sho problems

[ninjadave7]

Hey all,
I recently built a sho clone and it spent a year working really well until last week, when it started to cut volume slightly, and dull the signal a bit.  It also produces a high pitch sound, almost like it's oscillating.  I replaced the transistor (a bs170) to see if that made a difference, but nothing.  Any thoughts?  It's a very simple circuit, but I'm just learning some of the basics of electronics, not that good at troubleshooting yet.

http://flic.kr/p/aFsd9p

[StereoKills]

Are you running it on a battery or wall wort?

[ninjadave7]

i've tried it on a 1-spot and on my PP2+, and tried different cables, straight to amp, after buffer, etc.  I feel like I've ruled out those possibilities, but maybe not?

[ninjadave7]

any help?

[chromesphere]

Hi Ninjadave,
If i were you i'd cut the board out of the enclosure (in, out, 9v, and ground wires) and test it externally from the enclosure to isolate if the problem is on the board / circuit or in the wiring of the enclosure.  I know it started out of the blue, I've had boards do this and found that the problem exists on the baord (solder joint, lose wire, etc). If you find it isnt the circuit, then you can look at the wiring of the enclosure, and its easy enough to just solder the four wires back into the enclosure again.  This is the process i usually do for faulty completed builds.
Hope that helps and good luck.
Paul

[ninjadave7]

Thanks Paul, just got time to start fiddling again so I'll try that!

[PRR]

> working really well until last week, when it started to cut volume slightly
> I'm just learning some of the basics

When a working circuit goes bad, 90% of the time it is a bad joint; 99% if the builder has not yet perfected his soldering craft.

Take it out and study it under a bright light. If you are over 25, use a magnifying glass.

[scuzzphut]

Also worth checking the cleanliness or otherwise of the contacts on your jacks.