I've restored 2 400s, wonderful sounding amps but a fair amount of work. I came across a stripped down 500B for a great price. I took a look inside and thought it might be easier to work on than the 400s, and the amp was bone stock so I didn't need to trace down old repairs issues (+ original Ero-Fols 
).
I should've known better.
Did the usual cleaning, checking components, testing tubes, clean faceplate and new lamps. Had to jumper the Reverb In Outs and the remote socket. Slow warmup on variac and amp sounded good, though no FM at the moment. 2 knobs from a later Fisher. Ordered parts. Receiver was missing the EM84 but worse the mount for it. Borrowed one from a 400 for the moment, as well as a tube or 2. Looking good already!
Started the major work yesterday and I always like to start from PS. I'm not a fan of the work of restuffing cap cans but it makes the most sense for the price and look. I managed to get 2 new from CE but 3 more cans will need replaced. (as with almost every Fisher I've seen the 1000uf PS caps were almost 50% over). Restuffing is a bit like plumbing work. Messy, toxic and very slow to not destroy the cans and clean them out. Of course they also need some shine. Most of todays work was removing, stuffing and cleaning, and then replacing the rectifer. The clincher here is 5 cans that need removed, carefully, as they are loaded with components and those mounting tabs or the phenolic are very fragile. Small rip in the cardboard sleeve for the 200uf.
Went in this evening with the big iron to remove the remaining cans. Desoldering those ground lugs, in the tighter area, started to make me second guess this whole endevour. Too. Many. Cans. with Too. Many. Components. For some reason, Fisher decided to run the whole circuit through one 50uf cap! Visions of the Cross Bronx Expressway on a Friday, or the Panama Canal, flashed before my eyes. The employee who did this work was clearly was was looking for a raise. Each lead triple wrapped around each connection. I've only had one other amp with slightly more complicated wraps/solder which was a Scott 299. Phew, so hard to remove components without damaging.
Let's count: 4 resistors (of almost every type), 2 leads and a ceramic disk leg all on one lug! Had to use the big iron to desolder this one, which of course melts the wire sleeves. That .02 cap had also given up some time ago and also measured 50% high. The glass resistors don't seem to like the excess heat ( I had a pair burn up in a 400), they'll get replaced anyway. This is the point I also begin to question why not just snip off the old leads and tack solder instead of slow removal, and cleaning each connection with ISP before installing new?
The clock begins to pinwheel. Did I leave the dog in the yard 8 hours ago? Will I emerge from the basement to find the wife and kids moved out? What year is it?!!!
Maybe I can take a break and listen to some vinyl.... nope.
I am reminded why I shine up the can caps, with hopes that the dazzle with help forget that 50uf connection!
Needless, when I have time to take a break, I have to write a lenghty post about the Fisher. Perhaps I need an intervention to get rid of the completist that the 500b demands? More visions of all the dudes I bought this stuff from who had piles of unfinished projects in their homes.
Fellow Fisher enthusiasts, pls remind me the hours spent will be rewarded the 500b being so good it sounds like a small chamber orchestra playing in the room. Or that the one less unfinished tube amp equals equilibrium on a cosmic level. In the meantime, I'll wake up tomorrow without being able to ignore the remaining cans, thermistor, the bias test points and grid resistors, phase inverter, the MPX, the loudness, and the IBAM. If I wish to sacrifice 3 more days, I may try and tackle the RIAA and Tape Head on the switch.
Did I mention I have a case? (needs sanding and restaining)............
).I should've known better.
Did the usual cleaning, checking components, testing tubes, clean faceplate and new lamps. Had to jumper the Reverb In Outs and the remote socket. Slow warmup on variac and amp sounded good, though no FM at the moment. 2 knobs from a later Fisher. Ordered parts. Receiver was missing the EM84 but worse the mount for it. Borrowed one from a 400 for the moment, as well as a tube or 2. Looking good already!
Started the major work yesterday and I always like to start from PS. I'm not a fan of the work of restuffing cap cans but it makes the most sense for the price and look. I managed to get 2 new from CE but 3 more cans will need replaced. (as with almost every Fisher I've seen the 1000uf PS caps were almost 50% over). Restuffing is a bit like plumbing work. Messy, toxic and very slow to not destroy the cans and clean them out. Of course they also need some shine. Most of todays work was removing, stuffing and cleaning, and then replacing the rectifer. The clincher here is 5 cans that need removed, carefully, as they are loaded with components and those mounting tabs or the phenolic are very fragile. Small rip in the cardboard sleeve for the 200uf.
Went in this evening with the big iron to remove the remaining cans. Desoldering those ground lugs, in the tighter area, started to make me second guess this whole endevour. Too. Many. Cans. with Too. Many. Components. For some reason, Fisher decided to run the whole circuit through one 50uf cap! Visions of the Cross Bronx Expressway on a Friday, or the Panama Canal, flashed before my eyes. The employee who did this work was clearly was was looking for a raise. Each lead triple wrapped around each connection. I've only had one other amp with slightly more complicated wraps/solder which was a Scott 299. Phew, so hard to remove components without damaging.
Let's count: 4 resistors (of almost every type), 2 leads and a ceramic disk leg all on one lug! Had to use the big iron to desolder this one, which of course melts the wire sleeves. That .02 cap had also given up some time ago and also measured 50% high. The glass resistors don't seem to like the excess heat ( I had a pair burn up in a 400), they'll get replaced anyway. This is the point I also begin to question why not just snip off the old leads and tack solder instead of slow removal, and cleaning each connection with ISP before installing new?
The clock begins to pinwheel. Did I leave the dog in the yard 8 hours ago? Will I emerge from the basement to find the wife and kids moved out? What year is it?!!!
Maybe I can take a break and listen to some vinyl.... nope.
I am reminded why I shine up the can caps, with hopes that the dazzle with help forget that 50uf connection!
Needless, when I have time to take a break, I have to write a lenghty post about the Fisher. Perhaps I need an intervention to get rid of the completist that the 500b demands? More visions of all the dudes I bought this stuff from who had piles of unfinished projects in their homes.
Fellow Fisher enthusiasts, pls remind me the hours spent will be rewarded the 500b being so good it sounds like a small chamber orchestra playing in the room. Or that the one less unfinished tube amp equals equilibrium on a cosmic level. In the meantime, I'll wake up tomorrow without being able to ignore the remaining cans, thermistor, the bias test points and grid resistors, phase inverter, the MPX, the loudness, and the IBAM. If I wish to sacrifice 3 more days, I may try and tackle the RIAA and Tape Head on the switch.
Did I mention I have a case? (needs sanding and restaining)............
