JRC4558D Chips

[Fret Wire]

Re 4558s - Is there a place in the forum we could discuss/explain the myth of the JRC4558 on the beginners page, so new folk don't get conned/overexcited/etc.  In one sense, I guess Small Bear does this by selling them for a buck each.  Any other ideas?

That'd be a tough one. The boutique makers hyped the 4558 so much to sell their pedals, that it's pretty ingrained in people that your 808 clone has to have one to be "SRV in a box". As soon as one of the highly respected makers offers their's with a different chip, and the appropriate ad campaign ("if this had been around back then Stevie would have used it"), the others may follow (eBay too). Of course, then they'll claim to have some "special NE5532" with similar mojo. Actually, Keeley does state in his ads that he uses TI's RC4558. I guess it's a start.

Funny, the only way I can judge the effect of most of the mods is with the amp dimed at full gig volumes.

[brrt]

Well, Fret Wire, seems to me you did a pretty good job testing different mods  :lol:
Will you share your knowledge with us? What's the "best" OA in your humble opinion? Are there cool mods which have more influence than replacing the OA?

grt, Brrt

[petemoore]

Only ones I've tried are the 4558's [which all work well to me ears], and a TL072, also worked well, and an 5532, which worked well.
 I wasn't hurt by any of the "B"s in the A/b testing, TL082, TL062, still not 'bad' compliments to the circuits, just the top three seemed more fun to play.
  The 5532 might be too clean for some tastes.
 The TL072 sounds great, My TS has a JRC4558 in it, I hope that either is not noticed by or passes the Mojo test.
 I don't use TS's much, no, preferring generally TS on steroids sound of the SD-1.

[Transmogrifox]

Transmogrifox, would you care to share any of your TS mods with us??

I am very interested in the pre and post filtering etc.

Just curious bro ;-)

Mike Nichting

I have one simple drive mod on the web right now.  See the Fulltone Full drive (I think generalguitargadgets has it) for tone mods.

here's the drive mod.  This is what mine is modded as right now, using an OP275.

www.geocities.com/transmogrifox/TSdrivemod

The 10nF parallel cap is part of what I consider a "pre-filtering" mod, as it changes the 3dB cut-off of the highs boost.  It adds a little more depth/grind to the sound.

I also have another passive network that I was playing with in a different circuit.  If I remember, I can post that on the web.

Post-filtering things include making a TS with a tone stack from a Fender amp, or simply changing the capacitor values in the TS tone circuit.   It doesn't have to be complicated to sound good, so I don't want this pre/post filtering concept sounding like a mystical or "secret" thing.  Jack and RG have many suggestions for these kinds of mods.

I hope that page I posted is helpful.  I honestly think that's one of the best mods I have done to the circuit yet.  Enjoy!

[Fret Wire]

Nothing new about the mods, they've been around awhile on many forums. You have to figure out which mods work, either alone or together, for the sound you are looking for. Best, is best for your guitar/amp setup. Also, do you want to improve on the pedal's basic character, or change it completely?

As far as OA's? Replacing the original 7558 is a difference you can hear. After that it starts to get subjective, the changes are small. I tried two pedals for each OA to eliminate the tolorance difference in components. Then if I heard a difference in chips, I swapped the chips amongst the other pedals to test again. If I still heard a difference, then I decided there was a difference. Different guitars and amps too. Like I said, after you get rid of the 75558, the difference is pretty small. My favorite is the NE5532, then TI's RC4558. The Burr Browns (2134 & 2064 ) are good, but you might not hear the $2.50 more worth of difference. Like Pete said, nothing really sounds bad, just some slightly better to your ears.

The biggest mods you'll hear are the diode mods, the drive mods, and the bass mod. The fidelity mods are more a sum total effect than individual. I'll sit down later, and go through most of what I've done, but this is like only the 3rd nice day we've had this year in cny, so I'm heading out.  

[brrt]

hehe, have a good time and tnx so far for your information!

grt, Brrt

[Jered]

Spending the extra couple bucks for Burr-Brown is well worth it. Not for what you hear, but what you don't, the noise. Those who are hooked on the 4558 hype, I would recommend the 4559.
Jered

[Phorhas]

I suggest to try out CMOS chips...it's well worth the time and testing not only to get a cool tone out of them but also to exercise your ears with differant things.

I tried a CMOS chip (which still lays inside my TS - I can't give you the exact model now, since I'm not at home) and I'm waiting for a TLC2272 to arrive. CMOS give a smoother more "compressed" like sound to my ear and get quite hot in distorion terms...

well... that's to my ears at least...

[Fret Wire]

Spending the extra couple bucks for Burr-Brown is well worth it. Not for what you hear, but what you don't, the noise. Those who are hooked on the 4558 hype, I would recommend the 4559.
Jered

The 4559 is nice, a little more gain and grit, like a RC4558, but more. The Burr Brown's are quiet, but you won't hear any less noise than an NE5532. At least in the TS ckt. There's too many other components in the TS adding to the noise to make the difference between those two chips apparent. You can hear the difference if you go straight from a 4558 to a NE5532 or Burr Brown, however. TI's free samples aside, I'd rather pay .32 for a chip anyday vs. $2.50.  For some reason, the OPA 2134 really does help an SD-1.

As far as the 4558 hype, it started in the commercial (and boutique) pedal market, and that's the only place it's gonna stop. With consumers, not us DIY types. Funny, the 4558 and the 741 were just general "use em' everywhere" duel/single OA's. Because of the 808, the 4558 got seriously hyped. The poor 741 got left behind, it's only claim to pedal fame is that it's an integeral part of the Distortion Plus' sound.

[claydavis]

from the item description:

"You are bidding on an original JRC4558D chip, the common one found in the luscious 1980s Tubescreamer.  This chip is an original 1980s chip, found in home audio equipment. IC is still attached to the board for your inspection.  I have two of these, one is attached to the board, and one has been professionaly removed by me. You are bidding on one chip only. Many believe this is the difference maker between TS-808’s and TS9s. Good luck bidding, questions welcome."

yikes, did you guys see that board? is that an example of his professional removal?

[Rain Dog]

Great thread I read it all, and took notes...

Just out of curiosity. What date range and product type of "80's Japanese" electronics would I most likely find the much hyped JRC4558D?

I'm hoping for an answer like;
These OA's were used by the Fuzzillions from about 197X to 198X and were most often used in things like Panasonic ____'s and Mesobitchy's ______.

Not that I'm going to go out of my way to find them.................. :wink:

-RD-

[cd]

Cheapo clock radios, boom boxes, crap like that.

I really wouldn't bother, to my ears there is absolutely no difference between an '80s JRC and one bought today.  None.  I blind tested two otherwise identical 808 circuit pedals (made 'em myself, matched all the components exactly), only difference being an '80s JRC and a new one (I pulled the '80s one out of a vintage TS-9).  I heard no difference, three other testers heard no difference, one preferred the vintage JRC and another preferred the modern JRC.  Nobody out of the six people testing could pick the vintage chip more than 50% of the time.

[Rain Dog]

Cheapo clock radios, boom boxes, crap like that.

I really wouldn't bother, to my ears there is absolutely no difference between an '80s JRC and one bought today.  None.  I blind tested two otherwise identical 808 circuit pedals (made 'em myself, matched all the components exactly), only difference being an '80s JRC and a new one (I pulled the '80s one out of a vintage TS-9).  I heard no difference, three other testers heard no difference, one preferred the vintage JRC and another preferred the modern JRC.  Nobody out of the six people testing could pick the vintage chip more than 50% of the time.

I can dig that but if I can intercept one on it's way to the scrap heap then I will. Besides the old one will be "broken in"    Yeah, that's the ticket, a broken in, vintage Op Amp.

[dubs]

just to confuse everybody even more ...

check this out http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&category=22669&item=3720182408&rd=1&ssPageName=WDVW

A TS-808 with "even rarer Texas Instruments TL4558P chip" ...

maybe I can get a free sample of the TL4558P from TI?  :lol: [/url]

Actually it's true- TL4558P IS rare. It was made by texas instruments in Japan and no longer in production i.e. no record on TI for samples. Apparently it sounds alot smoother than than the jrc4558D and hence the high market value for these TS.
Damn so overhyped!!

[Tony Forestiere]

Sorry, Echorec...
That isn't quite the JRC4558 all of the clamor is about. The "gennie" has the markings in silver, and the code at the bottom is only four digits. I have at least 10 of yours scavenged from old copier PCBs, But only three of the silver marked ones.
Somebody correct me if I'm wrong

Tony

[petemoore]

I'm sampling some JRC4558's. They sound great.
 Could someone sort out from all this what I should try in an A/B test, if I were to become inclined to do so?
 I have SD-1's, TS's, BluesBreaker, DS-1 [Boss and a Perfed one], also a DIST+ wired for Dual OA.
 Also a Reamer, a Mockman, and a Studip Box, uh...I'm sure I'm missing one. Oh Orange Squeezer...which 'bites' a little bit when I 'clank' a hard attack on a bass string.
 I was thinking of trying a CMOS, but which one?
 I haven't gotten to try a 4559, the one I got didn't seem to work.

[Tony Forestiere]

OOPS! Went to rummage through some old copier PCB's and found three Silver marked JRC4559D's with the four digit code
The day keeps getting better!

Tony

[jimbob]

NO one bought this..I dont know why.. 4.99$ http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50912&item=3812913220 :lol:

thats sarcasm. :wink:

[aron]

I don't know why this keeps coming up. In fact, one of the AMPAGE members wrote to JRC and confirmed that the chips were the same.

If anything, look for germanium diodes or transistors.