Muff Fuzz built but load humming (Now with LINKS!)

[bass_econo]

I built the Muff Fuzz from this layout -
http://aronnelson.com/gallery/album17/EH_MUFF_FUZZ_VERO

When it is connected I get a loud humming.  Even when the battery is out and just connected (it is wired direct without a switch).  It does fuzz and it sounds good but the hum is almost as loud as the effect itself.  I've checked and recheck the components and wiring.  I disconnected the grounds from the input and output and it is still humming.  Any help would be appreciated.  I'm using a JRC 4558DD.

[jxoco]

just checking, you cut the copper traces everywhere there is a 'red square with a red dot' on the picture, right.

[bass_econo]

Yes!  here are some pics of the board.
http://img80.imageshack.us/img80/8884/front2jr.jpg
All of the pins on the chip are through it just looks that way on the pic.

http://img62.imageshack.us/img62/7596/back3yz.jpg

[jxoco]

very small picts, hard to see.
where are to two diodes? D1 and D2?
I can't see them in the picture...

[jxoco]

the two 680k resistors form a voltage divider with the center being connected to pins 3 and 5.
this is the first time I have seen the 10uf capacitor connected acoss the battery and not connected from the middle of the voltage divider (pins 3 and 5) to the ground.

The other fuzz at;
http://aronnelson.com/gallery/album17/EH_MUFF_FUZZ

correctly, to my thinking connects the 10uf from the center (pins 3 and 5 ) to the +9v ( of course the polarity of the capacitor has to be observed correctly.)

[bass_econo]

I built it without the diodes.  I read in a recent post that without the diodes it was a nice fuzz... which it is but with hum!!!   

Also look up I have replaced the pics with direct links instead.

[jxoco]

without the diodes its a very high gain amplifier.
maybe because the gain is so high and it's not in an enclosure, there is hum.
It's not sitting on top of your amp is it, picking up the hum from the power supply of the amp...

I don't know if I can diagnose much more, there is a limit to what I know.

I'd still consider putting the 10uf at the same connecting points as R3, the negative where it is now but the positive of the 10uf to the same end of R3 that is connected to pin 3 of the IC.

keep on trying things..

[bass_econo]

Thanks jxoco, for spending your time on this.  No it's not on the amp.  I'll go down and move that cap now. 

[WGTP]

If your not using diodes in the second op amp, are you using a resistor?  If not, your running the op amp in an open loop mode that provides too much gain.  If you don't use the diodes, add a 470k resistor in there for more reasonable gain.  The reference you saw may have been in reference to the Rockman, which is similiar.  It has the 470k resistor and can be used without the diodes.  Check out the recent Rockman/Muff Fuzz posts.  One of the down sides of this type design, is the large resistors make noise, but it shouldn't be that bad.   

[bass_econo]

OK I'm giving up on this one.  I tried the 470k resistor... I tried the diodes... nothing same loud hum.  I think it is something else.  I think I'm being dumb about something.  I disconnected the battery and I get the same loud hum.  It's the same hum like when your amp is on and you try to plug into the guitar.

I guess I'll try something else and look at this later.

[jxoco]

I just re-read your original post,
you should have the grounds of the input and output jacks connected together and connected to the Ground point on the circuit board, the 9v battery - connection.

[bass_econo]

I just re-read your original post,
you should have the grounds of the input and output jacks connected together and connected to the Ground point on the circuit board, the 9v battery - connection.

Naw it was connected as you said, I  was just rambling about things I was trying.  I'm going to start over with the other layout since I'm thinking you are right about the cap placement.

[tiges_ tendres]

http://www.harpamps.com/schematics/mufffuzz.pdf

this is the schematic I went from, I built it on regualr perf though.  The layout looks good, but I've never done strip board before, so I dont know if it's verified.

[jxoco]

R6 from your picture looks like brown black brown which is 100 ohms
it is supposed to be 100K which is brown black yellow

[bass_econo]

Yeah good catch but it is still not working.  I'm just going to call a "do-over" on this one and try it again this weekend. 

Thanks for all your help!