the eternal 4558 opamp debate....

[ian87]

i'll begin this post by apologizing in advance. i'm sure this very thing has been posted a hundred times, but...

i'm gonna do another TS9 mod.

Jack Orman says there's no difference b/t the NJM4558 and the JRC4558.
http://www.muzique.com/newsletter.htm

Everyone else seems to think there is, including R.G. Keen.
http://www.geofex.com/Article_Folders/TStech/tsxtech.htm

both of these cats clearly know their stuff, so i am at a loss as to who to believe... i'd like to go with the NJM (cheaper, more readily available) but will happily spend the extra $$ (actually just a few cents) to get the JRC from Small Bear.

thoughts?

-ian

[Ansil]

no offense but i would go with a cmos and forget either one of these.  the cmos one kicks but.. or if you want a smoother type sound get one of these.
http://focus.ti.com/lit/ds/symlink/tlc2262.pdf

look at the schematic of it.   very nice..

[ian87]

no offense taken, ansil -- i'm always open to good info, so thank you!

ok, so i'm looking at the 2262, and that looks promising -- also noticed that Robert Keeley is using a TI chip --  TI RC4558P. i'm gonna be installing a socket, so i may get several and try 'em all out.

now for the newbie question part: what's so great about the CMOS as opposed to the others?

thanks...

-ian

*edit* hey ansil! which of the 2262 series should i be looking at??  :?

[Ansil]

the  tlc2262c  it is the one used in the double drive thread if you can find it.. if you fill out the stuff on the webpage they will let you request samles.. that is what i did. i got the cd coming. ie   the tlc2262cd

cmos opamps are lower operating voltages and it lets them swing rail to rail ie the wave form output has further to go when you have a low voltage chip  .. according to someone who started the debate.  anyway to my ears it is smoother breakup   and fatter tone. just by dropping this in.  of course i can' t  remmeber too much here i don't even have a ts anymore.

but i know i liked what i heard

[Dai H.]

If it's what you really want, just buy them and try them. That way you won't have to wonder or speculate any more. The ones Small Bear sells aren't the old ones, BTW.

JRC4558D For Tube Screamers. Made by the same company, New Japan Radio (NJR), that made the original chips. All reviews indicate they sound identical to the NOS parts in TS clones, and they're MUCH cheaper.

Probably, he calls it "JRC4558" instead of "NJM4558" so it's easier for people to identify.

[Paul Marossy]

If you want to broaden your horizon, you could try these other dual opamps as well:

NE5532, OP275, KA358, LF353, LM1458, NTE928M, NTE858M, RC4558 as well as many others. I haven't personally tried all of these, but I'm sure each one would give a little different flavor since the TS circuit seems to be pretty sensitive to opamp types.

[ian87]

If it's what you really want, just buy them and try them. That way you won't have to wonder or speculate any more. The ones Small Bear sells aren't the old ones, BTW.

JRC4558D For Tube Screamers. Made by the same company, New Japan Radio (NJR), that made the original chips. All reviews indicate they sound identical to the NOS parts in TS clones, and they're MUCH cheaper.

Probably, he calls it "JRC4558" instead of "NJM4558" so it's easier for people to identify.

hey dai, thanks. i've actually ordered that chip from Steve before, and they do have JRC4558D printed right on the chip. who knows what i'll get if i order from Mouser....  :roll:

and thanks again, ansil. i'll check out the 2262c/cd posthaste!

-ian

[Peter Snowberg]

I just picked up some new, New Japan Radio 386s from Mouser and they are marked with a JRC part number. Maybe they changed their markings back?

-Peter

[idlefaction]

steve should do a 'TS experiment pack' with one of each  

[brett]

This might not be what you're wanting to hear, but I think Ansil is right...there are much better options than 4558s out there (whatever brand).

also, with respect to

cmos opamps are lower operating voltages and it lets them swing rail to rail

it's interesting that my favourite TS chip, the NE5332, also is a rail-to-rail chip.  It offers significantly less noise than the 4558s (and TL072).  And it's a smoother style of distortion.

In my opinion, you need to do a blind test of chips to avoid pre-conceptions.  No offence to Small Bear, but his RC4558s scored the lowest of about 10 chips when I did a blind TS-9 clone chip shootout a while back.  Even a TL072, which most people rate as bad, was quieter and had similar distortion characteristics (to my old ears).

Anyway, I suggest you either test a few chips, or, if you want to select a single "winner" without testing, go for either a CMOS chip or an NE5332.  

Have fun!!
(PS when I posted 6 months ago suggesting the NE5332, I was surprised to find that I got posts advising that well-known builders, including Gus Smalley and others, agreed.)

[ian87]

thanks brett (and everyone else) for their input!

i ordered a TLC2262CD, a JRC/NJM4558, the TI RC4558, and i know i have at least one TL071 sitting around. i'll install a socket and let my ears decide. but thanks to everyone for the great advice!!

ian

[R.G.]

I need to update that article. I've been doing this for quite a while, so the articles stay even when I learn new stuff.

Since the article was written, I've tested several of the new NJM4558's, which come marked "JRC4558D", and they are essentially indistinguishable from the older ones, as pulled from old stock Japanese audio equipment.

Add my vote to "there's no difference between the NJM4558 and JRC4558." It's what I've been saying here when the topic comes up, but the article didn't change.

[ian87]

the man has spoken.

thanks, R.G. appreciate your input very much.

i'm modding this one for a friend, so i don't know if he'll want it "true to 808 specs" (whatever THAT means these days) or whether he'll go for another opamp.

i'm with idlefaction. i'd definitely pay for a sampler platter of a half-dozen or so IC's.

[Doug H]

thanks brett (and everyone else) for their input!

i ordered a TLC2262CD, a JRC/NJM4558, the TI RC4558, and i know i have at least one TL071 sitting around. i'll install a socket and let my ears decide. but thanks to everyone for the great advice!!

ian

I have tried the TI 4558 chip and it sounds nice. Has a gainier sound than the JRC chip. I agree with other, try a bunch of different op amps and compare.

Doug

[Dai H.]

If it's what you really want, just buy them and try them. That way you won't have to wonder or speculate any more. The ones Small Bear sells aren't the old ones, BTW.

JRC4558D For Tube Screamers. Made by the same company, New Japan Radio (NJR), that made the original chips. All reviews indicate they sound identical to the NOS parts in TS clones, and they're MUCH cheaper.

Probably, he calls it "JRC4558" instead of "NJM4558" so it's easier for people to identify.

hey dai, thanks. i've actually ordered that chip from Steve before, and they do have JRC4558D printed right on the chip. who knows what i'll get if i order from Mouser....  :roll:

and thanks again, ansil. i'll check out the 2262c/cd posthaste!

-ian

Yes, I know the new ones also have "JRC" marked on them. Look how New Japan Radio Corp. chips are sold here:

http://www2.cyberoz.net/city/satodenk/aic.html

"NJMXXXX", (but the chips themselves have been marked "JRC" all along. I've seen transmitting tubes bearing the "JRC" logo, so apparently it's an old logo they've been using for a long time.  "JRC4558" is more of a tube screamer/guitar player thing. The chips have never been marked "NJM" AFAIK.

The older ones have a shinier, smoother texture to the package, and look like this:



AFAIK, the changeover occured in '90.

Just try a bunch and get it out of your system, lol...

Dai

[Manolo Dudes]

In my opinion, the best sounding modern chip I've tried is the Ti RC4559. Sounds fat and sweet to my ears.

OTOH, I want to try TLC2262 and TLC2272. They look promising.

[analogguru]

The secret lies in one Diode added in newer chips to improve performance.
Use a (even a new) TI 4558 or 4559 and you will get good results, they still don´t use this diode inside.

Good Luck, analogguru

[Chris S]

I moded a ts10 to 808 specs using a LM1458 (it was the only one of various recomended opamps available in my part of Australia). It was a great improvement. Would love to hear what others think of it as I don't have a 808 lying around to do any comparisoms.

Chris

[uncle boko]

I think perhaps that differences perceived between various opamps rely on good hearing, which I'm sure many of the posters here do not have having blasted their ears with distortion!

[Peter Snowberg]

I think perhaps that differences perceived between various opamps rely on good hearing, which I'm sure many of the posters here do not have having blasted their ears with distortion!

That's why I get others to give me feedback about how my stuff sounds.

Tinnitus is a real bummer.

Don't think it can't happen to you. It happened to me.

Hearing Education and Awareness for Rockers
http://www.hearnet.com/

-Peter