B-2 PS Fuses - Slow of Fast blow?

Thanks for the document - makes it idiot, er Uncle Paul proof. I plan on recapping/replacing diodes/transistors if the V-FETS are good. Probably will anyway as this one is cosmetically very good, and in the event of a bad V-FET would be looking for a donor unit. Having heard this one, I can't see doing without.

I do have the electronics training as a tech, but it was almost 20 years ago. I plan to build up to the B-2 by recapping an electronic crossover, then going through a couple of amps I have that need attention, then recapping an M-2 I just got. Mostly, just a bit of refresher to retain some skills like desoldering and soldering, use of test equipment, etc..



Makes sense. I figure if the V-FETS are good I'll start with the transformers and work forward.

Thanks tremendously for your input and suggestions!

So are your fets still good ?
 
I think I'll spend some time with my B-2 tonight. It needs a deoxit job as one side cuts out. The last time it was the DC switch on the back.

I'm also thinking of moving it upstairs to my home office. It would live under my desk and drive RayW's custom build, sort of a larger Indignia with ribbon tweeters. I'd have to cut the gain way down but my F5 just throws off so much heat.....
 
I think I'll spend some time with my B-2 tonight. It needs a deoxit job as one side cuts out. The last time it was the DC switch on the back.

Definitely the most annoying part of the B-2 is when the switches, attenuators, and/or the protection relay start to crap out. :thumbsdn: The good thing is it's usually an easy fix. :thmbsp:
 
Resurrecting this thread to give an update on the replacement "bow tie" PCB's. I never got around to pictures of the final product and now that I have that B-2 in teardown I took a few comparing an original to my copy. There is a fair amount of distortion, but all lines that are supposed to be straight really are.

upload_2017-2-6_12-18-0.png
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A couple of notes
  • Despite having measured at least a dozen times the new boards are about a mm shorter than the original. It's well within mechanical tolerances and as you can see fit just fine.
  • The molex type connectors soldered to the original PCB were not only soldered, they were also glued. To get them off I had to break away the old broken PCB and then use an exacto knife to clean off what I couldn't break off.
Since the place that makes the PBC's sells them in in lots of three, I have two left over. If any of you has a broken board I'd be happy to send you one of my spares. I can also make them available as a public project at OSHPark if you would like to have them made directly.
 
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