JRC4558 AND JRC4558D

[Brian Marshall]

Are they the same or not?

[Aharon]

They may not sound the same but they will work.
Aharon

[ExpAnonColin]

The difference between an NJM4558 and a NJM4558D is that the 4548 refers to the specific dual-op-amp chip design in general, while the 4558D is a certain "shape" of it... The surface mount one is NJM4558M and the horizontal-mount one is 4558L.

-Colin

[Brian Marshall]

ok that didnt make any sense at all.

anyways i'll give you a little background on why i am asking.

There is an amp shop in my town that mods TS5's, and TS9's to 808 specs.  I was asking the guy last time i was in there (about  a year ago) where they got the chips, and he said that they used jrc4558d chips.  I told him that i thought they were a different chip, but he said that some TS808's were sold with that chip... I also noticed that the jrc4558d is in my TS-7.

I already know that anything that starts with NJM4558, and the jrc4558 are totally different in sound, and that the NJM chips are thought of as crappy.

I'm not asking about the prefix.  I'm asking about the suffix.

[Steve C]

I already know that anything that starts with NJM4558, and the jrc4558 are totally different in sound, and that the NJM chips are thought of as crappy.

I'm not asking about the prefix.  I'm asking about the suffix.

JRC stands for Japan Radio Corporation, they changed their name to NJR (which is New Japan Radio).  NJM is one prefix they use on their chips now.  Same company.  The two chip where RC4558 (texas instrument chip) and JRC4558 (Japan Radio Corporation).  

The suffix has to do with the type of package the chip is in.  It comes in several different packages.  The "D" is for the standard 8 pin DIP package.  Go to http://www.njr.com/ and find the datasheet for the NJM4558 chip and see for yourself.  

The NJM chip is the same chip as the JRC chip, same company making the same chip.  Mouser sells them for $0.22.

[ExpAnonColin]

JRC stands for Japan Radio Corporation, they changed their name to NJR (which is New Japan Radio).  NJM is one prefix they use on their chips now.  Same company.  The two chip where RC4558 (texas instrument chip) and JRC4558 (Japan Radio Corporation).  

The suffix has to do with the type of package the chip is in.  It comes in several different packages.  The "D" is for the standard 8 pin DIP package.  Go to http://www.njr.com/ and find the datasheet for the NJM4558 chip and see for yourself.  

The NJM chip is the same chip as the JRC chip, same company making the same chip.  Mouser sells them for $0.22.

Yes, exactly... in this case the suffix determines the package (not always true).  If you want a datasheet to check it out, let me know.  I'm also reasonably confident that JRC is Japan Radio Co and NJR is New Japan Radio co.

-Colin

[Mark Hammer]

My gut sense is that the tolerances of the other components in the circuit play as much a role, if not more than any differences between the chips noted.  The diodes could have higher and lower clipping thresholds, matched or unmatched ones, the feedback and lowpass filter caps can vary by 20%, and the gain-setting resistors are 5% tolerance.  When you consider the vast range of permutations and combinations, the sensible thing to do is to stick a socket in there and keep swapping chips until you find something you like.  Many folks have raved about chips that leave others scratching their heads, so I would be very surprised if merely identifying the "proper" chip suffix makes the difference you expect to emerge.  Ibanez used them for the same reason everyone else did for decades: they're cheap.  As for the person doing the mods, the best thing they can say is that it is done to 808 "specs" using the nominal values of the components.  I'm pretty sure that no one sticks it on the scope and confirms that the waveform iteself meets specs since no one knows what those specs are.

[Brian Marshall]

The NJM chip is the same chip as the JRC chip, same company making the same chip.  Mouser sells them for $0.22.

OK, but still not answering my question.... I already know the history of the name change.  I want to know if there is a difference in sound between the JRC4558, and JRC4558D.  I dont care about the packaging, i want to know if a TS clone with an JRC4558D is authentic, because all the information i see lists a JRC4558.  Are they just leaving the "D" off?

anyways getting back OFF THE TOPIC the chips with newer prefixes have a bad reputation, and from what i understand are manufactured differently.  I'm not interested in a spec sheet, i want to know about the TONE.  DONT SPEND TOO MUCH TIME ON THIS LAST QUESTION, INFACT DONT EVEN ANSWER IT, BECAUSE I ALREADY KNOW THE ANSWERS I AM GOING TO GET!!!!

anyways.... if the JRC4558d was an 8 pin dip... what the heck was a JRD4558?

Brian

[Jay Doyle]

[sorry double posted, see below]

[Jay Doyle]

You are not listening (reading).

There is no JRC4558 without a suffix. Never has been never will, there needs to be a suffix of some sort to denote the package. the "D" is the only one that will fit in your circuit because it is an 8-pin DIP, so like it or not your are stuck with using a "JRC4558D".

As for the newer manufacturing methods, yeah they may be different but no different than how they were 20 years ago from day to day. Silicon is "grown" into the chip form to produce the circuit and all chips have tolerences just like resistors and caps, you are as likely to find a "good" one now as you were back then.

Don't spend too much time worrying about this, Mr. Hammer is right, other things can have as much if not more of a difference in the sound, in fact changing the output resistors to 808 specs made more of a difference to me than the chip change. The reason upgrades cost so much is that people fall into the "4558 mojo" trap.

LF412, TL072, RC4559, LF353 all sound good, plus many more.

[ExpAnonColin]

anyways.... if the JRC4558d was an 8 pin dip... what the heck was a JRD4558?

Brian

...for the third time, the JRC4558 refers to the chip itself, while the "D" refers to the chips packaging.  Look at the datasheet.  The "D" is the most common for us because we don't use surface mount chips or horizontal mount.  When someone is saying JRC4558 without the D they're saying the packaging doesnt matter (which it doesnt.)

-Colin

[brett]

Chip type (not package) DOES matter quite a lot, and my testing indicates that thre's MUCH more variation from manufacturer to manufacturer than from chip to chip (of a given type).

But don't believe me (i might be some bullshit artist playing on the internet).  Get a friend to randomly swap (while you can't see) between an NE5332 and a JRC/RC/NJM4558.  One will usually be heaps better than the other.  If it's not, get a hearing test.  I haven't checked the CMOS input twin opamp chips myself, but I'm told by those who know that they're good too.

[Brian Marshall]

anyways.... if the JRC4558d was an 8 pin dip... what the heck was a JRD4558?


Brian

...for the third time, the JRC4558 refers to the chip itself, while the "D" refers to the chips packaging.  Look at the datasheet.  The "D" is the most common for us because we don't use surface mount chips or horizontal mount.  When someone is saying JRC4558 without the D they're saying the packaging doesnt matter (which it doesnt.)

-Colin

ok look back at your original post, and tell me it was clear...   you started talking about the newer chips with a different prefix, and the f'ing typo'd the part number right afterwards.  Then you throw in a million answers about other OTHER COMPONENTS, and PREFIXES from other people.  That wasn't what i was aking about...   Sorry the word -shape- in quotes doesnt give me a clear picture.

I have a bunch of JRC4558D's.  I was just wondering if i made a clone if it would be authentic.  I'm not talking about picking parts for tone, but faithfully reproducing the original...  I know that other parts produce the tone.  Honnestly if i wanted to use my favorite op amp it would be a TL072, but that isnt the point.

oh and btw i posted the last response while mark and colin were posting, so i hadnt seen their responses yet.  i was at work, and it took me a few minutes to type it.

[ExpAnonColin]

ok look back at your original post, and tell me it was clear...   you started talking about the newer chips with a different prefix, and the f'ing typo'd the part number right afterwards.  Then you throw in a million answers about other OTHER COMPONENTS, and PREFIXES from other people.  That wasn't what i was aking about...   Sorry the word -shape- in quotes doesnt give me a clear picture.

I have a bunch of JRC4558D's.  I was just wondering if i made a clone if it would be authentic.  I'm not talking about picking parts for tone, but faithfully reproducing the original...  I know that other parts produce the tone.  Honnestly if i wanted to use my favorite op amp it would be a TL072, but that isnt the point.

oh and btw i posted the last response while mark and colin were posting, so i hadnt seen their responses yet.  i was at work, and it took me a few minutes to type it.

Yeah, no problem, I was being unclear because last time I told someone what the suffix of a chip meant I was wrong and someone totally tore me a new asshole for it.

Hope the mod/clone goes well...

-Colin

[Brian Marshall]

im not sure exactly what im going to do yet.  i have a couple of TS7's that already have a lot of the correct components on them, but i cant put the output buffer on the board.  I think i'll hot glue some perf board to it, but maybe i'll build it from scratch.  I am still prety sure (at least from the rumors i hear) that the NJM, and NJR chips sound different... everything i read says so anyways, but I dont have any of the "N" chips, and JRC4558D's arent that expensive.

[Mike Nichting]

Hey Brian,
yeah I have heard the new chips sound bad too. Haven't tried any because I like the way my RC4558P sounds. I use the Texas instrument 4558 because that was in the original 808. The JRC4558D was in the original TS9. They also used another chip that I can't think of right now. It is a 74448 or something like that,who knows.
The JRC4558 sounds a little more mellow to my ears than the RC4558P does and the TL072 sounds a bit cleaner, less distorted to me but then the TL072 wasn;'t used in the TS.

If you want to clone the original 808 then you should get a Texas Instruments RC4558P IC. They do sound different than the JRC4558D that was used in the TS9's and other TS's.

I'm not sure what the "P" stands for if the "D" stands for DIP. Unless I misunderstood.

So to sum this up. JRC4558D= TS9/ RC4558P= TS808.

Good luck Brian.

Mike N.

[Mike Nichting]

Brian, after all that typing I forgot ot say this. I have seen and swapped the JRC4558's with a "D" after them and without. Now you go back to Mr. Hammers post. Unless you are tryting them in the same pedal it's near impossible to "hear" the chip due to the componet differences.
I think the JRC4558's all sound damn close to my ears.

Hope that helps a little :-)

mike N.

[Dai H.]

I think "JRC4558" is more the common use term from the Tube Screamer popularity, so "JRC4558" and "NJM4558" are the same thing. But I believe we're talking about the older ones in the shiny black package, correct? AFAIK, the new package appeared in 1990. It's not a "reissue" chip as I see on some sites, it's just a newer version (i.e. JRC didn't stop making their 4558 and all the sudden decide to reissue it again--it's just a cheap gen. purpose opamp, after all). If you look at a bunch of semiconductors of different ages, then it becomes apparent that it's quite ordinary for the manf. to change them for whatever reason (better consistency, lower defect rate, whatever).  If you want to try to reproduce the original, then I guess the best thing to do is to get the same parts when you put your clone together. I would copy the caps too, they seem to make a diff. But ultimately though, since this is subjective, you just have to try things out and decide for yourself if there is a point to all that effort. Luckily, I haven't had to pay $15 or whatever for the old ones, but maybe if you really want to find out, that's the price you'll have to pay (unless you can find one in a dusty bin or scavenge some out of some older equipment).

Dai

[Manolo Dudes]

There is no JRC4558 without a suffix. Never has been never will, there needs to be a suffix of some sort to denote the package.

I'm afraid that's not true. I have tried several JRC4558x in my preferred  TS clone. I've tried:

JRC4558
JRC4558D
JRC4558DD
JRC4558DX

And... I know it's a dead-end discussion and it may be all in my head, but I hear slight differences between them. I personally favour the DD version. Look at the photo of the guy that actually sits inside my own TS clone, scavenged from an old crappy stereo:

[Dai H.]

There is no JRC4558 without a suffix. Never has been never will, there needs to be a suffix of some sort to denote the package.

I'm afraid that's not true. I have tried several JRC4558x in my preferred  TS clone. I've tried:

JRC4558
JRC4558D
JRC4558DD
JRC4558DX

What does the "JRC4558" above look like and what package does it come in?

And... I know it's a dead-end discussion and it may be all in my head, but I hear slight differences between them. I personally favour the DD version. Look at the photo of the guy that actually sits inside my own TS clone, scavenged from an old crappy stereo:

Actually, I've heard some people say this, but personally I've never noticed a huge difference among the old ones. BTW, there is also a 4558T which comes in a metal can and has gold-plated legs, as well as ones in the regular package with "A", "E", and "M" suffixes. The "T", being the rarest, has the smoothest distortion and the tightest lows, as well as a 3 dimensional presentation... (kidding...)  :wink:

Dai