Red Llama = mo' problems

[glimmertwin]

Okay, now I gotta take my quandary to you guys...  I have searched the archives, traced, retraced, switched breadboards(twice), read the various debugging pages, and traced & retraced again.  It's a simple circuit so I wouldn't think that I would have this many problems.  In short I have been trying to build a Red Llama on a breadboard but it jut hasn't worked out for me.  The most I get out of it is some sort of weird fizzy gated sound when I hit the strings extra hard. 

I went on ahead and grounded all unused pins, and it worked for about 10 seconds and then the volume started decreasing and it went back to faint, buzzy and gated sounding.  At this point I'm kind of at a loss for what to do.  Given the relative simplicity of this circuit, I am assuming I have a bad part somewhere in there(maybe the 4049UBE?) but I don't know enough to know if that is a common problem with chips like this.  In all honesty, I didn't take static precautions before I handled the chip(maybe that was my 'boo boo')...

After giving a try using Dragon's vero board layout, I took it apart and rebuilt it using MartyB's, and after that didn't work I took it apart and tried to build it straight from Steve Cerruti's schematic(all came from the layout library on this site).  Everytime I get the same problem.  The only time I got an acceptable tone was right after I grounded all unused pins and THEN it worked for a few glorious seconds until it went back into "low gated sound" mode slowly.  It was almost as if someone turned a knob down slowly until it went back to the gated effect thing- really weird.  I just don't get it...  I used all the parts exactly per the schematic(no subs).  These breadboards may also be a problem because they are very old and a little dingy - I sometimes wonder if something inside of it is preventing accurate testing(but other prototyping has responded well on these boards).   

To be honest, I'm still relatively new at this so maybe some of you pro's can pick out a red flag out of my description.  I feel silly having to ask you guys for help considering how easy this circuit seems and the relative success of most who have tried this project.  So what do you guys suggest?  Would a voltage test of the IC pinout help in this case?  Am I retarded?

[glimmertwin]

Okay...so thinking out loud after tinkering with another project tonight that I haven't got to work quiet right(a PNP fuzz).....  I got a similar sound that was described earlier out of that project only there I had to do a little "as close as I could get it" substitutions on a few of the resistors.  From reading back through the archives, this appears to be caused by a biasing problem which is all well and good for the fuzz face, but for the red llama, how would I have a similar bias problem if the gain is coming from an IC and not some leaky old Ge transistor? 

Is that too much of an assumption to make that I might have a biasing problem on this project just because I had a pretty clear biasing problem on the other project?  I must have some sort of bad resistor, IC or capacitor or something(all though all the parts are brand new).  Hmmm...

...still troubleshooting on my own until you guys show me the error of my ways

[gez]

Didn't read through all your posts.  Hint: voltages speak louder than a thousand words! 

[gez]

Oh...and a link to a schematic! 

[Bernardduur]

I never grounded all anused pins, but put a current on the "begin" pins and left the "after" pins unconnected.

[A.S.P.]

same no-schem-problem

[Bernardduur]

Oh, I used this schematic for mine

[bluesdevil]

I can attest Dragonfly's layout definitely works. After all your various attempts, I would guess you have a wrong value resistor or capacitor or maybe the chip could be bad. Also, if you're using an IC socket (recommended!!), make sure all the pins are going in correctly and not being bent offsides or inward.
   Report your pin voltages along with battery voltage going into board and I'll compare it to mine.

[glimmertwin]

Thanks for the help guys.  I read the thread on the Tube Sound Fuzz project and I think it might have drifted a little over my head(still learning here). 

The schematic I used is here http://aronnelson.com/gallery/SteveC/llama2?full=1....but I had the same problem using Dragonfly's vero layout and MartyB's layout as well.   

Here are the voltages I was getting from a fresh(9.34v) battery. 
pin 1: 9.34
pin 2: 8.8
pin 3: 8.84
pin 4: 8.98
pin 5: 9.34
pin 6: 8.97
pin 7: 9.34
pin 8: 9.22
pin 9: 9.34
pin 10: 8.94
pin 11: 9.34
pin 12: 8.9
pin 13: 0
pin 14: 8.68
pin 15: 8.72
pin 16: 0

I assume something is wrong here because I should be getting 0v at pin 8 at least right?

....I do have an IC socket but this breadboard is slightly raised at the edges so it won't allow the socket to sit into the holes properly so I just used the IC directly to the breadboard.  All of the pins are evenly alligned and properly seated.  I have checked the resistor codes to make sure they match the values I ordered from Mouser and the capacitors seem to be correct as well....maybe I have a bad chip?

If you don't mind, the values of your known working chip would be very helpful.  Thanks!!!!

[bluesdevil]

Do you have the 1k resistor that goes between the battery power supply and the positive power rail in the circuit? I don't think you should have the full battery power hitting the IC like your voltages are reading on some of those pins. That's the first thing I noticed at a glance.
Here are my readings from a fresh battery (9.29v):

p1 - 5.27
p2 - 2.081
p3- 2.078
p4 - .001
p5-  5.27
p6 - .001
p7 - 5,27
p8 - 0
p9 - 5.27
p10 - .001
p11-5.27
p12 - .001
p13 - 0
p14- 2.079
15 - 2.081
p16 - 0

[bluesdevil]

I assume something is wrong here because I should be getting 0v at pin 8 at least right?

Definitely should be at o volts.... make sure nothing is shorting against that pin and that it's actually going to ground.

[A.S.P.]

if everything is wired correctly, but still doesn`t work, try "breadboardwiggling"...

move around/press the components a little, while measuring pin8 voltage directly at the chip-leg.

(I got 2 kinds of breadboards: expensive ones, where every circuit works  ,
and cheap ones, where even simple circuits won`t work, when the board has been used for a couple of times  .  Contact-quality can vary much!)

[gez]

Looks as though pin 8 is connected to V+ or something.  It should connect to ground.

[A.S.P.]

or not grounded properly, so everything gets pulled up...
hence the wirewiggle advise

[Paul Perry (Frostwave)]

or not grounded properly, so everything gets pulled up...
hence the wirewiggle advise

Yeah, pull the chip & see what the voltage is at pin 8 then. (an argument for using sockets in a breadboard!!)

[gaussmarkov]

dang, i actually made a graphic of my red llama breadboard layout when i made one.  but i can't post it because i am on the road and it's on a computer at home.  if you still haven't figured it out, i'll put it up for you glimmertwin when i get home in february.

one other thought:  the chip is supposed to be carefully protected from static charges.  anderton says they fry easily in his write up on the tube sound fuzz.  never had a 4049 go bad on me but i'm sure it happens.  so maybe ...

keep at it.  you are going to love this circuit.   

[glimmertwin]

Thanks for all the help guys.  Suspecting that the breadboard may have been acting funny, I soldered everything to perfboard instead....and of course it still didn't work.  I ended up calling my Dad over to look at the circuit - he is the one who actually has an electronics degree and gave me all the meters, oscilliscopes, bread boards, etc.  After measuring voltage & continuity all through the circuit, we still couldn't figure out what was going on short of there being some bad component(possibly the diode or the electrolytic from pin 7 to because no matter what I do, there is voltage on that 8th pin.  Anyway, I ordered another set of parts and I am going to give it a shot again.  I think my Dad could have figured it out normally, but he was kind of dingy from all the meds he was on after he had some weird allergic reaction earlier today...  Anyway I will update you guys what happens when I get the replacement parts. 

...down but not out...

[gaussmarkov]

... (an argument for using sockets in a breadboard!!)

hah!  cool observation.  thanks, paul!