jtcnj
Ambassador of the Crossroad
So, after troubleshooting, the conclusive assessment has been made with certainty I experienced my first power tube failure due to the tube just being worn out.
I had a defective 6L6GC fail through the screen shorting once early on.
The Tweed Champ clone build I have featured here often is a 5F1 circuit with the Princeton 5F2A tone pot, switchable v1a bypass cap for 25µf / none / 0.47µf, and a pot on the NFB circuit.
Not pretty but brings the goods.

The tubes are a Sylvania used / old stock 12ax7, current production Tung Sol 6v6gt and JJ 5y3.
The speaker is Weber Sig8 ceramic.
I ordered 3 6P6S Russian military surplus tubes that are similar enough to the 6v6gt to be called the "same", a while back.
I put them in and played them when I got them a few minutes each to verify they work and noted they sound ok without really working them out in detail.
Similar to these I just ordered:
I swapped between the old Tung sol - (it plays but has shooshy sounds and some popping sometimes)
a JJ 6V6S pulled from my 5e3, and the 6P6S. Swapped the tubes as soon as it cooled down enough to handle.
They all sound very good to me; slightly different from each other but happy with either of them. the JJ sounds a little bright / harsh in OD but smooths out with either amp or guitar tone pot.
Just my $.02.
I had a defective 6L6GC fail through the screen shorting once early on.
The Tweed Champ clone build I have featured here often is a 5F1 circuit with the Princeton 5F2A tone pot, switchable v1a bypass cap for 25µf / none / 0.47µf, and a pot on the NFB circuit.
Not pretty but brings the goods.

The tubes are a Sylvania used / old stock 12ax7, current production Tung Sol 6v6gt and JJ 5y3.
The speaker is Weber Sig8 ceramic.
I ordered 3 6P6S Russian military surplus tubes that are similar enough to the 6v6gt to be called the "same", a while back.
I put them in and played them when I got them a few minutes each to verify they work and noted they sound ok without really working them out in detail.
Similar to these I just ordered:
I swapped between the old Tung sol - (it plays but has shooshy sounds and some popping sometimes)
a JJ 6V6S pulled from my 5e3, and the 6P6S. Swapped the tubes as soon as it cooled down enough to handle.
They all sound very good to me; slightly different from each other but happy with either of them. the JJ sounds a little bright / harsh in OD but smooths out with either amp or guitar tone pot.
Just my $.02.
Last edited: