5F2A / 5F1 build w/ old OT and speakers, need advice

[Helmholtz]

I'd be inclined to use a low voltage PT and a 6V6 or 6K6 and the original OT.

Don't forget the cute 6AQ5-A.
But all these want an Ra of 6k or higher at a B+ of 200V.

The EL84 will accept a lower Ra (4.5k@250V).

[Chuck H]

Don't forget the cute 6AQ5-A.
But all these want an Ra of 6k or higher at a B+ of 200V.

The EL84 will accept a lower Ra (4.5k@250V).

How about a 6V6 operated as a triode.?.

Of course the el84 is a fine suggestion.

[Helmholtz]

No experience with SE triode output. Might sound rather stiff with guitar.

I think an EL84 with a B+ around 200V should work fine with the existing OT and speaker.

[35L6]

The radio has series heaters so you need to use all the tubes or none . The pentagrid converter must be good for something but I don't know what . Perhaps just connect the heaters or replace with a power resistor . The IF tube and AF tube can be used for the preamp . The power amp can be used as drawn . The extra tap on the OT primary is a choke for the screen node , also use as drawn . Does this radio have a field coil speaker ? If it were mine , I would use a Triad N-68X or equivalent for the PT , hook up the AF tube and power tube as drawn and see how it sounds . If that is OK , download the data sheets draw load line and use the other tubes .

[boroman]

No, no... if it's so complicated, Ill use everything new but the wooden box and chassis (with new tube socket and all new circuit of course).
But the best would be using as above PLUS spekaer. If its classic impedance like 8/16 ohms it will be fun to use it and have a switch for output jack for regular guitar cabinet

[Mike K]

Mercury OTs for Champ are 8k for 5F1. 9k for 5F2A. I have seen other suppliers go even higher. Older, 5C2/5D2 etc were 6k. I had a Heyboer that was somewhere around 6k (champ size) but it looks like they are 5k again now.

IMO the higher impedance, the better they sound. 9-10k being pretty optimal for a SE 6V6. I run SE EL84s at 12k - they sound great provided you have enough screen capacitance to keep up. I've been running a JJ like this for about 3-4 years now, I haven't toasted the screen.