superfuzz f'd up ;)

[pinkjimiphoton]

hi guys, built IvIark's layout here: http://tagboardeffects.blogspot.com/2012/01/univox-super-fuzz.html?showComment=1341962151195#c8682435058951239543

built this up, but i can't get a sound thru it.
don't know which schematic he used for it, but i did ask...
i'll try audio probing thru it tomorrow, but no dice as of yet...
used 5088's, checked the pinout and made sure was right to the vero layout..

voltages are on acid:

q1:
e 1.95
b 0
c o

q2
e 8.78
b 9.30
c 9.48

q3
e 1.95
b 2.57
c 2.03

q4
e 1.08
b 1.67
c 3.49

q5
e 1.08
b 1.67
c 3.50

q6
e 1.27
b 1.95
c 1.28

any ideas? gotta gig tonite (yay, on a tuesday!) so can't mess with it till tomorrow...

thanks

jimi

[LucifersTrip]

Though it's not your problem if you're getting no sound, my first suggestion is to use lower gain transistors (125-250 hfe...I asked on another forum and someone measured his originals, and they were in that range)

here are the voltages solidhex posted from his bandmate's killer sounding original:
http://www.diystompboxes.com/smfforum/index.php?topic=64068.0

C B E
Q1 6.01 .66 .117
Q2 8.88 6.01 5.41
Q3 6.23 3.27 2.72
Q4 3.1 1.7 1.11
Q5 3.1 1.67 1.11
Q6 5.75 .98 .361

you'll probably have to adjust resistors around Q6 to get Q6C to 5.75, if you like it that way...or use a really low gain one there. I was able hit 5.8v if I used a 55 hfe transistor in Q6

pm sent with my build report from the other forum...might help

[R.G.]

q1:
e 1.95
b 0
c o

NPN transistors can't possibly be amplifying audio well if their base and collector are at the same voltage. Something's wrong with this one. A guess might be something that either opens the power supply to the collector resistor and the base bias, or shorts them to ground.

q2
e 8.78
b 9.30
c 9.48

Is the emitter *really* up at nearly the power supply?? Did you get a schematic with this?

q3
e 1.95
b 2.57
c 2.03

Something bad wrong if the collector is lower than the base. This one is saturated hard. No audio goes through here.

q4
e 1.08
b 1.67
c 3.49

OK.

q5
e 1.08
b 1.67
c 3.50

OK

q6
e 1.27
b 1.95
c 1.28

Again, something bad wrong if the collector is lower than the base.

The original used 2SC828, which are ECB pinout. You used 2N5088, which are EBC. Did the layout assume ECB or EBC?

[pinkjimiphoton]

thanks RG and lu...

i used this layout...in the thread on mark's blog, someone had claimed to build it, so i figured i'd give it a shot.



i checked all the transistors with my meter, tried to get 'em all in the same range, in this case

all were roughly between 350 and 380hfe....which seems to be about twice as hot as the circuit as laid out needs.

i'm gonna remove 'em all, and socket. i don't like to socket things as they tend to not hold the leads very securely, and if the pedal needs to get shipped (in this case to a friend
in anchorage, half way across the planet) i don't want it to fall apart in transit.

shoot.

i wasn't sure which schematic IvIark used, so i looked around and found this one, which i believe he used:



i guess i'll start by swapping out the trannys for sockets, and try to find the proper gain ranges amongst the stuff i have on hand...

will check in later with the results.

gonna compare the schem and layout side by side.

the 5088's were set up, with flat side facing, ebc, and i installed them as specified.

wondering if, tho, i may have reversed them inadvertantly...gonna go work on it . i hope i didn't do that....again.   

thanks guys!

[pinkjimiphoton]

well, we have achieved super fuzz...but only the octave up part ...on one so far. in that case, stupid me had the output one rail too high, along with the two switch connections...moved each down one rail, and it's working. sounds a lot like gus's ousb! that's with the higher gained transistors.

the other one, i had q1 off by one rail. 
sheesh...

fixed that, and socketed it. still no dice. if i BEAT on it, i can get a little signal thru. interestingly, it works better with q1 in backwards...so somethings messed up...voltages are better, will write 'em down when i get back from going over them.

but some success to start is good. i am thinking the 5088 may be damaged, cuz i think it was used in another build, so i'm gonna swap it out.

more later...thanks guys

[bhill]

Jimi, I built one with 5089's and it is one screaming nasty fuzz. Dead quiet also, so I wouldn't worry about the 88's. I did mine on pcb, so I can't really say anything about Mark's vero, but the voltages on everything but the octave pair (q4 and 5) are definitely off. Missing jumper?

[pinkjimiphoton]

hey bro,
the one that's working is SCREAMING...A REALLY RUDE NASTY SUPER LOUD FUZZ!
iit's a little brighter than my shin-ei 8tr fuzz wah, but i think that one is germanium...i'll have to look!!

i did notice on the working one, the voltages are different, particularly on q1... i got it passing signal, so it's just a matter of finding the problem.
thanks for the heads up on the 89's, i won't worry about swapping the 88's out now.

back to work...too much time on the net, i'll never get anything done.

[digi2t]

Bro, first off, check your PM.

Segundo, I scored a bag of 200 Panasonic 2SC828-R's a while back. The "R" hfe range is 180 to 360, which is higher than the "Q" range (130-280), but lower than the 2N5088's. Tell me what gains you need for each tranny, and I'll go through them with the Peak Atlas. I'll find 6 that are close to your specs, and bring them down on Friday night, if it's a go.

Then you'll have some more authentic trannies in that bad boy!

Cheers,
Dino

[pinkjimiphoton]

awesome!
lu said his best results were about 235 for q1, 160 for q2-5, and 55 for q6 i think on the other forum.
i'll keep the 6 you bring for mine, use the 5088's in my friends. the one thing with the higher gains is it seems to be louder, but it's more fizzy treble and less warmth.
i'll send ya home with some mn3007's or something!
thanks bro!

[Gus]

I just did a sim of the first two transistors I simmed 2n2222s and 2n5089s not much change at all with the operating points.  Q1 C about 5.6 and Q2 E about  4.9VDC 2n5089s.
Q1 C and Q2 E about the same with the 2n2222s.

Don't get stuck with transistor numbers with this circuit.

[pinkjimiphoton]

thanks, gus... the 88 version i built doesn't sound all that much like my original shin-ei fuzz wah, but it may be because it doesn't have the wah circuit...it's much brighter.

but the octave up sounds alot like your ousb...it's good.

still gotta debug it a little, and get the other working...but so far, all good.

[LucifersTrip]

awesome!
lu said his best results were about 235 for q1, 160 for q2-5, and 55 for q6 i think on the other forum.

What I said was that is how I got almost dead on to solidhex's voltages from his bandmate's killer sounding original...
I did get better results with a higher Q1 than Q2 (I probed right after Q2 and compared boosts) and that the only way I could get 5.75v on Q6 collector without altering resistors was with a low gain Q6 (hfe 55).

Whether that's "best results" is up to you...

i'll keep the 6 you bring for mine, use the 5088's in my friends.  the one thing with the higher gains is it seems to be louder, but it's more fizzy treble and less warmth.

yes, similar to what I got...try adjusting the bias of that last transistor and you'll hear a difference. It's  just a recovery stage, but it does change the tone...