The neverending story of the JRC4558D!

[12Bass]

Interesting thread... 

What I find somewhat curious is comparing the sound of op amps in a distortion-producing device.  I have reliably heard differences between op amps, though usually when comparing in a clean amplification scenario.  I suppose that pushing things into distortion may reveal different characteristics.   The JRC4558D is by no means a high fidelity op amp, as there are many superior parts available today.  If seeking a more open sound, I would probably try something better.  Can't say I've heard any difference between two specimens of the same part, however.... 

[zombiwoof]

OK, I think it is time now to hook up this great sounding overdrive pedal between my guitar and amp, krank it up and PLAY!

Amen to THAT!!! I still can't figure out the difference between Coke and Pepsi!! Old, new, borrowed, or blue, just go with what sound good to you. I have an old Korg SDD2000 board, which had 5 JRC4558 chips on it. One "DD", and 4 "DV"'s. I've swapped them all around in different pedals, and I never really could tell any difference in the sound between them and newer 4558 chips. Then again, playing guitar at insane sound levels for years has effectively left my kids repeating themselves often at times, so I doubt I would pick up on the subtleties 

Cheers,
Dino

I think the "DD" version is supposed to be less noisy than the "D" version, otherwise I think they are pretty much the same.

Al

[brett]

Hi

Can't say I've heard any difference between two specimens of the same part, however.... 

Different electro caps (same brand & spec) can cause differences in filtering applications.  Typical tolerances are +50/-10 %, which is enough to shift a roll-off frequency by half an octave (e.g. 10 kHz vs 15 kHz).

Going back a few years, it was unlikely that two Ge transistors would sound the same (except when used in a buffer). Variation was rife, and components would sometimes be DOA.  (OK, stop the old guy's rant now)
cheers

[runmikeyrun]

hey, if you hear a difference, and it sounds good, then go with it!

[R.G.]

There was

=> ONLY ONE <=

batch of JRC4558DGC chips ever made. These had platinum and gold diffusion instead of the normal dopants. The yield from the wafer was 23 chips, and I have 19 of these. They make any pedal that uses them sound like either the angels singing or the devil snarling, depending on your mood. They're actually mood sensitive, and they can literally reach into your fingertips, using the electromagnetic fields they transmit down the shield of your guitar cord and PULL the magic music out of you, making you (at least temporarily) a better guitar player. I've scoured the world to be sure these don't fall into the wrong hands.

I will only sell two of them. Let the bidding begin.

[Rectangular]

R.G., et al :

I find this long going argument annoying for a couple of reasons. most circuits where people claim to be hearing magical differences between 4885's simply aren't very interesting circuits, and I agree that if you did a double blind test, the distribution would be random.  overdrive ? distortion ? I've done a lot of chip-swapping with new chips, NOS chips, vintage chips, pulled chips... at best you'll hear some treble/bass differences, but nothing you couldn't tweak to on the pedal or guitar tone controls already.

however, there is one instance where I has seen a difference, and this was with the Electro harmonix polyphase. I have a original vintage one, and a clone I made. they sound sort of similar, but not really. when you crank the feedback up on both units, they have a completely different timbre. I concede that this may be due to some other circuit elements that I'm not considering,  but really,  the circuit is a cascade of 5 4558 chips functioning as allpass filters for the phaser,  the rest of the circuit is just lfo/envelope generation.

the only thing I haven't done is  try to desolder the 4558s out of the vintage pedal and place them into my clone. I would hate to damage them in the process and lose the sound of the unit.

[R.G.]

I find this long going argument annoying...

You think YOU find it annoying?

[Renegadrian]

I like a regular 4558 inside yjm308! no mojo here!!!

[aflynt]

The brain of a musician is a moving target as far as testing is concerned. They will unconsciously adapt the way they play to produce the desired sound from different equipment. There are a number of factors that simply aren't measurable or controllable that will impede or assist in this adaptation. There's nothing wrong with focusing on the physics and theory of what is going on, and that will likely get you most of the way there, but ultimately the human factor is inescapable. I'm personally kind of torn on how I feel about this too. As a tech, I can't help but want to eliminate all of this superstition, but as a musician, I think it's actually part of what makes great music happen.

-Aaron

[edvard]

I'm torn as well.
I KNOW this stuff shouldn't make a difference, but (I think think I've said this 3 times now...) I recently built a TS808 for a friend and I tried different op-amps just for giggles and between most of them there was not much difference.
Subtle differences here or there, but certainly not enough to raise an eyebrow.
I don't like Tube Screamers anyways, so it didn't matter to me one way or the other.

Then I put in a old Raytheon RC4558 (not even a JRC  ) and man, it was DEFINITELY different.
Not like Marshall/Mesa different, but like 'I just changed my strings' different.
Trust me, I was NOT prepared for it and the only thing I could do is shake my head and box it up.
I didn't even tell my friend I had used a "special" part.
Better he remain blissfully ignorant...


For the record, I also agree with the human factor here.
Just a twiddle of the tone knobs here or there, less or more gain, chorus or phaser, and I'm a different guitarist.
Neck pickup with a treble boost and suddenly I'm Stevie Ray or my last name is Allman.
Turn the bridge pickup to 11, scoop the mids and I'm Dave Mustaine or Dimebag Darrell.
Give me a Wah and a Whammy bar and next time I answer the phone I'm all "Jimi speakin' baby..."

Um... not really.
But you get the picture right?
Even if it's all in your head, that's where it COUNTS, man!

I'm-a go play now...

[DougH]

I'm with Mark. Misappropriation of the cause of differences is one of the biggest fallacies in this area. Someone hears a difference between two things and mistakenly assumes that it is due to something that sounds and feels good and gives them a warm fuzzy feeling when they say it- and yet is completely wrong. And so, internet myths get started, spread, and the beat goes on...

Didn't we have this discussion 12 years ago or something?...

[aflynt]

Would it be possible to construct a "component test switcher" that would allow you to randomly switch between several components? I would imagine it to be a series of microprocessor controlled relays that would switch 8 inputs between several 8 pin sockets. There would be a "conceal" button that would randomly assign each component to a different activation switch, and a "reveal" button that would show the assignments on a lcd or something after you've finished testing. So you'd plug a connector into a socket on your pedal and then plug a bunch of alternate components into relay controlled sockets on the tester. Then you'd hit the "conceal" button, and test each sample device by pressing each of the activation switches, playing and listening. You'd write down your observations about each, then hit the "reveal" button at the end to find out which device was which.

-Aaron

[R.G.]

...ultimately the human factor is inescapable.

Even if it's all in your head, that's where it COUNTS, man!

Someone hears a difference between two things and mistakenly assumes that it is due to something that sounds and feels good and gives them a warm fuzzy feeling when they say it- and yet is completely wrong. And so, internet myths get started, spread, and the beat goes on...

Didn't we have this discussion 12 years ago or something?...

Back when industrialization led to trying to figure out how to make workers more productive, when they figured out that making a guy carry 100 pound tubs of hardware to his work station and pull the work over to him by hand, after they had done the obvious stuff like making the work less tiring and the environment more comfortable, they dug even deeper into how to make the workers more efficient.

A notable string of studies looked into changing lighting; productivity went up. Then they changed wall paint color; productivity went up. Then they changed... to shorten this, practically everthing they did mad productivity go up at least a tiny bit. It took a while, but they finally figured out that if the workers knew you were trying to help them by changing something, they thought they could work better, and so they did.

It's the old idea that if you really believe you can do better, you can. This is the origin of a huge amount of human behaviour - sales motivation talks, coaches, cosmetics, and yes, to some extent the myths and legends of the JRC4558. If you think you sound better, then you do. You feel more confident and relaxed, and the music flows easier. Visions of Jimi, Eric, Yngvie, B.B., Django, whoever, dance in your head.

The only demonstrable magic that ever existed is and always was limited to being inside a human brain.

Would it be possible to construct a "component test switcher" that would allow you to randomly switch between several components? I would imagine it to be a series of microprocessor controlled relays that would switch 8 inputs between several 8 pin sockets. There would be a "conceal" button that would randomly assign each component to a different activation switch, and a "reveal" button that would show the assignments on a lcd or something after you've finished testing. So you'd plug a connector into a socket on your pedal and then plug a bunch of alternate components into relay controlled sockets on the tester. Then you'd hit the "conceal" button, and test each sample device by pressing each of the activation switches, playing and listening. You'd write down your observations about each, then hit the "reveal" button at the end to find out which device was which.

Yep, easy enough to do. But there are caveats, even here.

Something similar to this was done for hifi testing. When the Golden Ears found that they could not reliably distinguish golden sounds from brass sounds, they blamed the relays for "polluting" the sound and covering up the subtle differences, the "impure and excess" wires to/from the relays, the alloy composition of the solder, etc.

Notice that a good ear could tell the differences in the sound of the relays themselves clicking too. All clicks are not alike as to tone and loudness. The controller would have to do random testing order to keep the person listening from simply (and possibly unconsciously) memorizing the order of the relays. Doing a really fair test is not always easy.

[aflynt]

Something similar to this was done for hifi testing. When the Golden Ears found that they could not reliably distinguish golden sounds from brass sounds, they blamed the relays for "polluting" the sound and covering up the subtle differences, the "impure and excess" wires to/from the relays, the alloy composition of the solder, etc.

I can see how it would be impossible to convince anyone who was already inexorably vested in their superstition, but this presupposes that the components actually will all sound the same. What if you have components that could theoretically be audibly different and you would like a real world test of how those differences are perceived?

Notice that a good ear could tell the differences in the sound of the relays themselves clicking too. All clicks are not alike as to tone and loudness. The controller would have to do random testing order to keep the person listening from simply (and possibly unconsciously) memorizing the order of the relays. Doing a really fair test is not always easy.

Couldn't the relays be placed in a sound-proof box?

-Aaron

[WGTP]

What the hell, I'll add my 2 cents. First I did my own test several years ago and noticed that where I stood in relation to my amp made more difference than any of the op-amps.  So, if I didn't stand in exactly the same spot after changing them, they would all sound different.  Some were noisier and had more or less pleasant noise, some smooth, some harsh, some had higher gain than others and would cause the guitar to feedback sooner of latter.

Minimally educated speculation.  As long as things stay linear, I'm doubt I can hear the difference with my damaged old ears, but when things become non-linear, i.e. distortion, there may be differences in the harmonic content generated, i.e. harmonics/overtones, that I can hear.  Since different op-amps have different spec.s and respond to resistance, capacitance, transconductance, bias, etc., i.e. Circuit Design differently, (isn't' that why there are so many different ones) there may be something going on that is audible.  The different circuit design of the op-amps may distort differently, respond to overload differently, take longer to recover, etc.  Those are measurable.

I have noticed that a higher level of even ordered harmonics seems to add midrange for example.  I think I have a heard a swirl to the 4558 distortion that isn't present in some of the higher quality op-amps.  I'm probably not a good test subject though.  

[Paul Marossy]

What the hell, I'll add my 2 cents. First I did my own test several years ago and noticed that where I stood in relation to my amp made more difference than any of the op-amps.  So, if I didn't stand in exactly the same spot after changing them, they would all sound different.  Some were noisier and had more or less pleasant noise, some smooth, some harsh, some had higher gain than others and would cause the guitar to feedback sooner of latter.

Aha! Now I think you have hit on something that is for sure a reality.

[DougH]

It's the old idea that if you really believe you can do better, you can. This is the origin of a huge amount of human behaviour - sales motivation talks, coaches, cosmetics, and yes, to some extent the myths and legends of the JRC4558. If you think you sound better, then you do. You feel more confident and relaxed, and the music flows easier. Visions of Jimi, Eric, Yngvie, B.B., Django, whoever, dance in your head.

I know I play a lot better when I like the sound of what I'm hearing. That's a fact. So IMO people should use whatever they need to use to help them relax and enjoy playing more. If they want to believe in 4558's or anything else, it doesn't matter to me. Everyone's different, likes different sounds, has different preferences for getting them, etc.