With a group, where a half dozen pairs will be wound the additional cost of an original( of what ever OPT is selected ) is not too bad. Some of the likely suspects would be the Acro TO-300, a 6k6 20W item, any of the 20W/5k Peerless 20-20 designs or OEM variants

For a PP 2A3 amp, operating at a SE-specified point( 2k5-5k SE load), anywhere between 5 and 10k a-a ought to work. The SE load mentioned in RCA data sheets is 2k5, and I would suggest a 5k or 6k6 for the project. Take a look at the E-Linear schematic I stuck somewhere( Tubes maybe?), and figure putting the 'screen taps' at 10% or so for just little bit of NFB. If we use a 5687/6H6-Pi or the like, it won't be much.

As to naming it( when it is finally done...) let's leave Merlin for a really advanced revision or another circuit. To mate with the Guinevere linestage, I would be suggesting Arthur of course.
regards,
Douglas

• Round Table Characters

I don't think I will be doing SE anytime soon either.

I have considered the 845 for the next amp, but *EVERYBODY* seems to have gone and built some version of an 845. Now the 813 is comparable in the filament requirement...and I have never even seen one built into an audio amp, let alone heard one. There are a few old commercial audio amps built with the 813. I suppose my statement ought to aply to DIY stuff.

if it were easy, everybody sould be doing it.
regards,
Douglas

Merry Christmas everybody!

I'm with you on the 845. To build one of those would just be so cool. Have a great Holiday......Colin