Tubes Asylum Questions about tubes and gear that glows. FAQ

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Tubes Asylum ]

---

[ Alert Moderator ]

---

RE: Fisher 800-C questions (newbie)

Posted by dls123 (D) on June 30, 2008 at 14:08:47

In Reply to: RE: Fisher 800-C questions (newbie) posted by Larry1304 on June 30, 2008 at 08:07:09:

Hi
I know Mike and Eli have given you good advice. I have done a lot of work recently on H-K Citation I preamps, Cit. V and Cit. II amps. I also restored a Sansui 1000a receiver. It sounds like your tech put in supplemental power supply caps - to me that means that rather than search out replacement cans (if that is what is in an 800C) he wired some caps underneath in parallel. He also changed a resistor or two. If it were my amp I would replace all the coupling caps, all the power supply caps, change the grid resistors (there are only 4 of them, it can't be that hard and they only cost a dollar or so each). There must be caps on some sort of feedback loop and I would change them too. I would also test every resistor in the power suppply section and replace as necessary. They are pretty darn cheap. I would test all the tubes. I would expect that most of the tuner section tubes are just fine. I don't have the schematic in front of me, but if it has 12ax7, 12au7, or 12at7's in the preamp section it is quite possible they are fine too. I would expect that the power tubes are probably about done. Possibly the driver tubes as well - don't know the circuit. It's only about $80 or so for a quad of new EH output tubes. Setting the bias is no big deal. You need to find a tech that takes vintage equipment seriously. I would do it for you, but you don't want to be shipping big heavy things across the continent. Try contacting your local hifi group. There has to be one. Some sort of club. Try googling or asking on here in the vintage asylum. You will sooner or later find someone like Mike or myself who will tackle it for you for the cost of parts and a few hundred dollars labor. It is a nice piece that needs to be restored. The power supply and coupling caps are probably about done. The parts are not that expensive, but you don't want to just throw new output tubes in without making sure the power supply and coupling caps are up to snuff. Even if your problem is the output tubes, if you change them your coupling caps or power supply caps will probably fail sooner or later. Don't worry, you will find someone who enjoys working on vintage equipment if you dig around a bit. Boston is a big city! As for cost...the full complement of caps must be available for $75 - $150 - I think there was a fisher restoration kit being sold somewhere - google it. It will have all the caps and resistors you need probably. The tubes - probably $80 - $150 depending on what you need besides a quad of output tubes. The labor.. well a shop would probably charge you $75/hour and you are probably looking at 4 hours or so? Never worked on a Fisher receiver, but that Sansui was a bear. But if I had to do another one I could be pretty quick, so if you found someone familiar with Fishers I bet 3 - 4 hours is a reasonable bet. Or put it on ebay and find a rebuilt Fisher receiver or one of the many other fine vintage units out there. The long and short of it is that you could put $500 - $600 into it and have a restored piece that could be good for another 20 or 30 years - with the change of power tubes every 5 years or so. It will sound way better than most modern stuff!
good luck!

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---