IF!!!... you were going to fu#k with the Op Amp Big Muff. gain re-distribution..

[Quackzed]

ok. there's ALOT of gain at the 741 stage (i'll supply a schematic... ) but YES! if you were going to re-distribute the crazy amount of gain!!! what/how would you do it?!? (keep the gain somewhat (ballpark) similar) how would  you re-distribute the gain of an 'OP AMP' BMP?!?!? ( noise? oscillaion? Happiness?!) ....
The OP AMP BMP is  a    BIT of   a   Square circle....    yes it's ... er...  ODD!!!!!
SO!!
IF you were to do a bmp  AS aN OP AMP?!? HOW would you distribute the gain to avoid... noise, oscillation, etc... i.e. (bad side effects) while maintaining the "important" BMP attributes?
==== i have an op amp BMP build that was NOISEY!!!! so i removed gain at the 741 and moved it to the first stage!? 60x to @ 10x 10x to @ 60x... RIGHT??? i know! rails...  but... what would YOU do?i

[Quackzed]

[Quackzed]

Don't give me B.S.! this is a Puzzle/Test! Why distribute Gain here VS> There. Explain yourself! the filter 'sallen key filter' in between? why not filter high high end early? why not share gain?!? why not 1 diode pair and a gain stage after? etc...  wtf? tell me why it is the way it is!
solve it. why do it YOUR way?
re: i did it MY way! frankpletive deleted... tell me i'm wrong! fix the op amp bmp!

[stonerbox]

You seem to be in a lot of pain.

[bool]

I would "sustainify" the very first stage: use clipping diodes, a small couple-hundred pF cap and a bigger R4 in IC1A nfb. The get the R13 down to where the noise starts to become less.

The lowpass appears to have gain in x10 range. Imo it would be sensible to get the "first stage into LPF" gain plus headroom right. Imo it would be sensible to use leds (perhaps greens) in the first stage AND recalculate the LPF to lower overall gain but equal/similar-enough filtering characteristic to not clip the first chip to rails ever - but to provide enough sustain and constant signal level to get the 741 stage to cook.

(Note: I didn't mess with the muff ever, but got to fix the gain distribution in other types of multi-stage dirtboxes, so take the above as "hypothetical only" advice).

HTH

[Quackzed]

  sorry if i was a bit obnoxious, i've just been messing with this thing for a few days and had to get heavy handed with it. bit of a re-design after alot of gentle nudging and frustration. so i just wanted to see if i was thinking straight without too much leading to 'my' solution...
worth the effort tho. things a sledgehammer of a fuzz!!!

bool: i agree with your suggestions. basically up the gain in the first stage ( respecting the limits to avoid rail clipping) to a good strong high headroom signal to allow lowering the gain of the 741 to avoid noisiness. getting the 'first stage into the lpf' part just right as you said i.e.: to get the biggest signal while maintaining the lpf frequencys (as well as maybee upping the lpf gain to do the same and do its share of amplifying without clipping)...
and keep old man 741 from throwing his back out...

t my thinking also that theres only so much you you can do without clipping or hitting the rails of the first op amp,  the lpf may as well clip with leds as its peaks are gonna be clipped off anyway (though it may matter when the signal decays 'out ' of cliiping at the 741- thought i think the 741 would still be clipping after the lpf stopped clipping )-- but yeah, share the load-- you still need the 741 to do some heavy lifting but it makes sense to me to share the amplifying work as much as possible to keep the 741 as noise free as possible... worked for me...

all i did was lower the gain of the 741 and get it back at the first stage... (enough to clip the 1st stage rails even)  but not so much that the rail clipping makes it past the 741 clipping... the 741 is still the heaviest clipper...  also a little high end pf taming early on...

[Plexi]

You seem to be in a lot of pain.

[emoji23]

[pinkjimiphoton]

gil,
i had worked up a pretty much fail'd quad oa bmp a few years back, and my bud chris (mictester) on "the forbidden forum" came up with a really nice sounding variant. if ya want i can see if i can find the layout for it, i don't think a schematic exists.

but to the best of my recollection, all the ic muffs kinda sucked arse. noisy, hissy, and like, shitty unusable distortion

[Quackzed]

yeah, you'd think op amps would take alot of the variability out of the equation (tranny gains bandwidth etc..) but i think its just asking too much from the last op amp stage... with more gain up front (@ 100x  ) and less at the end (from @60x to @10x) its just as gainy (really more gainy) and still has that nice soft big muff attack) without the fizzy 'ocean sound' on the note decay...

i even stuck some back to back 'in line' diodes between c7 and r10 for a crude 'noise gate', works well in that spot though you do lose a bit of  gain (theres plenty to spare)
i took it out but might make it switchable...

i think i'm gonna stick with this one for now , i've just spent too much time trying to bend it to my own cruel intentions to leave it. and now it seems the fizz has crept back in?!? !@#$ !!! hopefully thatll go away once i clean it up and box it... maybee a bad joint somewhere after removing resoldering replacing redacting recusing and regretting...

[bloxstompboxes]

Hey Quackzed, Glad to see you're enjoying working on the Op Amp Muff. Hope none of it is my fault. The ones I built seemed to do well. Not excessive on the noise but, yes there is a ton of gain. I built mine stock. Maybe try a different op amp than the 741.

[Plexi]

This thread and the idea of a sea of gain, made me reconsider to build the Fuzz War, and move the IC-BM to 1st place.

And now, in opposite to the OP's suffering; is there any way of get MORE gain? 

[Quackzed]

Hey Quackzed, Glad to see you're enjoying working on the Op Amp Muff.

I AM, and it went together like a breeze!!! really nice work! I think its just the 741's i had , they were from an ebay seller and were a bit noisy! But i'd never have been satisfied to just leave it alone anyway, it's just my nature!  and after a little fiddle it sounds great!!! thanks again!
i usually perf everything but it was a pleasure to not have to mess with any of that and just populate the board!

is there any way of get MORE gain?

oh yes! with 3 op amp stages you can tweak (tho the second 'sallen key filter' stage is probably best left alone) but yes, the first stage is a good candidate, though its a bit like pouring gasoline into a volcano... but r1 56k in the schem can be lowered , its got a gain of 6 as is (signal out is 6x bigger than signal in) if you made it 3k3 it'd be a gain of 100!!! but if you go THAT low, be sure to keep well inside the pentagram...