Ruby amp farty distortion... help!

[ozzu2000]

Hi!
I've built the Ruby amp, but in some cases it sounds very bad!
When on clean setting it sound very good, but as the volume increases, at the point it start to break into distortion it starts to appear a fizzy/farty noise, then as the note decays that noise disapears again.

I've tried:
- with a normal 4ohm speaker and also with guitar 8ohm one, and the results are the same...
- the circuit in now on a vero board, but on the bread board it did the same.
- building the normal little gem circuit (the one without the j-fet), and the result is the same.
- I've also tried diferent 386 chips (one rated for 9v and the oter for 18v iirc)
- I'm running on 10v from batteries

Any ideas?
I'll try to post a video, but I don't think my phone mic can capture that noise over the guitar tone.

Thanks!! 

[ozzu2000]

Video:

Photos of it's guts:

[pinkjimiphoton]

sounds like a ruby to me. what's the problem?

it DOES sound like your bat may be a little weak...these things get weird when the voltage drops too low, the jfet gets very weird, and i've gotten everything from horrible fuzz to almost uncontrollable oscillation that *ALMOST*  follows what you play.

the ruby isn't all that clean; if it's right, it sounds kinda like a blackface fender imho, and yours sounds fine.  did you try a different speaker? try running it on a wall wart, too. huge difference.

good luck mate

[ozzu2000]

Pay attention at the peak of intensity of the note, where it starts to get into distortion... it sounds bat at that spot...
I'm running it with 8 AA bateries, so power isn't an issue.
I've tried with an 8ohm speaker from an orange amp, and the result is the same.

[deadastronaut]

if you want ''clean'' only...this is very clean, and simple.

http://www.aronnelson.com/gallery/main.php/v/chickpea/clean+amp2.gif.html

dont forget the cut between pin 1-8...(i forgot to put it on the diagram ok)

breadboard it and try it..



btw which schematic did you use?...

[pinkjimiphoton]

check your caps, sounds like one may leak a little dc.

but it sounds pretty much like every other one i've heard sounds like tho. that distortion is just what it sounds like.

[ozzu2000]

Could it have to do with the type of caps I used? I used Polyester Film (Polybox) caps, and the electrolytic are just regular ones.
For the output resistor I used a 1W resistor instead of 1/4W  like the others.

But as far as I know none of the above can have an impact on sound... or can it?

Thanks

[pinkjimiphoton]

that shouldn't matter i wouldn't think.

[Kesh]

I don't really know the ruby, but that's pretty much what I'd expect a circuit like that to sound like when overdriven.

[ozzu2000]

This is what I expected the ruby to sound like (and many other like this one):
http://www.youtube.com/watch?v=hv-EN4qlCgc

What I get is that overdriven sound like on the above video, but behind it I hear very clearly what seems to be something like cat scratching on the speaker it's very hard to record it without a proper mic though 

I Tried on a 8" guitar speaker and the result is the same.
If I remove the NPN buffer transistor, the result is the same 

[jogina111]

I fixed this problem before but  I dont really know what happened. I just changed the input  jack and farting stopped.

[deadastronaut]

the ruby doesn't use a NPN transistor,  it uses a jfet.  mpf102/j201..

[jogina111]

I also experienced the same problems when I built it on vero. I rebuilt it on a PCB and BAM! It sounds wonderful  lots of range. I could get everything from super clean to heavy dream theater sounds.When I added a booster in front, I could get some heavy metal sounds like early metallica sounds.  The ruby amp sounds great. I suggest you rebuild it using the  layout from generalguitargadgets.

[ozzu2000]

the ruby doesn't use a NPN transistor,  it uses a jfet.  mpf102/j201..

Yes J-fet, my bad, I'm using a mpf102

[timd]

sounds like a ruby to me. what's the problem?

it DOES sound like your bat may be a little weak...these things get weird when the voltage drops too low, the jfet gets very weird, and i've gotten everything from horrible fuzz to almost uncontrollable oscillation that *ALMOST*  follows what you play.

the ruby isn't all that clean; if it's right, it sounds kinda like a blackface fender imho, and yours sounds fine.  did you try a different speaker? try running it on a wall wart, too. huge difference.

good luck mate

Yeah, I'm not sure I hear an issue either....and I think it sounds really good - like a great blues overdrive. I love the blackface comp.

[Kesh]

This is what I expected the ruby to sound like (and many other like this one):
http://www.youtube.com/watch?v=hv-EN4qlCgc

That's through a quite nice epeaker.

[ozzu2000]

Thats what I thought at first, but I tried with an orange speaker and the result was the same 

[chptunes]

Thats what I thought at first, but I tried with an orange speaker and the result was the same 

Look at the 1w Punch Amp:  http://www.diystompboxes.com/smfforum/index.php?topic=99271.0