another take on Ruby amp Problems : )

[bloodmist]

Hello.
This is my third post on this problem : ) but now I have the multimeter and can measure things : )
Project: Ruby amp.
Links:http://www.runoffgroove.com/ruby.html
http://www.generalguitargadgets.com/index.php?option=content&task=view&id=213&Itemid=238
Modifications: 5k pot for gain instead of 1k. a LED to show when its on. and the stereo input on/off switch thingy...
Problem: plugin small headphones- no problem. no problems with volume.
plugin big over-ear ones and as I raise the volume, suddenly loud squealing kicks in. if I try to play with it (the squealing), the sound is distorted and blended into the sqwuealing.
plugin electra distortion before the amp and there is no sound at all.
plugin electra after and the sound is really quiet.

this is my first time seriously using a multimeter. it's analog. If any more measurements are needed, please tell me, because I just included the IC and transistor since there are no diodes or zener thingys.

battery: 9v
red: 8.6v
black: 0
IC1 (LM386):
P1=1.2v
P2=0
P3=0 ground
P4=0 ground
P5=3.6v
P6=8.6v
P7=4.2v
P8=1.25v

Q1 (MPF102):
1(drain)=8.5v
2(source)=1.5v
3(gate)=0

I think I actually included all the info I have this time : ) except for the pictures.
so is it supposed to be possible to run Ruby(battery) and an effect(another battery) somehow together?

[fixr1984]

Im not much for de bugging things myself but your tranny voltages look bad. Do you have it in the right way? Thats where i would start first.

[bloodmist]

tranny meaning transistor?

also is the 2nd pin of the IC supposed to be 0?

[Joecool85]

AFAIK, pin 2 should be 0 volts.

[bloodmist]

anyone else can help? do the voltages on the IC look ok?
also when I measure everything does the position of the pots change anything?
also how can I chech weather the transistor is fine? what are the voltages?
also how are capasitors checked?

[fixr1984]

i am measuring the voltages right now for you, just give me a few minutes

[fixr1984]

All your voltages are close to what i have, some of mine are a little bit higher but my batt read a little bit more so thats no big deal.
I had a similar problem with mine as well as with the little gem. Try to bypass the volume pot. Disconnect the 2 wires from the volume pot and connect them together
and then try again. In my case i had a bad pot and never got around to putting one in so mine is always at full volume.

[bloodmist]

well, I just shorted the two wires(volume) and it got louder but the squealing didn't  stop.
the voltages you mean both for IC and the transistor?
how can I check capasitors?
will pictures of this tyhing help?
are you able to plug effects into your ruby?

[bloodmist]

no one?