I have a little thread on this over at AK but since we are talking Dynaco....
Picked up the unit several months ago in basically original condition as it was packed away in a box in the late 80's until I opened it. great condition.
Initially brought it back to life slowly via variac at my techs place and used it a bit before I started getting various popping and distortion.
Ended up that several of the tubes had or were failing including one of the EL34's, both 7199, and the GZ34. Suddenly my investment was increasing to say the least as I wanted to try and stick with Old stock type tubes to keep this baby as original as possible. The existing EL34's are XF2 Mullards, the rectifier was an Amperex and the 7199's were whatever got the RCA brand. Doug at Dougs tunes came though for me on a matching EL34 and I went with a Japanese NOS mullard from Brent Jessie for the Rectifier.
In the meantime after reading all the great stuff on here as well as all the various other resources which are wonderfully available out there via the interweb, I went ahead and replaced the cap can (with increased values), all the caps up top, and used the Dynakitparts Bias kit to replace the S rectifier. All these parts I got from Kevin at DKP's and a big thanks to him for answering my newbie questions along the way. This was my first foray into working on electronics (I do some cap work on speakers) so I had plenty dumb questions along the way. I also went ahead and did the 7199-6GH8A conversion with the socket adpaters thinking while this was not "original" it sure made sense since it would be easy to go back to 7199's if desired. Dave G's Base line testing was a great reference.
I also did the rectifier diode mod per the sticky here.
Originally I thought I would have my local tech do this work, but he convinced me to go for it myself and save some $ since I had so many tubes to buy. Once done though I took it to him to check my work and test so we could bring it on line correctly. Viola! it worked great! At least until he went ahead and did a clipping test to see how strong things were. It unfortunately exposed that I have another EL34 that is weakening. Argh. It still sounds pretty good and biased fine so I guess I will go ahead and use it while I search for a replacement to match up with the replacement.
The one thing that caught my eye was a pretty brightly glowing Rectifier tube. Is this normal?
I have not hooked it up at home yet and plan on doing so today and will post my findings and maybe some photos. I have a restored to original Pas2 preamp I will be using with it and both Klipsch Heresy's or Altec Valencia B's are in the house, ready willing and able.