Building A Muffer clone as a first project, and am having a few problems

[markymayhem]

OK.. I just built the "muffer" from muzique.com..  http://www.muzique.com/schem/muff.gif
Simple 2 diode clipping and transistor boost.  It is my first effect, first circuit board, and the first time I laid out a circuit board from scratch.  I also couldn't find all of the EXACT parts..  I built it on one of those boards with a ton of un-connected holes with little copper rims on them.   It didn't work at all at first, and I traced it down to a missing connection between the 10uf cap off the diodes and the collector.  Finally!  Sound when not in bypass mode!  CRAPPY, cruddy compressed wierdly, quiet sound, but sound none the less.  My changes were to use tantalium non-polar caps for the 1uf caps, cuz I had them, and a random 2n4401 NPN transistor.  I also tried a random old germanium transistor I had..  It still sounds like crap...  I used a transistyor socket, but the caps are soldered in and if they are whats causing the problem, I may have to go back to the drawing board...

[burnt fingers]

 There is most likely a bad connection somewhere.  The 4401 transistor should work fine for this.  The random geranium probably wont.  The chances of you having a bad cap are slim.  The chances of ruining one of the diodes during soldering are pretty high if you put too much heat for too long, but I would recheck the connections, look for bad solder joints, get some readings with a multi meter. I think you need to visit the what to do when it doesn't work thread

I have a small perf layout for this as it was my second project ever and I loved the little bugger. 

http://aronnelson.com/gallery/Burnt-Fingers-stuff/Muffer_perf

I know you already build yours but you may be able to use this for reference as far as connections go.

Scott

[markymayhem]

Here's all parts of the debugging list not listed:

The transistor pinout is correct
It is low volume, distorts/compresseses... weirdly...  not much "fuzz" at all
brand new battery out of the package
I'll proble the voltages at each pin of the transistor socket, and at each end of each diode.. in a little while..  I have a peavey t-60 with a dead pickup to fix first.

[markymayhem]

I wasn't wondering about a 'bad' cap, but if I could sub the non-polar tanatalainum (or whatever it's called) for polarized electrolyitc caps.  Overheated diode is a possibility, because I put the pins to close together, and had some solder going where I didn't want it and heated those connections quite a few times.  I checked all the connections, but I can do it again..  should I measure the voltage at either side of each diode with the ground refrence clipped to ground?  What should it be?  I'll measure the voltages, check my second post in this thread

[markymayhem]

voltages:

both diodes (@ 20v) .24-.25 through the diode, and .05-.06 vs ground

0.00 at all parts of the transistor @ 20v, .02 @ collector @ 2v

[markymayhem]

OK, I went though and cleaned up the solder traces, checked all the connections.  It seems to work OK, except it is VERY quiet, not 'fuzz' and minimal gain.

[markymayhem]

Are the voltages I got correct? 

[burnt fingers]

Those voltages are off.  You should get 4.5 to 5 volts at the collector.  I measured mine and I have 5 volts at the collector and a little under 2 at the base.   

Scott

[markymayhem]

and that's with the battery in, switch on and no plugs plugged in?

[burnt fingers]

You should have something plugged into the input jack otherwise the battery will not be on. 

Scott

[markymayhem]

I'll try again here shortly

[markymayhem]

OK...  zero at the emitter, .2-.4 at the base, 9.5 at the collector...  these are wrong, but what does that mean?

[burnt fingers]

If you're getting full voltage at the collector you have a short somewhere that's bypassing the 10k reisistor between the 9v and the collector.  Check those connections carefully.  Look for little bits of solder,even tiny hair thin bits will cause a short.

Scott

[markymayhem]

no no short... while examining it under a glass, I noticed I used a 10k instead of the 100k, so I'm going to fix that..  I do measure a voltage drop of about .3 volts across either side of the proper 10k resistor..

[markymayhem]

OK.. fixed the wrong value resistor..  Now I get .02V at emitter,  .5V at base, 4.98V at collector...  At first, I pluged it in and got NO sound.  While probing around in there, my finger touched the connection from the eimitter to the 100k resistor and I picked up a southern-style gospel preacher from some AM radio station!  Went and checked all of my solder connections, and now I am at basically the same place.  It works.. sort of..  The weird compression is gone, now it's just very VERY quiet

[markymayhem]

any new ideas?   

[markymayhem]

I'm thinking it's because I used non-polar tantalaium caps for the input and output caps.  I don't have any 1uf polar eletolytic caps.. I do have 2 non-polar electrolytic caps though... any benefit to trying those?

[ildar]

Check those tantalums...every tantalum cap I've ever come across is polar...not that that is the gospel, but check them again. For a booster/distortion circuit, you can normally use a non-polar in place of a polar with no problem. AFAIK, the polar 1uf caps are often used because they're generally smaller than many film 1uf caps.
Anyhow, check those tants again, and check the orientation of the transistor.

[burnt fingers]

OK.. fixed the wrong value resistor..  Now I get .02V at emitter,  .5V at base, 4.98V at collector...  At first, I pluged it in and got NO sound.  While probing around in there, my finger touched the connection from the eimitter to the 100k resistor and I picked up a southern-style gospel preacher from some AM radio station!  Went and checked all of my solder connections, and now I am at basically the same place.  It works.. sort of..  The weird compression is gone, now it's just very VERY quiet

There is not a 100k connected to the emitter on this circuit.  You have a 10k connected to the collector, a 150 ohm connected to the emitter a 470k from collector to base and a 100k from base to ground.  Sounds like you have some wrong values or you may have some connections on the tranny mixed up


Scott

[markymayhem]

No.. I just wasn't to clear about what was where.
looking at it, I have 150 @ emitter to ground,  10k @ collector to 9v +, 100k from BASE to ground
those all look good..  it's the 470k that might be wrong.  it's connected to the + of the 10uf cap & collector &  at one end of the output cap (the end connected to the other resistor)  & to the base..