Busting the myth of magical op-amps and diodes...? 

Brian, the 4558 had pins 5 & 6 installed in the breadboard at an angle, thus affecting the linearity of the electron flow, altering the intra-lead phase coherence, and screwing up the harmonic convergence of the ultra-linear bifet dynamic perambulator that makes the 4558 magical. If you had put it in with the leads straight, it would have vacuumed the shag carpet on the noise floor and not only would it have sounded EXACTLY like a TS, it would have turned your guitar into a Strat and made you sound exactly like SRV. I call foul.

THIS is exactly the kind of NO BS demonstration we need in order to really discern and to really assess gear. Trust your ears and keep ever mindful of the "psycho" in psycho-acoustics. Placebo effects are FOR REAL, guys. Whatever the actual outcome, Brian Wampler cannot be given enough praise for introducing this down-to-earth method (inter-subjective comparison is the foundation of science) - which, obviously is beyond the means of many here, so the value is even greater. I'm sure, we all appreciate that there are differences - just let's concentrate on REAL differences and keep from hair splitting and cork sniffing. Thank you again, Brian, and keep up the good work! P.S. No reasonable person can disagree that anything purple just has to be SUPERIOR…

You have to love how honest and transparent Brian is when it comes to pedals.

(after the 4558) "here's the 4559. you *may* notice a little more gain." duh. it's one louder.

Not dull at all Brian, very imformative comparison! Ive always found the diode comparison tricky because of the volume differences but i agree with you, op-amp or diode differences are subtle ones. Cheers mate!

Let's do some direct comparisons! Dual op-amps (soft-clipping) 1:24 JRC 4580D 1:45 TLC 2262 2:06 OP 275 2:20 TL O62 3:04 LM 833 3:28 JRC 4558D 3:49 LM 358 4:33 4559 5:18 OPA 2604 5:44 AD 712 6:27 OPA 2134PA 7:03 JRC 2043DD Diodes (hard-clipping) 8:50 4148 9:48 / 9:55 1N192 10:51 BAT46 11:20 BAT41 11:57 blue LEDs 12:31 orange LEDs 12:49 pink LEDs 13:21 red LEDs 14:11 1N34A (Ge) 14:49 no diodes (op-amp clipping itself) 16:06 / 16:19 clean boost into same circuit

Excellent video. I might suggest to my wife that we watch it together tomorrow night, I'm sure she will share my enthusiasm!!

This is my favorite video in a long time. From anyone. Thanks for doing this. That was really fun.

Thanks Brian, Have enjoyed the Tumnus and the Sovereign very much from your bench, great work! Your willingness to share your knowledge is unusual and refreshing.

After viewing countless guitar, amp and pedal reviews and demonstrations on you tube, I can honestly say that this is the coolest video I've seen so far. Instant subscribe.

Thanks Brian. This was a great video. I've been learning for the last year or so and you've helped me a ton. This video will get marked for future reference. You rock man. Thank you!!

Omg, this is so enlightening! I'll watch anything like this multiple times - so fun to see an objective comparison of different components like this.

I absolutely enjoyed this Brian! I love to tinker with electronics. My Dad was an electronics tech (Radio and TV in those days) so I grew up in the late 1950's from day one smelling solder and watching tubes glow. Dad was also a guitar player and so I started playing the guitar at age 5. I played guitar professionally for 35+ years and had some schooling in electronics along the way. So again, I totally enjoyed this video. Now I want to tear open some of my pedals and experiment...lol! Now subbed!

I had some similar fun one day. Put an 8-pin socket in my TS-9 and an SD-1 and spent the day swapping opamps, everything from a Burr Brown to a TL072 from Radio Shack. Realized after a couple hours that, while differences were there, they were very subtle and nothing “magical” in any one. It was the overall design that made the difference.

Thanks Brian Im modding my rat2 watching this and I'm glad I found some different diode ideas for my 3-way dpdt. I love how you still help the gear nerd/ diy community. Thanks man. btw your pedals are beautiful inside and out.

Well done! Thank you, I enjoyed hearing this. I did expect to hear greater difference’s, but as you said it’s really the sum of all the parts , the variance and the design.

Very informative Brian! Your videos are never boring! I enjoy learning things from. You know what you're talking about! I don't have 7 of your pedals for nothing! You make great pedals!

Dull? Hell no. I didn't blink through your whole video. Gotta do more like this. Different types, chorus, tremolo, etc...Thanks Brian!

Man, I really loved this. Especially the part with the different color LEDs. I've replaced diodes with LEDs and been extremely happy with the results, but I just grabbed what was on hand at the time that I wasn't using for other stuff (mostly yellows). But now I wanna throw some blue ones in! I really hope you do some more "boring" videos like this one. This was incredibly cool, so thanks, man!

Loved this video man! I could watch these types of vids all day and there's little to none around. Idk how you'd do it but showing the massive change the filtering in the circuit makes would be eye opening for alot of people I think. More/less bass into clipping etc... Thanks for the awesome content Brian

"So you're gonna notice this is - well you may notice, you may not notice!" That pretty much summed up the main point of this video. And for the record, I loved it. There were some tiny differences between the op-amps, but as far as which one to pick, I'd be far more interested in how reliable they are compared to what little sound differences there are.

You gotta love that the pink LED sounded more different to the other LEDs than *any* of the op amps did among each other.

I've had thoughts of designing some of my own pedals, beginning with overdrives. This is a great place to start. I loved the comparison of the op-amps and diodes. Well done, and thank you.

Im not a big gear head electrical guy, but I love tone, play guitar, and love your pedals so I find it very interesting how you go about searching for the ultimate tone! I think the bread board video's are great to throw in. Ive been sub'd for awhile now and love your channel. Keep up the good work. Thank you so much Brian!

This is so cool. I've really been loving these breadboard videos recently. Could you ever make a video showing us the whole circuit and what everything in it does?

The Red LED's sounded the best IMO. Obviously the only part of the tone that matters. Ill never buy a pedal with Blue LED's again. Haha, I love this Mr. W, I just got your Euphoria pedal, and absolutely love it. Amazing tone from such a beautifully presented box.

I love this type of demo. As an EE and guitar player I find it very educational. Thanks & keep it up!

(Orange was a favorite)Diodes and hitting the circuit with the boost was the most dramatic of the changes. I could tell that there was some tightening of the frequencies when using the expensive op amps -but not by a lot. Didn’t care for the germanium diode clipping. Interesting enough to want to get a bread board and goof around. Reminds me of my electronics kit in the 70’s when I would make noise generators. You truly have the more interesting pedal oriented RU-vid channels. I know it’s older content but I’m glad that you’ve continued this take on pedals. Nothing needs more demystifying than pedals. I wish a boutique amp builder would do the same with amp circuits. You would be a great guest on ‘The truth about Vintage Amps’ to talk about my problem-what makes a good pedal platform. I have amps that sound so so but put a pedal in front and it roars and conversely, a great sounding amp that sounds like dog doo as soon as you hit it with any kind of boost with the exception of a tube screamer types of pedal.

Great demo, really demystifies some of the stories around ICs and diodes. I ended up with some leftover parts from a synth build and thought maybe I could build a distortion pedal, then I got really wrapped up in trying to figure out which pedal uses which chip and how they're wired, worrying if these spare parts will do the trick. You helped me realize I should just build it on a breadboard, test it out and see how they sound instead!

Honestly I really liked just the op amp clipping... sounded fat and rich... Love these type of videos. You hear all the terms when people flog you pedals at stores and online (no disrespect intended Mr Wampler), but to actually see the difference (or how little difference in some cases) these tiny changes make is an eye opener. Proper pedal nerd territory ;oD

This video is fantastic. I really enjoy your channel Brian.

Thanks Brian, i really enjoy mucking about with guitar effects and find these kinds of vids fascinating.

Hey Brian...I have to say...I truly enjoyed this clip....awesome job...:)

This is no way boring, I don't get much of this stuff, but you are clear and help me understand it better

Brian, this is one of the most informative videos you have made in dispelling all those "pedal myths" that are out there! -a former electronics technician

Really insightful little demo. Thanks Brian.

You're more correct than the cork sniffers want to admit. I have an original Blues Breaker pedal I put a socket in for just this purpose. It came with a TLO72 but I drank the 4558 Kool-Ade and couldn't let myself sleep until I exhausted all options. I tried almost every one you did here and to my ears the only difference between just a few of them was that some seemed to have mixed more or less direct signal into the overall tone. For that particular pedal a TLO82 was what I liked most.

To anyone who would to understand what's going on here in scientific terms: start by googling "frequency response" and "bode plot". The frequency response of a pedal describes how a pedal will change the input signal as a function of frequency. Certain pedals will attenuate/amplify certain harmonics that result in "brighter" or "darker" tone. Changing the harmonics in a specific way creates "distortion", look up "square wave" for this. Distortion is essentially just making the signal more square-like. For this experiment, if you look at the datasheets of several op amps you'll find that most of the characteristics are the same or very similar. What really matters is the surrounding circuitry. Specifically, filtering caused by capacitors and resistors (look up high pass filters, low pass filters, bandpass filters) This is what determines the "color" of your sound. Diodes can also change the sound a little bit depending on where they're placed and their forward voltage. Most of the diodes found in pedals will have very similar characteristics though in which case location matters more (soft clip vs hard clip). Clipping cuts off the peaks of the signal. Hard clipping makes a straight cut which makes it more square and "harsh". Soft clipping is a rounder cut which provides a slightly less harsh distortion similar to how an overdriven tube works. Hope this helped!

I have been tuning in for a few weeks now after 2 successful amp builds (MOJOTONE)..I really appreciate the sharing of your knowledge.. I had a Danelectro Fab Tone which came with a used amp I bought years ago.. I had NEVER used the pedal due to the EXXXTREME drive... I watched several of your videos and I was able to tone that pedal down on the circuit board to where it is usable with my 5E3 amps.. Many Thanks Again! Your playing ,sound , and tone are awesome by the way!!!!

The Burr-Brown OPA2134 sounded really cool, the pinch harmonic you got had that character that I really like. Very subtle differences though. Love this channel btw!

I don't know the first thing about electronics & can barely solder a pickup in place, but I found this quite intetesting.

Thanks for making this, I do find this very interesting.

Fun and informative video! I did an experiment once with a RAT-ish circuit with different clippers... from diodes and LED's JFets and MOSFET's, and combinations of these... and a switch to place them in either the common position after the op-amp or in the feedback loop. This makes a very versatile dirt box, where the position of the clippers makes a lot more difference then the kind of clippers It resulted in a very cool pedal that i still use a lot.

I may have already commented on this video, but screw it! I love what Brian does with these videos! I always find myself back to Wampler vids when looking for pedal content. Yeah, I watch them multiple times, what of it? :) Great dude, great sense of humor/down to earth and tons of great info! Thanks Brian!

Hmmmm, I think, at this point, it's in the fingers. That being said, I came here because of your pal Josh from JHS. I love this stuff, Mr. Wampler! (and, I think you may be a hair better guitar player:).

not boaring at all.solid help Brother.God Bless

Great video to illustrate how it's all the parts of playing that make the sound. From strings, pick, brain, hands and all in between. Fun in a electronic nerd kinda way. I liked it!

Very cool, great insight into how different diodes effect the tonal quality of an overdrive chip.

I'm going to add to your information. The most important feature in the quality of an op amp is the Slew Rate. Slew Rate is the ability of the amp to increase voltage to incoming changes. The 741/1458 is .5 to 2 micro volt Slew Rate. The TLO72 is 7 micro volt Slew Rate. The 5532 is 5 to 13 micro volt Slew Rate (Varies by manufacturer) All the Japanese chips, JRC, NEC, NJM are very old license built chips and fall into the 1 to 2 micro volt Slew Rate range. The higher the slew Rate the more vibrant and detailed the sound will be. The lower the Slew Rate, the more dull and distorted the sound will be. The sound is distorted because the op amp is being fed with too much audio signal and it can't process it, and outputs a distorted signal. Anything additional in the audio line will only color the sound.

"I know this isn't the greatest circuit in the world..." - *Procedes to play some amazing sounding tones*

Loved it. It was a great test for my ears I heard some slight differences in the op amps. Really interesting thanks Brian ;)

Very good test. Minor dfferences. When I was at the techinical school 35 years ago we had to do these tests over and over. It's nice to see you still using that good old breadboard for clearing things up.

Wow, so many op-amps to choose from! When I was learning electronics back in the 70's there was the 741 and that was about it! What an exciting time to be alive!

Anyone else think it would be really cool for some pedal maker to use a more sensitive LED clipping diode, and poke them through the housing as part of the aesthetic of the pedal?

I'm starting out learning about guitar pedals, and this video was super helpful. Thank you so much.

Fun and very cool. I'd be interested to see the same type of tutorial demonstrating how different component values effect a circuit's EQ stage. Maybe the Big Muff/DS-1 type tone control. ... Thanks for putting in the time on this stuff.

I caught my girlfriend with an LM324. She had to go.

I really enjoy these types of videos.

Thanks for taking the time to make this video, it's one of the most honest comparisons of components I've seen. Keep telling it like it is Brian!

Awesome video! I love hanging out in your shop like this!

Working on my first build of an overdrive. I really like how the OPA2134PA sounded. Thanks for this video. I work in electronics as a control technician. I play guitar for fun and decided to pick up pedals as a fun hobby.

Keyboard player here, im halfway through the video and i gotta say, these all just sound like *a guitar* to me. not sure if that was the point of the video, but thats all ive gotten so far.

Love your videos, such delightful insights.

great video Brian, really like your honesty and patience in making this video to clarify these things up. Is there any chance you might have a tutorial on how to build a circuit like you created in the video? FWIW I really digged the red LED sound.

I miss messing with op-amps and building circuits. I got Craig Anderton's book and built a bunch of his stuff. Later I got a job repairing music gear at a shop. Great video.

LM833 and opa2134 sound different to my ears in a pleasant way, the rest... pretty the same. Thank you for demoing Brian!

super great video! I just bought the Wampler Dual Fusion and am really enjoying the world of Wampler...

Much like you do at the end, I put a good old LPB1 pedal in line before my OD to just add some more saturation with just a little more volume for solos. Always fun playing with transistor and op amp circuits!

that is seriously the best guitar gear video I have ever seen. case closed, myth busted, feelings hurt.

The OPA2134 sounded the best. Most sounded pretty much the same but there is a dynamic with that chip that sounds rather good.

Incredible demonstration here. This is why the internet is so cool. Super appreciative of you setting this up (also absolutely love everything wampler I've ever heard fwiw)

JHS Pedals sent me here. I really enjoyed this. I got a huge smile on my face when you put the LEDs into the circuit. Very cool stuff.

What if you used white LEDs and painted them purple? How would that sound? ;-)

It could just be the iPad speakers, but I didn't hear any difference at all in chips. I've swapped chips in a Boss EQ before though, and the one huge difference I heard (and result I was after) was a noticeable reduction in white noise when the pedal was on. There are differences in chips, but tone is not where you're going to notice it. Noise and headroom are going to be the difference to listen for.

Thanks as always for the informative video!

Very informative & cool video! You've got a new subscriber, been meaning to for a while actually :-) I really dug the sound of the white LED's! I pretty much couldn't tell any discernable difference between the op amps.

Brian, from this day onward, I demand that all your pedals take the diodes you called "fancy schmancy." No more cutting corners, please. ;)

Ain't got a clue what's going on in here, but, you build them, we buy them!

I myself liked the blue LED's as clipping diodes, and the clipping of the op-amp itself. I use an Airis Effects Savage Drive, and it has no clipping diodes, all the clipping comes from the op-amp. Sounds great!

I like pink LED by hardclipping, they are flashing so nicely 🤟 I really like the soft clipping. With booster in front you can control the soft clipping very well 👌

When you're designing a circuit, how do you prevent your ears get fatigued? And, how do you avoid duplicating the sound of previous designs?

Wow! After being brainwashed by the JRC4558D mantra, I was about to pull out a JRC2043DD out of my early 1982 TS-9. Not any more... thanks for the vid!!

This is like an amp shootout!!!. Very good and informative!

Wow that was fun! What would soft-clipping & hard-clipping sound like together I wonder? Thanks for taking the time to do this, it was great!

didn't understand anything at all, but cool!

the first "expensive" one sounded better than the second one, but they're all pretty much the same. For the really lo-fi gritty ones, I like the LM386. The 4558 sounds pretty damn good too. It's a super subtle difference, and I bet some of these vary equally much within their models as they do compared to other chips. In my ears, it's mostly about clarity, apart from the gain levels of some of them. Great video!

this was not dull at all thanks for sharing this you are the man

legend! tnx for doing this ! (its very educational for young ones and new players)

how about some circuit schematics i've got plenty of parts!

Maybe you should sell a Wampler bread board kit. It could 2 or 3 choices of OP amp etc. so we can experiment ourselves.

I love how your choice of chips in the first half was all over the shop, showing how jFET/BJT input and current handling capacity has nearly bugger all impact on tone in a guitar effect pedal. The BJT input chips tend to be lower noise, which can be important in a studio mixer with dozens of channels and the higher current OPA chips drive lower impedance loads (headphone amp) better, but if you're talking distortion pedals, just use TL072s; they're common as clarts and they get the job done.

I understand electronics and play guitar and find this with the different op amps very inspiring,, cheers.

Anybody else really shocked at how different the sound was with different color LED's? I know nothing about this stuff, but that's probably the last thing I would have thought to make a difference.

I've been standing in front of a Big Marshall for too many years. It all sounds the about same Gaaaaaaaaaaaaaa

Great for me man. Thank you! Just bought a breadboard so i'm excited to see what I can do

I liked the 2134! God I am such a dork. Nice vid, Brian. Just picked up a 1st Gen Ego Compressor. Having fun playing with that and learning how to use this effect. Thanks.

should let people vote on components and then make a pedal based on that for sale

Wish he did back to back comparisons with the same riff fed from a looper pedal. It's impossible to hear the difference with so much time and talking between.

Great video! I always liked my 81 ts9 with the 2043 vs the 83 4558.

I liked being able to see the LED clip lighting up. I was thinking about a capacitor and pot in the feedback loop as well like presence..