Volume knob acts more like a tone pot?

[Paultergeist]

Greetings,

I thought I would see if anyone else has been down this road before me....

Just completed the initial construction of a Rocket-inspired build yesterday. Upon initial start-up after checking voltages and looking for smoke, I plugged a guitar in. The the volume knob of the amp didn't seem to work correctly at first -- sweeping towards "off" made the amp only roughly 50% quieter and less bright ------ or at least so I thought. After maybe a minute of adjusting knobs and switches, the amp seemed to come alive, sounding pretty good and the volume knob behaved normally. I attributed the initial weirdness to some lapse of awareness on my part as to how it was set-up or to the break-in of the SoZo caps.

Went to play it again just now.......the strange volume knob effect has returned. Even with the volume turned all the way off, the amp is still significantly loud, but with a loss of treble. With the volume dimed, the amp is louder and brighter, but there is absolutely no distortion (actually, it is a very nice clean tone). This is different from yesterday, when the amp was going into break-up at higher volume settings. I have not changed a thing -- not even turned the chassis over -- between these two events, so this is strange,

I am pretty sure I am about to embark on a trouble-shooting journey, and I guess it is my time, as most of my previous builds worked perfectly from the start. I thought I would ask if anyone had experienced anything like this themselves, or had a guess as to what could be happening regarding the volume pot effect? I cannot see any issue with wiring......

Thanks for any suggestions.....

[pdf64]

My guess is that your volume pot has an intermittent ground connection.
It may even be a dodgy pot, eg terminal 3 not crimped on to the track properly.

I attributed the initial weirdness to some lapse of awareness on my part as to how it was set-up or to the break-in of the SoZo caps

Crikey, the above demonstrates how insidious such nonsense can be, that this poor guy can be under such a monstrous misapprehension that the impact of unbroken in caps can be as significant as an obvious fault.

Great result guys!
Pete

[Paultergeist]

Fixed. Bad tube socket. In fairness, I also had too much solder at a couple of socket pins, so maybe I caused or contributed to the problem. Anyway, I need to check the bias next......nah.....I'm just first going to play the hell out of it for a spell.....

.......sorry, neighbors.......

[sepulchre]

.......sorry, neighbors.......

Heh . .

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