second set of eyes please? lm324 quad opamp bmp

[pinkjimiphoton]

so i had an lm324 kicking around...and this behringer vd 1 bmp copy, and i got to thinking.

so i hit google, surfed around some and found this:



so i said, what the heck...and broke out diy layout creator, and came up with this:



does it look ok? do ya think it will fly? i checked the data sheet for the lm324 vs a 4558, and all the stuff seems to be ok (other than switching the last two opamp's order)

i think i can make it a little smaller, this is kinda the first draft, would really appreciate it if someone other than me could take a peek and see if i missed anything.

the big question i have is on tonman's schematic, it says VB, i'm assuming all of those points tie together...but the question is do i connect ic 2a pin 1 (pin 14 on my layout) to b+ as well? or am i missing something?

the lm324 pinout is like this
1 1 out
2 1 in -
3 1 in +
4 vcc
5 2 in +
6 2 in -
7 2 out

8 3 out
9 3 in -
10 3 out
11 ground
12 4 in +
13 4 in -
14 4 out

thanks as always in advance!!

[Quackzed]

vb is a second voltage, with r15 and 16 both 220k(as a voltage divider) its 1/2 b+ or 4.5v if b+ is +9v. so vb is 4.5v ic 2a is basically a buffer for the 4.5v so anywhere on the schematic that says O--vb goes to this point. you would not connect this to b+ as b+ is 9v.. is that your question?

[pinkjimiphoton]

yes!!! thanks!!

i take it the rest looks ok?

gonna see about whippin' this up maybe tomorrow, see what it does..

thanks again!

[linny1982]

Hey Jimi check your diodes. there are to many connections goin on there

[amptramp]

Check your LM324 pinout list for pin 10.  I don't believe it's an output.  It should be 3 in +.

[pinkjimiphoton]

thanks guys...i see a couple probs now thanks to you...

i'll revisit the diodes..dumb newb there!!lol

the pinout on the lm324, pin 10 is opamp 3 in +, 9 is 3 in  -, 8 is 3 out.

b- goes to 11, according to the diagram on the back of the package, anyways.

i'll revisit this today and see if i can get it right. thanks again gents!!

[pinkjimiphoton]

ok, i revamped it some...yes, there's a bit of extra room, but i figure if i have to play with stuff later (stuff to trim the circuit or boost gain/sustain etc) better to have a couple extra holes...besides, i have great big fat fumbly fingers to go with my great big fat fumbly brain...

moved the diode clipper, had to add a couple jumpers and move a couple things around, but 99% sure i got it right this time.

[pinkjimiphoton]

ok, i checked again and again, tried to make it a little smaller,, i BELIEVE its right, will probably start to build it tonite to see if it's good or not...



if anyone is bored enough to try it, please give me a yell if it works!!

BOM

C1: 100nF
C2: 10nF
C3: 4.7nF
C4: 10uF
C5: 470nF
C6: 150pF
C7: 470nF
C8: 220nF
C9: 10nF
C10: 100uF
C11: 100nF

D1: 1N914
D2: 1N914
D3: 1N914
D4: 1N914
D5: 1N914
D6: 1N914

IC1: QUAD OPAMP (LM324/TL074 ETC )

R1: 1M
R2: 47K
R3: 330K
R4: 10K
R5: 47K
R6: 330K
R7: 33K
R8: 1K
R9: 5.5K
R10: 330K
R11: 10K
R12: 10K
R13: 220K
R14: 100R
R15: 220K
R16: 220K
R17: 3.3K

SUSTAIN: 100K
TONE: 50K
VOLUME: 100K

[sundgist]

C2 and the jumper above should go to pins 4 and 5 on the opamp. They're fine in the previous layouts.

That's all I noticed at a glance.

[pinkjimiphoton]

good eyes...but...c2 should go from pin 5 to ground, and the jumper above it should go to pin 4...close!! thanks bro!!

here it's fixed...thanks!!!

[Quackzed]

sudoku...?
pffft!!!!
VERO!

[pinkjimiphoton]

today, i build!!! thanks for catching my mistake bro, i hope this thing rocks!!!

[nexekho]

today, i build!!! thanks for catching my mistake bro, i hope this thing rocks!!!

I just hope C10 can stretch that far... 

[pinkjimiphoton]

that's the beauty...i have some axials that will work perfectly.


EDIT: orrrrrrrrrrrrrrrrrrrrrrrrr

have c10 hit ground at  h 13

~saith the grasshoppah

[sundgist]

I've always wondered how the opamp muffs sound compared to the transistor versions.
Keep meaning to build one, but as i've already got a tranny muff, other projects keep jumping the queue.

[pinkjimiphoton]

me too...i'll know soon, almost done populating

[pinkjimiphoton]

well, i blew it...i couldn't get it to work...screwed something up.
but mictester on the other forum picked it up, and worked it up...a really really nice sounding fuzz!!!

the only thing is the bottom tone connection needs to move up one row.

really phat, super sustainy, all the good things ya want in a big muff!!

so...thanks to mictester, tonmann and eh, and all the other folks who kept spotting my mistakes.

i MAY have got it right...discovered the shell i was using to test it had a bad jack.

but i said screw it, and built this...it works great.