Are they the same or not?
They may not sound the same but they will work.
Aharon
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
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.
Quote from: Brian Marshall
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.
Quote from: Steve C
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
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.
Quote from: Steve CQuote from: 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
[sorry double posted, see below]
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.
Quote from: 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
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.
Quote from: anonymousexperimentalistQuote from: 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.
Quote from: Brian Marshall
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
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.
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.
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.
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
Quote from: Jay DoyleThere 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:
(http://www.pisotones.com/Articulos/imgs/Mi-JRC4558-DD.jpg)
Quote from: Manolo DudesQuote from: Jay DoyleThere 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?
Quote
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
Quote from: Dai H.What does the "JRC4558" above look like and what package does it come in?
I think i've got one of those in my parts box. I seem to recall it's an old one with shiny-sharp-edged package and one big vertical white line on the left side. I'll take a photo if it's still there.
Rats!!!... I cannot edit my last post :evil:
I only want to add that it's a regular 8-pin DIP package.
P.S. Is the "delete post" option disabled?
Follow these simple instructions:
Scroll down and right all the way
Look at the bottom right of your window
Now you know :)
lol OH DEAR GOD.... i can't even finsish reading this.... i got one jrc4558 left.. not a new one, but an old one laying around for somethine. do you want it.. send me an address and i will give it to you.
Quote from: smoguzbenjamin
Scroll down and right all the way
Look at the bottom right of your window
:oops:
Quote from: Manolo DudesQuote from: Dai H.What does the "JRC4558" above look like and what package does it come in?
I think i've got one of those in my parts box. I seem to recall it's an old one with shiny-sharp-edged package and one big vertical white line on the left side. I'll take a photo if it's still there.
Well, I suppose that could've been called a "D", but just not marked as such, or maybe it was just "4558". I've seen the ones you're talking about on ebay before. Somebody was trying to unload a whole bunch of them, as I recall.
Dai
I agree with Dai, it must not have been stamped that way, but it had to have been ordered that way. I don't think I have ever seen a 4558 in a metal can package (I can't imagine what that would fetch on ebay) but it must have had package options.
Here is what Walter Jung says about it it
The IC Op Amp Cookbook:
Quote The RC4558 (Raytheon, 1974) is also a popular device. Although the RC4558 is not a "true" 741 in the sense that it uses nonidentical circuit topology, it nevertheless is considered functionally so by many. It is a dual unit, offered in the same pinout as the MC1458 (this 8-pin dual-amplifier pinout has become standard.
...the major difference from a 741 circuit is use of pnp input transistors, as opposed to the npn's in the 741. This, of course, reverses the direction of the bias current in the source resistance(s), which may affect the performance of some circuits. It is for this reason that the 4558 (and relate units) cannot be termed a "true" 741, but equals or betters the performance of the 741 in other regards.
The RC4558 features improved performance over a standard 741 in terms of noise, slew rate, and bandwidth. A great many other op amps are patterned after the pnp-type input topology, and it appears in quad form as the RC4136. The RC4136 was the first quad op amp to appear on the market, and it enjoys wide popularity and multiple sourcing, as does the 4558.
[/i][/color]
Random facts about a little chip for your Friday...
Jay Doyle
Quote from: brettChip 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).
Chip type does make a difference, I've tested JRC's vs. TI's and they sound slightly different.
But the original question was about package type, not chip type.
Doug
Quote from: Brian MarshallI have a bunch of JRC4558D's. I was just wondering if i made a clone if it would be authentic.
And what does "authentic" mean to you? Do you possess an Ibanez design specification for the 808? Doubtful. "Authentic" in what way?
Seeing as how they changed chip types throughout the evolution of this product, I'm curious as to what anyone would define as "authentic" wrt this product.
Doug
Thanks for that tidbit Jay. The 4558 doesn't seem bad for audio, IME.
Quote from: Jay DoyleI agree with Dai, it must not have been stamped that way, but it had to have been ordered that way.
I've got the data sheet, and it does mention the suffix/package. Perhaps, the earliest ones didn't, but you'd have to see it to confirm that.
Quote
I don't think I have ever seen a 4558 in a metal can package (I can't imagine what that would fetch on ebay) but it must have had package options.
I have another one. Motorola, I think it was. Some of the ones in efx. do (or did) come in cans. 741, 308.
If anyone notices a difference with some of the caps, I'd be interested in your observations. I'm talking about the input .02, .047 near fdbk. lp., and the .1uF towards the output. What I mean to say is, if after trying an original type chip and not getting a cloned 808 sound, maybe try the caps. Or in modded reissues.
Dai
QuoteI have another one. Motorola, I think it was. Some of the ones in efx. do (or did) come in cans. 741, 308.
I knew about those, I assume that the 702 and 709 did as well as they were the first ones, I also know that the 3080 OTA came in a can as well, some of the early dynacomps had them in a can. Are you saying that you have a Motorola 4558 in a can? interesting...
The ouput buffer is mounted on the output jack board in the TS7. People the vox valve tone had the rc 4558 stock, The two 808 I have seen inside had jrc4558s.
The new and older jrc 4558 don't sound different to me the letters at the end might just be grades for noise. That said damaged chips might sound bad. The input diff pairs can be hurt by heat and static and current surges. This will change the overload recovery and noise.
John Greene did alot of work finding info on the jrc4558. Don't forget that people that have a bunch of one type to sell might state thing on boards alot of people don't test the statements and if the statement get repeated enought it seem to become a fact.
I have been in many TS and have modded them in different ways. I have two VVTs three ts7s,1 ts5. all modded I have modded over 10 TSs for friends. IMO the magic of the ts808 is the tant caps. The closest I got was with a type of film. The orginal 808s tants seem to have just the right amount of "grit". IMO the VVT tants come the closest.
Don't get hung up with the chip. chips are cheap try them. I don't hear much difference with different chips untill tyhe petal gets a large signal and/or the gain and tone pot is up all the way. This is with upgraded caps.
When someone want a TS mod I place all my ts type petals(6) in a room and have the person bring there own amp and guitar. The petals are not marked. I leave the room so they can't see me and don't talk and let them pick the petal they like I them put that mod in there petal.
Most of the time stock gain the 4558 is ok:however at higher gain I like other chips.
I have posted alot in the past about chips I like.
Gus
This thread is getting long-
maybe someone said this already-
JRC4558DD-
The 2nd "D" stands for "selected low noise"
And it really does have less "hiss" at max gain.
This info from John Greene- back in the early days of Ampage/Arons forums.
Ed R.
Quote from: Ed RemboldThis thread is getting long-
maybe someone said this already-
JRC4558DD-
The 2nd "D" stands for "selected low noise"
And it really does have less "hiss" at max gain.
This info from John Greene- back in the early days of Ampage/Arons forums.
Ed R.
woo hoo those are the ones i have...
Quote from: Jay DoyleQuoteI have another one. Motorola, I think it was. Some of the ones in efx. do (or did) come in cans. 741, 308.
I knew about those, I assume that the 702 and 709 did as well as they were the first ones, I also know that the 3080 OTA came in a can as well, some of the early dynacomps had them in a can. Are you saying that you have a Motorola 4558 in a can? interesting...
Yeah, I bought it because it looked unusual.
QuoteThe new and older jrc 4558 don't sound different to me the letters at the end might just be grades for noise. That said damaged chips might sound bad. The input diff pairs can be hurt by heat and static and current surges. This will change the overload recovery and noise.
I guess that could explain it when some people hear a diff. even with the same jrc4558, I suppose.
Dai