Output issue with Ruby Amp

Started by CJPreston, November 02, 2013, 03:26:58 PM

Previous topic - Next topic

CJPreston

Good Saturday afternoon DIY folks -

Having an issue with the ruby amp. here are the voltages at the eight pins:

1. 1.318
2. 0.5
3. 0
4. 0
5. 9.98
6. 10.56
7. 5.35
8. 1.318

I get a faint very distorted sound at the speaker level. 8 ohm speaker from an old fender frontman. The issues seems to surround the 220uf. I've tried two different 220uf electro caps and the same issue happens.

When I've placed a probe in front of the cap directly to the tip out to the speaker i get the "normal" volume but very ugly sound from the amp and when I come back out the (-) side of the cap I get almost a distorted whisper of audio or no audio at all.

I've bread boarded this circuit twice and it has worked fine but when I put it on pref board i get this issue.

Any thoughts on what the problem is?

If I need to provide additional information please ask. I am new to this arena of electronics.

Thanks!

CP

Also - I used the pcb layout as designed by Pablo De Luca (aka Gringo) from runoffgrove.com. http://www.runoffgroove.com/ruby.html  I did run continuity tests to ensure there were no solder bridges to areas that were not supposed to be connected.

PRR

Pin 2 should be at zero, not 0.5V

Figure out why that's wrong. Leaky or reversed cap from the preamp?
  • SUPPORTER

CJPreston

I just rebuilt using new JFET and 386 and had success...not sure what the issue was...