New to tubes

[Jailtime]

I've currently got some nice solid state gear (fully restored Marantz 2235B), but I'm getting the itch to add a nice tube receiver to my audio collection. The Fisher 500C and 800C really caught my eye, beautiful looks. :drool: I've worked on my solid state gear a little bit, and I'm training to be an avionics tech for the USAF right now. I'm confident that I could recap a solid state receiver. So would minor work on tube gear be beyond my capabilities? I've got an eye on an 800C right now, but it blows fuses. Transformer, maybe? Thanks in advance for any tips! :thmbsp:

 

[kvflyer]

Go for it! Blowing fuses would most likely be the filter capacitors shorted or even the bias bridge (if the 800C has one). USAF trains you well; you can do it...

 

[kvflyer]

What is often the problem is:

Leaky electrolytic filter capacitors.

Leaky paper coupling capacitors to the grids of the 7591 output tubes.

If it has a selenium bias bridge, that may be weak or even open. I have not worked on Fisher much even though I have two 800B receivers. HH Scott uses a Siemens selenium bias bridge. That bridge also feeds DC to the filaments of the first preamp tubes in the Scott. If the bridge is bad, no preamp too.

If someone has not tried to horse this thing and put in a "NoBlo" fuse, transformers should still be good.

I think the 800C uses silicon rectifiers in the B+ so they may still be good. The Scott amps used 5AR4/GZ34 tube rectifiers; the 340B/345/380 used silicon rectifiers.

BTW, my cousin's son graduated from USAFA just over a year ago. I have been to USAFA many times. First rate. He is now flying the T-34C at Pensacola with the Navy for his primary flight training.