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In Reply to: RE: Fisher 800-C questions (newbie) posted by dls123 on June 30, 2008 at 14:08:47
'Replacing all the tubes' may mean, pocketing all the valuable Telefunken and Sylvania OEM tubes and putting in "new" but possibly inferior tubes, at great expense to you and profit to them.I restored my Fisher 800C myself, but I had 'some' experience. I got the booklet from Fisher Doc (not sure he's still in business). He recommends NOT replacing original PS capacitors unless it's necessary. Mine worked perfectly. We put the amplifier on a scope and the signal was about perfect, so I even left in the German-made coupling caps so as not to alter (screw up) the sound. YMMV.
I'm not saying techs are unscrupulous, but as you surmised, that may not be the place to go. You shouldn't have to ship.
Pete
- sold my 800C (shown), and the new owner loves it, works great almost 2 years after.
Edits: 06/30/08Follow Ups:
Hi
Certainly a very valid response, as I have no experience with Fisher receivers. I agree, if the power supply cans are OK, then leave them alone. However, if they are weak it shouldn't be hard to find new cans for $25 - $35 each that are of very high quality. I bet Jim McShane has some. The EH output tubes are $80 for a matched quad from Jim. I also agree that most of the small signal tubes are probably just fine. I just checked and there is a guy on epay who is selling the entire cap kit for $85. I have no idea how good the original caps are and what kind of shape they are likely in. I leave that to people with more experience on Fishers. If it were mine I would replace every cap and put Russian PIO's in for the coupling caps, but that's me. But output tubes and a cap kit are only $165 for parts. Labour simply can't be that bad. 4 or 5 hours I will wager. Biasing has to be pretty simple. All you need is a DVM and a screwdriver I am sure...... I would guess he could do it himself.
cheers,
Don
Don,
Biasing on Fisher receivers is truly fixed. :> ( There's nothing to adjust. You check the voltage and tweak parts, if it's out of tolerance. Truly fixed bias imposes the need to buy VERY closely matched quads of O/P tubes. All 4 "finals" must be extremely close in both cathode current and gm. Yes, McShane can provide the sets needed, but he, or any other honest dealer, has to charge for the considerable work involved in the culling. Unfortunately, factory "matched" quads fail to "cut the mustard".
Eli D.
Hi Eli,
Wow, that seems like a pretty silly design. Still, I bet Jim doesn't charge more than an extra $20 or so to do it. If I had one of those Fishers I would seriously consider changing the bias scheme to at least a balancing pot on each channel.... Seems to me that even if you get a new quad that has been expertly matched there is no guarantee as to how far apart they will drift as they age. Of course I have a Sansui 1000a to fill my receiver need and the Citation II upstairs to REALLY listen to. I managed to score some EI KT100 type I's and am running it in triode. Very nice. I also have a Citation I and V combo in the basement that is sounding pretty good after all the McShane kits...... so I'd have to sell something to take on another project!
cheers,
don
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