01 April 2014

Peavey Vypyr 75 Repair—Bad Name, Bad Design

I saw a non-working Peavey Vypyr 75 (seriously with the name?) at Guitar Center and couldn’t resist. These amps sell for $300 new and $150-$200 used, so I thought $80 was worth the gamble.

The main reason I took a shot was that it didn’t turn on. If something turns on, but doesn’t work, that can get pretty complicated, especially in a modelling amp. But if something doesn’t turn on, the possibilities are narrowed considerably.

And I was right—I quickly checked for anything obvious and saw the fuse, so figured I’d check that first.  I checked for continuity and there was none. I did not take an pictures, so here's a hastily made layout showing the location of the fuse. This diagram is pretty primitive, but there's not much to this amp, so if you can't find the fuse based on this, hie thee to an amp tech.



I quickly found the part I needed on ebay: 3-Amp 250-Volt fast blow fuse with axial leads for about $5, free shipping.

3A 250V axial lead fuse


The only minor pain was that this fuse has axial leads that are soldered to the board. You can’t just pull it out and pop in a new one—you have to remove the board, desolder the old one and solder the new one in. Well designed amps—of which there are many—have a fuse holder that is accessible on the back of the chassis, affording the owner the luxury of changing a fuse in a half minute instead of a half hour.


However, since I sold the amp for $140 a couple of weeks later, the time spent on this poorly designed beast was worth it. To be fair, I played with the amp for a while and had a lot of fun with it. It's a fun toy, but Peavey needs to head back to the drawing board.

17 March 2014

Biyang Fuzz Star FZ-10 Repair

I did this one for squeaks and gigs. I knew it would not be worth much even after I fixed it.

It was quite a mess when I opened it. The six pins that connect the two boards were not even in the holes, and several solder pads were missing, most likely the result of the previous repair attempt.

I did the following: 
  • Removed the six pins and replaced them with wire
  • Used a razor to expose some of the copper traces adjacent to the missing pads and placed mini-jumpers from the wire to the exposed copper
  • Put two longer jumpers where there was no room to expose the adjacent copper trace



Ugly, but it works and the connections are solid. Again, it’s not worth much, but because I often repair pedals that someone has already tried to repair, I see a lot of lifted pads and traces, so the practice was good.