need help again for debbuging my gristleizer...

[flapi]

Hi everybody !

I've bought two gristleizers pcb from <taylor, and i've built them this afternoon. Well, once they are finished, i tested them, and... nothing happens. Really. I've checked all my connections, wires... But it doesn't seem to be bad.
One thing makes me weird : the led is still on, and doesn't light on and off as the lfo should be.

I've used a max 1044 CPA+ from maxim integrated products, a TLO74CN from texas instruments, and a TLO72CP...

When i plug something in, i can hear it mostly distorted, but only the volume pot seem to be effective, the three others don't do anything.

Could someone help me Thanks !

( i've already built a gristleizer from samshing guitars, and it works now, after a fastidious debugging, but here, i really don't understand what happens...)

[Skruffyhound]

Follow the debugging thread at the top of the page. Otherwise there's no way to help you. Pictures also help.

[flapi]

yes, i've read the debugging thread... But there, i really don't understand what happens. It's a pcb professionnally built, i've built it properly ( i mean that i soldered each component at a time, and checked each value before...). The only thing that i don't really know are ics, if they can fit in this design or not.
I'll share pictures this night, when i'll get a camera.
thanks

[Skruffyhound]

If you include voltages from IC pins we can see a lot. You may have simply put an IC in backwards or mixed up a transistor pinout, but without voltages we are blind. I have a working Gristeizer built with Taylors layout, so if we have established that the PCB is good (I'm not the only one who had success) it means you have made a mistake. We all do it.
I can't guess what went wrong without voltages or other detailed info.
99% of all non-working effects are human error. Some of the most experienced people here will admit to having had a non- working build that they couldn't figure out until they noticed that they'd forgotten to place the IC's in the sockets.
Good luck

[flapi]

ok, thanks.

i'll go back tomorrow to my workshop, i'll take voltages from each ic... Well, maybe this night will give me some luck.

[flapi]

here are some pics, at first.

i used 10K 1/8 watt instead of normal 1/4 watt res'.... The wire on the left, which is soldered in the first hole of the volume pot goes to the negative tip of my jacks. I didn't know where to solder it... And don't worry : the out's wire jack is desoldered, but was here when i checked it... héhé. Tomorrow i'll give you voltages indications, but maybe this will help you.

[thedefog]

I had an issue with the switch wiring at first on mine. I'd triple check that. From looking at the picture, it looks like all your components are oriented correctly (ICs, Caps, Transistors). Time to break out the meter and get some voltages for us.

[Skruffyhound]

Ground is right between the rotary switch board connections and 9V - "G"

[flapi]

Ground is right between the rotary switch board connections and 9V - "G"

Yope, i know, but it was already used by my batterie clip... so i decided to take another one.

I built all the gristleizer after buying taylors recommanded parts, except for 10k res, i used 1/8 watt ones.
If someone can find something, i have to tell you that's the first time i have to do this, i'm kind of newb.. But at first, i think there's a problem with my MAX1044, voltages seems to be not so good...

Well, here are voltages i've just taken :

on battery clip : 9,09v
on battery pad on the board : 9,09v

IC1 : MAX1044   ( mouser : 700-MAX1044CPA )           
p1: 9,09
p2: 6,90
p3: 0,00
p4: 1,38
p5: 0,65
p6: 5,80
p7: 7,66
p8: 9,09

IC2 : TLO74CN ( mouser : 595-TL074CN )
p1: 0,68
p2: 0,06
p3: 0,00
p4: 9,09
p5: 0,00
p6: 8,15
p7: 8,15
p8: 8,23
p9: 0,68
p10: 0,00
p11: 0,65
p12: 0,00
p13: 0,00
p14: 0,69

IC3: TL072CP ( mouser :    595-TL072CP )
p1: 8,17
p2: 0,71
p3: 0,50
p4: 0,65
p5: 0,00
p6: 0,03
p7: 8,26
p8: 9,09

Q1 : 2N3906 ( mouser : 610-2N3906)
C: 4,21
B: 3,57
E: 4,20

Q2: 2N3904 ( mouser : 610-2N3904)
E: 0,00
B: 0,63
C: 1,84

Q3: 2N3819 ( mouser : 512-2N3819 )
D: 0,05
G: 0,61
S: 0,00

Diode Zener :
D1
A: 0,61
K: 1,04

D2
A: 0,69
K: 0,15

thanks again for any help !

[Hides-His-Eyes]

I'm sure you can see for yourself there's a power issue there somewhere. Is the 1044 there to provide bipolar power or 18V? Because you have neither.

[flapi]

the max1044 should provides bipolar supply, +9v and -9V... And here, on pin 5, where i should find -9v, i get O,65v !! But why it goes like that, i don't know... The capacitors are wired in the good way.. Should i be wrong, and ordered bad units ?

[thedefog]

the max1044 should provides bipolar supply, +9v and -9V... And here, on pin 5, where i should find -9v, i get O,65v !! But why it goes like that, i don't know... The capacitors are wired in the good way.. Should i be wrong, and ordered bad units ?

Check your soldering work for bridges in the power section and also recheck for cold solder joints. If you have another 1044, swap it out and see if it remedies it. The MAXX1044 is a somewhat delicate IC (at least I've destroyed one before), so I'd check the bridges/cold solder prior to swapping it in case you fried the first one from something like that.

[flapi]

ok, i've changed my max ic, and i've got now a -8,75V on pin 5, which is better. But the led doesn't flash on and off. Well, i think that i'm gonna change all my ics, and see what happens.
Thanks for the help, i'll let you know what happens !

[flapi]

So, i've build my second unit with the MAX1044 which works, and everything is fine. On the first one, nothing happens, i think that it has burnt all my ics and transistors... I have to buy a new MAX1044 and 2N3819.... Well.
Thanks for having helped me, i learned a lot this time.

-> Do you know if some other parts can be used instead of 2N3906 and 2N3819 ??

Sorry for having bored you with my mess...

cordially.

[Taylor]

2n3906 is a generic PNP. It's part of the shape control, and I don't think it's critical, so whatever general purpose PNP is common in your part of the world should work fine.

For the JFET, I think I have at least one suggestion  for a substitute in the PDF. I believe I used a J113 but please check the document to make sure. This part is more critical since it's being used as a voltage controlled resistor.

For your one that didn't work, there was definitely a problem around the 1044.