FISHER all-tube receivers from 1961-66 are cheap and sound wonderful!

I have a growing stash of 7868s (quads and pairs of RCA/Sylvania/GE) but no gear to try them out. I also have some 7591s socked away with the same problem - I’ve never gotten to listen to any of them.

 

Have you heard that if you run EH power tubes you can’t go back to NOS because the sockets get stretched out? I’d like to get a quad of RCA’s for my 400 but I don’t want to tighten sockets.

 

I picked up this receiver as part of another purchase and never used it. At one point I hooked it up to a DBT and it tested ok. After powering it up normally at first it seemed ok but when I attempted to switch the input selector knob something went wrong inside. @action pact recommended Mike Urban to me and that's where I took it. The following was done to it;


#2940 Kenwood KW-60

Receiver (power supply, amplifier, preamplifier, & tuner)
Troubleshoot & locate open B+ dropping resistor, 1K ohm 2W wire wound
Replace failed coupling capacitors, (2) 0.022 & (2) 0.005 uf
Install silicon diode bias supply, (4) IN4002
Clean all controls & switches
Tuner alignment for best reception
Test all functions

 

Fisher 500-C vintage stereo receiver Page 2

Im guessing this Stereophile review has been posted here before, but I just reread it and figured Id post again for those who may have missed it.

I love my 500b. Its what got me back into listening to music and really enjoying the sound. I have a bunch of other equipment, but the Fisher is my favorite by a pretty wide margin.

 

Fisher 500-C vintage stereo receiver

Here's page 1 ... .sorry.

 

question to the group, has anyone switched from Electro harmonix power tubes back to vintage and had any trouble or success?

 

Yes...just did it. EH 7591 back to vintage RCA's. No issues at all.

 

Thank you! How did it work out? Did you like the RCA's much more?

 

To be honest, I'm not sure I hear much of a difference with the output tubes. They both fit the sockets without an issue. The EH has a bigger bottle, but still fit fine. I run 500b topless, but thought I heard the EH fit with top on too.

Regarding ancillary tubes, I like vintageTelefunkens in my phono stage. They sound better than brand new Mullards.

 

If you’re looking at trying out some U.S. made 7868s I can be of help (shoot me a PM).

 

Electro Harmonix 7868's use the euro Magnoval base (B9D), which do fit the Fisher 400 Novar (B9E) sockets, but have thicker pins that stretch the contacts out. This almost always ruins the sockets for the original 7868's with thinner Novar base pins.

If you have EVER used the EH 7868 tubes in Novar sockets, you're stuck with them unless you replace the sockets. And finding Novar sockets used to be very, very difficult (or expensive); after I scrounged for a couple of years grabbing every onsie-twosie I could find, they seem to be more available on that auction site now. If you want some, grab now.

 

I have a 500c. I went from EH 7591 to NOS RCA 7591 (made by Sylvania) and went back to the EH because I found them to sound grainy compared to the EH. After extensive listening tests (and adjusting bias) I believe the EH 7591 sound much better than RCA branded Sylvanias (In the 500c). I had a few extra NOS RCA that I switched in and tried too, so it wasn't just a bad set. I paid a small fortune for all the NOS tubes and resold them. Just my opinion, obviously. I have been told that the RCAs do sound better in the 500b.

 

I think the EH tubes sound fine. I bought a quad about 2 years ago when one of my RCA' s blew.

I bought one rouge RCA recently and put 4 RCA's back in.

I really don't hear any difference between RCA and EH.

 

Thank you, I thought that was the case. We clearly have some people that have successfully done it so perhaps it isn't guaranteed in every case. It feels like an expense gamble to find out. I have only heard EH in my 400 and I think they sound fantastic, when I put new ones in to replace the old ones it sounded like a new amp. I wonder if sometimes people are confusing the benefits of a stronger tube to that that of a vintage tube. I do prefer my KX-200 and they have Fisher branded (I assume Sylvania or RCA) power tubes. Hard to say its the vintage tubes that make it better since they are different tubes in different amps.

 

Since I have no way to test the Vintage RCA'S so I really have no idea of what life is left in them. One is slightly brown on top...this indicates its going bad. The other 3 look fine.

The EH's were bought new so my assumption is they would test strong. Again, without having them tested, it's an assumption.

Based on that, I don't know if I'm comparing apples to apples. Lucky for me both sets sound very nice to my older ears.

 

I use the EH tubes in my Fisher 400 receiver. Sound fine to me!

 

I think the EH 7591 sound very good in my 500b.

Unfortunately 1 of my quad tested very low so I put the vintage RCA's back in. They tested strong and were a close match too. Tech said they had another year or 2 left.

When they crap out, I'd probably buy a matched quad of EH's. Unless I fall into a matched quad of vintage for a good price.

 

I use a matched quad of the new tung sol 7591 from Jim McShane they sound every bit as good as the Westinghouse 7591 tubes that I had in and now have in reserve.

 

I raising car registration and rent May part with my 500c soon unfortunately. What do the go for now working with bad on off switch?

 

It’s a really wide range of prices. Anywhere from $500 to $1200.

 

I’ll aim medium and take low!


I think what I like is a tube preamp and a solid-state amp with a lot of power.

 

That’s good to know about Tung Sol vs. WH 7591 tubes. I put the Tung Sol 7591 quad in my 800c and think they sound great too. Mine had a quad of Electro Harmonix 7591 in it when purchased. I discovered after switching to the Tung Sol that the EH tubes were pretty well shot and we’re what was causing lots of distortion, best $106 I’ve spent in a long time!

 

If you 500C has been restored and in good condition it should be worth $1k, or a minimum of $800. If you have a case for it, the case will add $100 to $200.

Unrestored in average condition, $600. It nice condition maybe $800.

 

I play my 400 regularly.

 

I restored it myself and only almost
Got electrocuted once. All the things that need swappin’ were done.