I'm far from qualifying a favorite here, but I can say that I have lived with 50 watt P/P zero feedback EL34 monoblock amps for about three years now. Mine are AES Sixpacs that came standard with Ruby brand EL34 output tubes. I understand Ruby to be a re-brander, so I'm not sure who the actual stock tubes were made by. I also tried a matched set of EH EL34's. I can't say that these were any better than my stock tubes, perhaps different is the better word. I believe the EH brand have a little more extension on the top, they sounded OK to me, but no real improvement. I then tried a matched set of SED Winged C EL34's from Upscale Audio. I can say that these definitely have more sweetness in the mids with as much extension at top and bottom that I have heard in my amps.
I'm not deeply familiar with your amps, but with mine, the input tube is a 12BZ7 that I was advised to consider rolling to a NOS type. I did this years ago and was amazed at the improvement in sound with this little tube, more clarity and detail was the result. Perhaps you have a similar situation with your Dodds, I don't know. Perhaps other owners or Gary could direct you with this one.
I too would like to try out a set of JJ KT77's as some report they have the detail and increased extension that I'd like to try. I read an awful lot on quality issues with these (poor solder joints, crooked bottles, thin pins) I'm not sure I'm ready to go there yet, more reading to do.
Regarding sources, while I'm sure there are many, I can recommend Upscale Audio for your matched set of SED's. They are cometitively priced and they are well known for their tube experience. One last thing, both my stock Rubys and EH EL34's held the bias fine, but the SED's are rock steady out to the third decimal on my meter, I'm not sure how relevant that is, but I thought it worth mentioning. Enjoy the new amps.
I'm not deeply familiar with your amps, but with mine, the input tube is a 12BZ7 that I was advised to consider rolling to a NOS type. I did this years ago and was amazed at the improvement in sound with this little tube, more clarity and detail was the result. Perhaps you have a similar situation with your Dodds, I don't know. Perhaps other owners or Gary could direct you with this one.
I too would like to try out a set of JJ KT77's as some report they have the detail and increased extension that I'd like to try. I read an awful lot on quality issues with these (poor solder joints, crooked bottles, thin pins) I'm not sure I'm ready to go there yet, more reading to do.
Regarding sources, while I'm sure there are many, I can recommend Upscale Audio for your matched set of SED's. They are cometitively priced and they are well known for their tube experience. One last thing, both my stock Rubys and EH EL34's held the bias fine, but the SED's are rock steady out to the third decimal on my meter, I'm not sure how relevant that is, but I thought it worth mentioning. Enjoy the new amps.