PSU or lead dress issue

[sixstringnick]

Recently put together a 4 watt 1 preamp,1 output tube single ended guitar amp build. 47uf/450v caps were taken out of a 2 year old build.They are the cheapest Sprague caps. Amp is oscillating,ghost notes and occasional tremelo's. Just wondering if this could be a PSU issue, or would poor lead dress cause these issues.I don't have an HT fuse in place, but will soon, as one sign of bad caps would be blown fuses. OT is very close to V2 output, not sure if this could cause issues. I've tried to create as many 90 degree angles as possible with lead dress. .Grounds clustered to respective PSU cap negative going upstream from PT-CT/OT output jack sleeve/Resevoir cap negative to star ground single chassis point near isolated input jack.

[MWJB]

We really need some pics to get an idea, a single ground point at the input, that connects to the speaker ground sounds like a bad idea. It is a good idea to use 2 ground points, one for power amp, one for preamp. Ground speaker out near as possible to speaker jack. Check pots & grounds are tight to chassis, check grid wires are short & don't run close to heaters & plate wires.

[loudthud]

Is there feedback (a resistor) from the speaker side of the OT back to somewhere in the circuit? Does the volume control affect the bad behaviour, that is, does it sound ok as you first turn up the volume control and then you get to a certain point and it goes crazy?