Benefits of having multiple Op amps?

Started by twoheadedfetus, January 28, 2018, 11:45:01 AM

Previous topic - Next topic

twoheadedfetus

I took apart an old computer speaker and found a jrc4558D inside, I wanted to build a simple distortion pedal and thought itd be cool to use it.
So far Ive only built a simple one op amp guitar amp using an lm386, and I really liked it actually, so im still almost a complete beginner.
Ive found out that the 4558 I have is a dual op amp, so id like to use both somehow if im gonna use it. What are some cool things I can do with two op amps that I cant with one? My original idea was just one op amp for gain and some hard clipping after it. What could I do with the second op amp?

I posted this in the beginner project section initially but it seems like its much more active here.

GibsonGM

Among many possibilities, you could:

use 1 section as an input buffer, the 2nd as clipper (gain stage)

use the 1st for clipping, put in some tone controls, use 2nd as a recovery stage.

You could soft clip w/diodes in the feedback loop in the 1st stage, then hard clip with the 2nd....even select between the 2 functions.

You could make the 1st into something like a Distortion +,   and use the 2nd as a switchable boost for solos....
  • SUPPORTER
MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

R O Tiree

...or you could build yourself a TS-808 clone and tweak it to taste.  That circuit is an ideal "beginner's project".
...you fritter and waste the hours in an off-hand way...

Mark Hammer


iainpunk

Quote from: twoheadedfetus on January 28, 2018, 11:45:01 AM
So far Ive only built a simple one op amp guitar amp using an lm386, and I really liked it actually, so im still almost a complete beginner.

May sound nitpicky, but the 386 is not really an opamp, but more a power amp.

However, i believe the original ts808 features a jrc4558 chip, so that would be a cool build!

Further more, you could build a 'precision rectifier circuit' to get a weird octave up-ish sound that would approximate a green ringer.
https://forum.allaboutcircuits.com/threads/good-full-wave-precision-rectifier.64943/

You could build a 3 band eq pedal. http://www.electroschematics.com/6201/3-band-equalizer/

Or you could build a high gain fuzz with active tone control. Etc....
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

thermionix

2HF, is the 4558 you found in the computer speaker socketed or soldered in?  I'm all for re-using things, but a brand new 4558 is about 40 cents, and desoldering one without damage can be a bit of a challenge.  Not trying to be a wet blanket, just pragmatic.

twoheadedfetus

Thanks for the suggestions everyone, I also thought about using one for gain with hard clipping after and then use the second as a variable treble boost

Quote from: thermionix on January 29, 2018, 06:59:38 PM
2HF, is the 4558 you found in the computer speaker socketed or soldered in?  I'm all for re-using things, but a brand new 4558 is about 40 cents, and desoldering one without damage can be a bit of a challenge.  Not trying to be a wet blanket, just pragmatic.

Its soldered in, this occured to me too, but ill try