp are
12ay7 12ax7 6v6s 6v6s 5ar4(supposed to be a 5y3 but told this wouldnt hurt)

I was told its a tweed deluxe clone. Only 2 inputs instead of the original 4.
Here are the problems...

**Humming when volume is at zero w/ no instrument plugged in on both inputs

**Humming increases with volume. Tone knob changes pitch of humming, from very bassy to bright and overly buzzy. I believe it to be a 60 cycle hum.

Heres what I've tried to remedy the issue...
-Replaced preamp tubes.
-Moved all the previous grounds to one ground @ the volume pot.
-Recapped (amp used to pop when tapped with chopstick..this fixed that mostly..but still loud hum remains)

*This thing is not for the faint of heart. Wiring is very messy.
Also volume goes from ZERO to HERO really quick on the dial (probably part of the circuit?).

[Colossal]

The right-side lead of the ceramic tone cap appears to be touching the front panel of the chassis. Maybe the left side too.

[xtian]

Welcome!

That looks...terrible. One leg of heater grounded to chassis. Too many other issue to list. I'd tear everything out and start fresh.

[Colossal]

Welcome!

That looks...terrible. One leg of heater grounded to chassis. Too many other issue to list. I'd tear everything out and start fresh.

I would have to agree with that assessment That floating fuse holder....

[Soma89]

I was thinking of doing just that, sadly..

One thing though, the old caps that were connected to the power tubes were old and showed resistance when I measured across them. Could this have damaged the 6v6 power tubes and perhaps be causing the hum?

** I've only recapped tube amps in the past but dont know much "tube amp building theory" other than the basics if you guys have any pointers for when i start the new wiring, please let me know. Problem is that I'm stuck to working with this chassis which may not be the greatest.

[EL504]

With the exception of the grounding of the secondary of the OPT, I never use the chassis for earth returns. I wire pretty much all earth returns to one central earthing point close to the instrument input(s). I connect the earth/ground lead from the AC inlet also to this point (and to nothing else).

Although I can't be sure that this practice guarantees a hum-free build, it works great for me because none of my builds had hum problems, including the amplifiers without dc-heating of the input tube(s).