integrated circuit based fuzz circuits

[petey twofinger]

Hey there DIY guys , i seem to notice most fuzz circuits are transistor based . then i remembered mictesters ic ( very nice imho ) version of the burns buzzaround , then today i found myself watching the frantone peach fuzz demo and looking at the schematic / vero layout  . so  ic based fuzz isnt exactly super rare but i would say it isnt common although i am sure there must be others , i am not exactly gear guru guy here . but yeah why is this , why arent there more ic based fuzz circuits , if there are , which ones in fact utilize integrated circuits over transistors or do hybrid ( ic AND transistor based fuzz circuits as in the mictester bbb ) . immediately cost springs to the forefront , of course .

also , it seems to me part of the"fun" with fuzz is having to find the "right" or magic transistor(s)

for ME , personally , i have a painful back injury , i really like to limit tinker time and just build as quickly as possible as every minute i work represents an uncomfortable amount of recovery and the build process is not necessarily enjoyable as well .

i would think tolerances in integrated circuits would be extremely low if not non existent , like in a fuzz circuit , the transistor would have to be just right but all ic's are infact "just right" so that could lead to each unit sounding very similar / consistancy . wait , i just remembered , the ic big muff and corgan , and the prices going thru the roof ha haa .

today i found this :

http://www.eleccircuit.com/fuzz-audio-converter-using-lm324/

http://www.eleccircuit.com/simple-guitar-fuzz-effect-circuit-using-ic-741/

http://www.eleccircuit.com/wp-content/uploads/2014/07/the-schematic-of-this-project.jpg

http://www.eleccircuit.com/wp-content/uploads/2009/10/fuzz-audio-converter-using-lm324.jpg


has anyone here built these or anything like them , any thoughts ? is there an upside / downside to these designs ? i am guessing the reason is that ic is overkill , but still i am intrigued as it would be different and perhaps open up possibility's perhaps .

which would bring me to the main question , what is the readily available ( tayda ) substitution for the lm741 ic chip ? or better yet how about nixing the 741 and using a tl072 74 etc . burr brown cork sniffer fuzz !!

oh well . hey do they have germanium integrated CIRCUITS ? thats the real question there ...

[petey twofinger]

this text was taken from the description of the more complicated of the two circuits , the fuzz audio converter using lm324 :

" This is Fuzz audio converter circuit. By use diode 2 pcs. in feedback circuit of OP-AMP IC , number LM324. I make for build way music sound that have unusual character. By limit output voltage , give a hand net between 0.7Vp-p waves square signal that is the result that is will proportionate big compose harmonic be the odd number , resemble the sound of a donkey. The Resistor at use fine the depth of fuzz audio. It will use fine the level that want to is born top waves slitting goes up. And the resistor at use fine the intensity of output signal. The detail is other , see in circuit picture. "

i found his youtbe channel and pmed him about the donkey , awaiting response . who can i paypall to do a vero layout of this , so i can hear the Donkey ?

if you delve a litle further , you will be rewarded . there is indeed a treat in this tunnel .

[Keppy]

I designed an IC-based octave fuzz around a 4558.

Different opamps can sound vastly different in a fuzz, especially if you are clipping the opamp itself rather than using diode clipping. I developed my design with the 4558, then tried everything else I had once the design was done. Whaddaya know, the chip I designed it around sounded the best in that circuit. Being surprised by that made me feel pretty dumb. I think the 4558 is a descendant of the 741. Just try whatever opamps you have, then tweak to taste.

ICs aren't more expensive if they replace germanium transistors. Also, they have enough gain that you might only need one stage. They tend to be used less because they clip pretty hard most of the time. BJTs can clip pretty hard too, though, and people use those all the time. You either tweak the circuit to make them less harsh, or you use the harshness to your advantage.

I tend to use ICs in my dirt boxes because they're predictable and the designs tend to have fewer stages. That means if I want to change something I know exactly where to go, unlike having several boost/clip stages with varying degrees of filtering. I haven't had a lot of success with cascaded transistor designs, because when my first idea doesn't work I just go back to opamps.

http://www.eleccircuit.com/fuzz-audio-converter-using-lm324/

This design looks like the opamp inputs are switched. It looks like it's supposed to be a standard inverting gain stage with feedback clipping. The max gain with the inputs switched is only 11, though, so maybe I'm wrong.

http://www.eleccircuit.com/simple-guitar-fuzz-effect-circuit-using-ic-741/

This is a feedback clipper similar to a Tube Screamer. It won't sound much like a TS, though, because of the lack of filtering in the design. Max gain is about 100.

[petey twofinger]

very informative Keppy , thank you very much !

did you miss the part about the donkey ?

i popped over to tayda and typed in lm741 , tl071 came up so , yeah ... i was thinking maybe that pinout was odd , those are really old ic's i think . arent they the first op amp ever ? or am i confused again . did widlar do that one ? he was into donkeys . i seem to remember him bringing a live donkey to his place of employment , when they fired the landscaping service .

[pinkjimiphoton]

hey petey, great to lummox in here and find ya posting...
i've done a few ic fuzzes... look for my flying spaghetti monster. it's an ic fuzz with a ge fuzz in the feedback loop (switchable) so you can get some seriously outrageous fuzz sounds. if'n ya needs a schem or something, let me know i'll email it to ya.
ic's make great fuzzes. chris/mictester worked up my idea for a quad oa bmp a couple years ago that works great too, very much in the fuzz school but very different from a "usual" big muff.

[Buildtestrepeat]

When I started building pedals a few months ago for my own amusement I remembered I had an old electronics project from ..... when I was much younger.  It had a couple of LM741 chips in it which were probably manufactured around 1981/2.  One I put into a Jazz Fuzz clone which sounds cool and has a good range of noises.  The other ended up in a DOD 250 'grey' clone.  I've posted a pic of the Fuzz below complete with a prehistoric looking capacitor out of the same project.  The capacitor is way too large but I couldn't help myself.

[Gus]

The IC based muff fuzzes
RAT
Ultra fuzz

I posted IC fuzz schematics. 

You need to get the high pass and low pass filtering "right"

With the 741 read about gain bandwidth of an opamp
note the open loop bandwidth as the circuit gain is increased
think about what is changing

[anotherjim]

The LM324 circuit looks like a Schmitt trigger to me - a "Squarer" that is, so it isn't going to be adding harmonics to the original tone like many distortion systems do, it changes the waveform completely.
3 op-amps in the LM324 are unused. Should be able to use an LM348 dual amp instead if you wish. It contains the same op-amp type as the 324.

[FuzzFanatic71]

The Mid-Fi Demo Tape Fuzz is an awesome IC based fuzz. Uses an TL072 IC and a low part count. Well worth building as it goes from boost all the way up to fuzz and the EQ section is very useful. Sounds great on guitar and bass. I recently built 2 on PCBs given to me by a friend, but I'm sure I've seen vero and stripboard layouts floating about on the Internet.

[bool]

I honestly believe you meant a LM358?

[FuzzFanatic71]

If its me you are talking to then no. I built both of mine with TL072 and they sound how they are supposed to sound.

[bool]

Not you. That was re: "LM 348", obviously.

[FuzzFanatic71]

Not you. That was re: "LM 348", obviously.

My apologies, as it was just after my post and I'm a noob to electronics so I'm not schooled in all the different ICs and what they do. So it wasn't that obvious to me.

[pinkjimiphoton]

the venerable fender fuzz wah also is a chip based fuzz, and one of the thickest, chewiest mofo's i've yet encountered in a commercial pedal.

[monksanto]

The Mid-Fi Demo Tape Fuzz is an awesome IC based fuzz. Uses an TL072 IC and a low part count. Well worth building as it goes from boost all the way up to fuzz and the EQ section is very useful. Sounds great on guitar and bass. I recently built 2 on PCBs given to me by a friend, but I'm sure I've seen vero and stripboard layouts floating about on the Internet.

Yep awesome fuzz/tortion pedal, I'm about to make one myself. It really seems to live up to its name - ie cranked-to-buggery cassette-tape overdrive, nice & smooth, no "digital" crackle!

...Maybe it only means something to folk who have used their 4-tracks or their hi-fi's as a DI'd fuzz pedal in the past heh.... 

[anotherjim]

I honestly believe you meant a LM358?

Ooops! Yep, LM 358

[duck_arse]

I've posted a pic of the Fuzz below complete with a prehistoric looking capacitor out of the same project.  The capacitor is way too large but I couldn't help myself.

you mean that light blue electro?


petey - don't forget the angry beard, and this, with a germanium, 741, a normal switch, it's all there:

http://www.diystompboxes.com/smfforum/index.php?topic=577.0

[ashcat_lt]

As I understand it, the difference between distortion and fuzz is how much treble  you feed into.  Plug into a cranked up Rat with your guitar's T knob turned all the way down, and it's a pretty badass fuzz tone.  Take any distortion circuit and stick a fairly severe LPF on the front, and...

The LM324 will run off of a 3V rail.  Its output can swing all the way to 0V, but can only get to about a diode drop from the top rail.  If you run it off of 3V, and bias it to 1.5V, you get something very close to the asymmetrical clipping you'd get from a diode-to-ground clipper with an LED one way and a silicon diode the other.  It apparently also has some crossover distortion, which just adds to the fun.  I had a pretty badass "stoner metal" thing happening by cascading stages of these with some severe LPFing in and around them.

[petey twofinger]

thank you all for the replys , all of these circuits i have looked at them , the schemos and layouts , over the years but actually remembering what uses an ic vs transistors is another issue . jimmy , your spagetti circuit is a bit massive for what i had hoped to slap together . presently , on this idea i am looking for like 20 parts count or less type ideas , around there . i know its a cop out but , i have a few reasons for choosing that path on this .

the demo tape fuzz , i never really recorded like that much , maybe only once , with a walkman cassette that recorded , using an 1/8th adapter and a radio shack mixer with a boom box . i have never really forgiven myself , but then i see folks who love that circuit . embarrassingly enough i went on ebay and got 20 lm741 chips for 3 dollars , but my initial search showed them going for quite a bit more so i had panicked and assumed they were on the endangered high price list .

my plan is to build a few veros , starting with the esr graphic layout that someone was kind enough to share . then i should breadboard and monkey to come up with something of my own . the layout for the esr grphic mentions bending pins 1 5 and 8 on the ic socket to avoid cut outs at those locations . well the single lm741 ic chip i have here , it has those pins pre bent . it is also a circa 1978 cn chip i got out of an arcade machine . i have another on of those in my 250 but i digress .

so i am going to be collecting schemos and layouts for everything mentioned here for my ic fuzz folder , and you know i think i have the lm358 here but not sure about the 324  , as i bought some in quantity , i think , ha haa . paul in the lab devils triangle uses those chips , both of those circuits are really cool . try the osc ( not the seq ) thru a sub with a longish delay . i am still really curious about that donkey though , do you think he means oscillation maybe  ?

[PRR]

> thinking maybe that pinout was odd , those are really old ic's i think . arent they the first op amp ever ? or am i confused again . did widlar do that one ?

Not by a long shot. Op-Amps were used in WWII gun-control computers. There's a long series of tube op-amps, then a long run of transistor modules. Then IC op-amps of mediocre performance. Widlar did the '702 which was fairly cool. The blow-out (blow-up?) IC op-amp was Widlar's '709. Many millions used. Widlar asked Fairchild's Sporck for a raise, didn't get it, jumped to National Semiconductor. At NatSemi Widlar did the '101/'301 which gave better performance. Back at Fairchild they did the '741, THE OP-AMP which changed the world, very similar to the '301 but with internal compensation cap.

All the one-opamp in DIP-8 have the same five main points on the pin-out. (The other 3 pins, offset and compensation, vary between different parts.) Likewise all dual-opamps have the same pinout. You'd think this would be a pattern; no, there's two pinouts for quad-opamps.

> i seem to remember him bringing a live donkey to his place of employment , when they fired the landscaping service .

Sheep. Hauled in his Mercedes.
http://analogfootsteps.blogspot.com/2013/11/bob-widlar-and-sheep-at-national.html