I'm a Tube Guy Again - Fisher 500c

My 400C/SA300b pre/power barn finds didn’t look much different when rescued, maybe more cobwebs, and I was in just under two grand in tech bills before they were off and running. The most expensive audio gear is cheap tube gear if you don’t know how to fix….lesson learned.
This always leads me to wonder, at what point does a vintage piece of equipment become, to use a term form the classic car enthusiasts, a restomod? I see lots of new boards, change to circuits and other things on vintage gear restorations, and wonder does that effect value like it does with classic cars? I’m guessing it does.
 
This always leads me to wonder, at what point does a vintage piece of equipment become, to use a term form the classic car enthusiasts, a restomod? I see lots of new boards, change to circuits and other things on vintage gear restorations, and wonder does that effect value like it does with classic cars? I’m guessing it does.
I don't regret having that set rebuilt, though I wish I'd have used a different tech who actually -did- do a bit more updating to things, instead of trying as best he could to give the original sound. Which... was....a bit lackluster. I would guess that most anything wrong with this receiver is fixable, its just a matter of time and money.

I don't buy broken things anymore (I say that while knowing a neighbor has a pair of problem-child HPM-100s and a Sony receiver in his closet waiting to bring over here).
 
I had a 500C in 1970. It was one of my very first components.
I liked it but wanted more power. It was fairly quickly succeeded by a pair of Mac MC 40s and then Dyna Mk. IIIs, and a Mac C-20 preamp. Then the Mk III were replaced with MC 75s. In about 1973 good matched pairs of KT 88s started getting hard to obtain and transistor amps started sounding better. Actually good new 12AX7 and simlar dual triodes started getting a little harder to get though never as bad as KT 88.

I find it amusing when I hear that current tube aficionados like 6550s . 6550s are why I switched to solid state. The GE ones which were the easiest to get in St.Louis 1) didn't come in Matched Pairs 2)had crappy reliability failing with horrible loud lightining storms in the output tubes. and 3) Didn't sound as good as Gold Lion (real not fake gold lion) KT-88MPs which were overpriced even in 1972.

Macintosh would replace bad tubes in Macs for free. But soon they started using GE tubes and then quit altogether. I saw that coming in advance. Even though I was only about 20.
 
I try my hardest never to power up anyhting as old as a Fisher 500 with the original power supply caps in it. There ultimately is a fair amount of risk to doing this.

You'd want to open up the unit and measure the DC resistance between the B+ and each plate terminal of the output transformer to be sure they are somewhat close to the same value. You could also disconnect one HV lead from the power transformer to test the AC winding voltages.

No signal coming out of the speaker jacks isn't necessarily as big of a problem as blowing fuses. You or a tech will just have to feed in a 60Hz tone from a phone and follow it with a DVM or a scope to see where it drops out. That could be something as silly as a dirty switch that needs cleaning.
 
It’s honestly very rough looking and I’d have been surprised if it just fired up. I’m no tech but this looked like an overhaul from the get go. There’s a lot of parts out there thankfully!
It isn't rough looking at all. It's actually in very good condition. Just physically dirty. With a nice cleanup, it will look great.
 
It isn't rough looking at all. It's actually in very good condition. Just physically dirty. With a nice cleanup, it will look great.
Im just going by the photos. Heck I bring things up on a variac even if they’re mine and were working when I put them away. But I do know that you’re an optimist and I’m a pessimist:) After a nasty shock once I bring mystery (tube) machines to a tech without even attempting to power on.
 
After a nasty shock once I bring mystery (tube) machines to a tech without even attempting to power on.

I have certainly had my share. :D

Glad you are playing it safe John.

As I always consider, it only takes once...... please be careful guys.

cheers

pos
 
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I have certainly had my share. :D

Glad you are playing it safe John.

As I always consider, it only takes once...... please be careful guys.

cheers

pos
Yeah the chassis was hot on some old heathkit piece that I bought at a radio club flea market with no outlets but I was told it worked great. Yeah at shocking me. Learned my lesson. Honestly I didn’t know what I was doing. I run old tube gear occasionally but only after complete restoration.
 
In about 1976 or so I was working on a switched on Dyna Mk III. The B+was around 700 volts iirc. I got one had across some live points and I still remember it like it was yesterday. It hurt and I remember my hand trying to close fast. Fortunately I withdrew hard and didn't grip anything so it was just a bad memory. I already had proper respect for such things but it is easy to make a misteak.
 
Im just going by the photos. Heck I bring things up on a variac even if they’re mine and were working when I put them away. But I do know that you’re an optimist and I’m a pessimist:) After a nasty shock once I bring mystery (tube) machines to a tech without even attempting to power on.
I didn't power it up. I took it to the same tech who fixed the citation.
 
Ahh it read liken you flipped it on cold start.
If you go in to a unit like this; thinking full rebuild (if you want a solid and dependable unit), then it won’t be as discouraging when it doesn’t fire right up.
I am looking forward to seeing your unit up and running. :)
 
:redface: More things I should have learned had I been paying attention … Shamefaced, as many times as I have been (in awe) in the building I didn’t know until yesterday that the Fisher of Avery Fisher Hall was the founder of Fisher electronics. Fisher donated $10.5 million ($69 million today) to the orchestra in 1973. However, I did know - but had forgotten - that the Fisher company later became Emerson and then Emerson became Sanyo and then Sanyo became Panasonic. I didn’t know that “Fisher was the first to introduce stereo receivers with four channels. “ . (Wiki)
 
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Came out well. The poor X-11 doesn't get the respect it deserves. Now guys are dropping the bulletproof Cadillac 4.9's into them, and they become total screamers.




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We had a hand-me-down 1980 X-body in the form of an Olds Omega. In 1987, the second time that the starter fell off -- I decided it was time for us to buy our first new car! :)

On topic 😊 I am (EDIT) very sorry :( that the titular Fisher was, apparently, DOA. It wasn't clear, though, that "we" got too much insight as to its actual status. Lacking B+ or even bias supply voltage would result in a flatliner, but I am not sure that was tested. From my perspective, if the transformers are OK, there's hope. If even one is not, it's probably best viewed as an organ donor (or even as a carcass donor, because the chassis and panel are in pretty good shape).


All in all, though, my sense of guilt is assuaged, because, failing all else, the box is probably the most valuable bit! :)
I am - perhaps not surprisingly - reminded of Calvin & Hobbes.
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EDIT: Of course, in the case at hand, the box is wood-veneered plywood, so even cooler than cardboard.
I am thinking that cardboard and hot 7591A outputs might be a bad combination. :(
 
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