JRC-4558 Op Amps - I have a few
Geoff Howse
amps. Anyone in Australia want to buy? (Sorry not sending stuff O/S)
Part payment could include modifying my plastic TS5 to TS808 specs.
Replies to gho...@selcon.com.au
Geoff
Lord Valve
Lord Valve Speaketh:
The 4558 chip is one of the most common on the planet. You can
buy 'em damn near anywhere for less than a dollar each. Is
there a 4558 famine in Oz or something? I have several hundred
in stock.
Lord Valve
VISIT MY WEBSITE: http://www.freeyellow.com/members2/lord-valve/
Good tube FAQ for newbies. Click the e-mail link and join my
SPAM LIST; just put "SPAM ME" in the header and I'll sign you
up. (If you only want a set of e-mail catalogs, put "CATS ONLY"
in the header.) I specialize in top quality HAND-SELECTED NOS and
current-production vacuum tubes for guitar and bass amps. Good
prices, fast service. TONS of gear and parts in stock...let's DEAL!
NBS Electronics, 230 South Broadway, Denver, CO 80209-1510
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Jonathan Krogh
in the Tubescreamer, i read somewhere that later revisions dont go in as
well, I have heard of guys scrounging old dead gear for these things for the
TS application, but its gotta be pre '83 gear, otherwise better buy new off
the shelf.
Lord Valve wrote in message <7l2u4c$5...@dfw-ixnews14.ix.netcom.com>...
Tiny Tubes
TT
Jonathan Krogh <j-gk...@carib-link.net> wrote in message
news:7l3bir$bq2$1...@news.carib-link.net...
ViNtAgE SoLiD StAtE
solid state... ;-)
Tiny Tubes <dbo...@bellsouth.net> wrote in message
news:Tqjd3.3669$eF4...@news2.atl...
Tonefactor
>solid state... ;-)
RG Keen, among others, already stocks this kind of stuff. You can order the
original JRC4558D's from him for $5 a piece.
LarrySB
>The 4558 chip is one of the most common on the planet. You can
>buy 'em damn near anywhere for less than a dollar each. Is
>there a 4558 famine in Oz or something? I have several hundred
>in stock.
Yeah the 4558 is a common as hell industry standard dual opamp, and there's
probably 3 dozen other part numbers that will drop right into the same holes
and work.
By lucky accident, the original TS808 and TS-9 TubeScreamers happened to use a
version of this chip which works better when run with a diode clipping feedback
loop.
The parameter in question is "no latchup".
Some versions of 4558 latchup when pushed near clipping, others do not. The
original JRC4558D did not.
When Ibanez reissued the TS9, they are exact duplicates of the originals, right
down to the PCB foil pattern.
What's different?
The chip. Some versions got chips which sound kind of harsh rather than the
soft warm distortion that the TubeScreamer was known for.
Given that Stevie Ray Vaughan and many others used these old TubeScreamers
gives them quite a demand in the used (dare I say "vintage") market. Original
TS808's got for well over $300 now.
Happily, the reissue TS9 is easily tweeked by replacing the IC. There are other
chips known to have the desirable distortion sound, the RC4558 ( common in
modern Peavy stuff) which I think is made by TI sounds good.
The NJM4559 sounds bad. NJM is what JRC became when the company changed names.
You can read all about it on RG Keen's effects pages at
http://www.eden.com/~keen .
I'm looking for a verifiable pre 1983 JRC4558D so I can do a taste test of my
own. I have a TS9 Re Issue equipped with an IC socket so I can try various
chips in it.
Depsite the fact that these chips were produced in the millions and millions,
and found in everything from musical isntruments to toys to cheapo japanese
HiFi, I have had a bit of trouble locating something to rob one from that I can
*verify* was pre-1983.
If anyone has something that can be verified as a pre-1983 produced JRC4558,
I'd like to have it.
I'm sure there's an old Peavy backstage or Crate that's dead from that time
frame in someone's attic or garage or shop.
--
Dr. Nuketopia
The Blue Glow FAQ is temporarily down - look for a new link in the near future.
When replying, please note that your email is *not* spam in the subject line.
Geoff Howse
before '83.
GH
Tiny Tubes <dbo...@bellsouth.net> wrote in message
news:Tqjd3.3669$eF4...@news2.atl...
> Christ, Vintage solid state.
> TT
> Jonathan Krogh <j-gk...@carib-link.net> wrote in message
> news:7l3bir$bq2$1...@news.carib-link.net...
> > I think the real super mojo JRC4558D versions are the pre 1983 ones as
> used
> > in the Tubescreamer, i read somewhere that later revisions dont go in as
> > well, I have heard of guys scrounging old dead gear for these things for
> the
> > TS application, but its gotta be pre '83 gear, otherwise better buy new
> off
> > the shelf.
> >
> >
> >
> > Lord Valve wrote in message <7l2u4c$5...@dfw-ixnews14.ix.netcom.com>...
> > >In <7l27sl$3ho$1...@news.mel.aone.net.au> "Geoff Howse"
> > ><gho...@selcon.com.au> writes:
> > >>
> > >>Just opened up my Casio CZ-5000 synth and found it has about 4
> > >JRC-4558 op
> > >>amps. Anyone in Australia want to buy? (Sorry not sending stuff O/S)
> > >>
> > >>Part payment could include modifying my plastic TS5 to TS808 specs.
> > >>
> > >>Replies to gho...@selcon.com.au
> > >>
> > >>Geoff
> > >
> > >
> > >Lord Valve Speaketh:
> > >The 4558 chip is one of the most common on the planet. You can
> > >buy 'em damn near anywhere for less than a dollar each. Is
> > >there a 4558 famine in Oz or something? I have several hundred
> > >in stock.
> > >
DrFuzz
.>I'm not sure when the Casio CZ5000 came out, but I'd guess it was well
>before '83.
>
You might guess that, but you would be wrong. 1985 or so at the earliest
Tonefactor
>own.
I have a TS-808 that I bought new in 1980. I've compared it side by side with
my reissue TS-9 which has been converted to 808 specs including a JRC4558D
which I bought for $5 from RG Keen. There is absolutely no difference in sound
between the two.
Lord Valve
lar...@aol.comNOspahm (LarrySB) writes:
(snip)
>If anyone has something that can be verified as a pre-1983 produced
JRC4558,
>I'd like to have it.
Don't they have date codes on 'em? Damn near every IC I've seen
does...
LV
J Orman
>
>Some versions of 4558 latchup when pushed near clipping, others do not. The
>original JRC4558D did not.
You can read about the theory of latchup in IC chips when used in clipping
circuits, and a simple modification at:
http://www.muzique.com/amz/latch.htm
****** best regards, JACK *******
***** Visit the ANALOG MUSIC ZONE *****
* Schematics * Information and music related files *
http://www.muzique.com/amz/index.html
x-no-archive: yes
LarrySB
>does...
>
>LV
Here's the wackiest part: JRC didn't start putting date codes on them until
later. The "mojo" ones have no date codes appearantly.
ssm
[etc.]
>I'm looking for a verifiable pre 1983 JRC4558D
[etc.]
Have you cruised the thrift shops for older radios, stereos, etc.?
There's an independent electronics store I often visit for ICs. I picked up
some 4558's there once and built 'em into a preamp. Couple years later I
read up on the scientific theories behind all the TS808 and 4558 voodoo and
just for kicks I opened up that preamp. The chips read "JRC4558D."
Nowadays, one of those JRCs lives in my el-cheapo TS-5 plastic potato bug
tubescreamer. It sounds pretty good, but is it the genuine holy grail of
tubescreamer chips? Beats me.
Good luck in your search!
LarrySB
>>I'm looking for a verifiable pre 1983 JRC4558D
>[etc.]
>
>Have you cruised the thrift shops for older radios, stereos, etc.?
Yeah but wouldn't you know it, lots of old junk either after 1983 or lacking in
the needed part. They are out there somewhere. JRC probably made a bazillion
give or take a few hundred million of those.
je...@nospamop.net
Shinal) wrote:
> I'd like to know just how much of a difference there is in the
>D series and DX series JRC 4558's.
Watching this discussion brings Nigel Tufnel to mind.
P.S. Make sure to match your geraniums.
LarrySB
>with the need to know, just curious what the difference in these
>otherwise incredibly similar chips is. I'm a minutiaeophile.
RG Keen covers it pretty well on his web pages on the tubescreamer, but I'll
give it a quick stab.
An opamp like the 4558 is kind of black box. Power goes in, signal goes in,
signal comes out. It has spec's for current draw, noise, slew rate, bandwidth,
input and output impedance and so on. As long as the chip meets those specs it
is ok.
All chipmakers continuously refine their manufacturing process and designs.
When they can die-shrink a part and get more units per wafer, the cost goes
down per unit. Usually the part gets better from an spec standpoint too,
drawing less current making less noise having better bandwidth and so on.
How it sounds in guitar distortion box ain't part of the equation.
Just by luck, the JRC4558 is a chip that sounds "good" in that application.
There are other parts that sound good too, like the RC4558 which I think comes
from TI.
It would appear that the parameter that makes it sound good is "no-latchup"
operation. Opamps are used in feedback amplifier operations. They have two
inputs and the opamp will try to keep the inputs as close together as possible
as determined by the feedback loop. When the signal approaches the plus or
minus rail near clipping, some opamps "latch-up" and blat out, others suddenly
reverse polarity and others handle the situation more gracefully.
Some opamps are specified as no "latchup operation." Others are unspecified and
might or might not, depending on the particular design of the chip. Chips from
different companies may have radically different internal circuits. Even chips
from the same company with the same part number may have very different
internals depending on production run.
What exactly is on the wafer is anyone's guess. Probably someone at New
Japan/JRC knows or knew and never considered it consequential.
J Orman
>minus rail near clipping, some opamps "latch-up" and blat out, others
>suddenly
>reverse polarity and others handle the situation more gracefully.
>
>Some opamps are specified as no "latchup operation." Others are unspecified
>and
>might or might not, depending on the particular design of the chip.
I dare say that i was the first person to use the phrase "latch-up" in
conjunction with the clipping glitches associated with opamp distortion units
in my article about TS opamps at http://www.muzique.com/amz/latch.htm
Previously the term was associated with transistor power amp output stages.
Latch-up is a type of distortion produced when a transistor is driven into
saturation, and the saturated transistor "hangs" in the ON state before slewing
in the opposite direction. This is different than the previously oft-quoted
theories that slew-limiting, drive limitations or phase reversal are the source
of the opamp non-linearities.
In reality, it may be a combination of some of the above, or some other
explanation entirely; it's not been proven with certainty. I've never seen a
spec for "latch-up" associated with an opamp unless it is under some name that
I'm not equating with that.
The difference in sound is extremely subtle. It may be only a db or less in
certain critical frequency ranges, but can be heard by discriminating
listeners. Most of the time one of the "recommended" opamps for TS-type
circuits will give excellent performance, especially some of the newer designs.
The ear should be the final judge, as in all cases with music.
ALAN THOMPSON
like to mention something. I have recently been using the Vox Valvetone pedal in
place of my TS9 RI, and it seems to be gaining popularity. Just for the heck of
it, I popped it open the other day, and guess what? JRC4558! So how come Ibanez
can't supply this opamp in their reissues? Everybody is getting their TS's modded
to 4558, it was pretty stupid of Ibanez to put that lousy opamp in the pedals.
A.T.
Lord Valve
<Zomb...@worldnet.att.net> writes:
>
>Since the discussion of JRC4558's is usually in regard to the Tube
Screamer, i'd
>like to mention something. I have recently been using the Vox
Valvetone pedal in
>place of my TS9 RI, and it seems to be gaining popularity. Just for
the heck of
>it, I popped it open the other day, and guess what? JRC4558! So how
come Ibanez
>can't supply this opamp in their reissues? Everybody is getting their
TS's modded
>to 4558, it was pretty stupid of Ibanez to put that lousy opamp in the
pedals.
>
>A.T.
>
Try a 1458 in your TubeScreamer. You may be surprised.
Lord Valve
VISIT MY WEBSITE: http://www.freeyellow.com/members2/lord-valve/
Good tube FAQ for newbies. Click the e-mail link and join my
SPAM LIST; just put "SPAM ME" in the header and I'll sign you
up. (If you only want a set of e-mail catalogs, put "CATS ONLY"
in the header.) I specialize in top quality HAND-SELECTED NOS and
current-production vacuum tubes for guitar and bass amps. Good
prices, fast service. TONS of gear and parts in stock...let's DEAL!
NBS Electronics, 230 South Broadway, Denver, CO 80209-1510
Phone orders/tech support after 1:00 PM Denver time at 303-778-1156
NOW ACCEPTING VISA AND MASTERCARD
CHAT WITH LORD VALVE: Log onto any DALnet server and join
channel #CONELRAD. Look for me there most any night after
11:00 PM Denver (Mountain) time. Guitar-amp questions and
what-have-you are welcome.
"I got the chop...I'll never get popped." - Tower of Power
Jack D. Wills
J Orman <jor...@aol.comNOSPAM> wrote:
>I dare say that i was the first person to use the phrase "latch-up" in
>conjunction with the clipping glitches associated with opamp distortion units
>in my article about TS opamps at http://www.muzique.com/amz/latch.htm
>Previously the term was associated with transistor power amp output stages.
>
I dare say "maybe not". Take a look at "IC Op-Amp Cookbook" First
Edition, by Walter G. Jung, copyright 1974. Pages 128-130 are a
section devoted to "latch-up" in op amp input stages. A variety of
cures are also shown.
This edition is long out of print. It was Sams #20969. I don't know
if the third edition (which is currently in print) still contains this
material.
Jack Wills
--
Dr. Jack Wills
Teknetics
430A South Venice Blvd.
Bob Sweet
I think he was talking about in reference to a Ts-9, or distortion
effects in general. How did you get that it was the first time anyone in
the world ever brought up that term. That term has been around since the
begining of electronics, and I'm sure Mr. Orman knows that.
--
Bob Sweet
Sweet Sound Electronics, Inc.
http://www.sweetsound.com
Jonathan Krogh
ALAN THOMPSON wrote in message <377B218F...@worldnet.att.net>...
>Since the discussion of JRC4558's is usually in regard to the Tube
Screamer, i'd
>like to mention something. I have recently been using the Vox Valvetone
pedal in
>place of my TS9 RI, and it seems to be gaining popularity. Just for the
heck of
>it, I popped it open the other day, and guess what? JRC4558! So how come
Ibanez
>can't supply this opamp in their reissues? Everybody is getting their TS's
modded
>to 4558, it was pretty stupid of Ibanez to put that lousy opamp in the
pedals.
>
>A.T.
>
>
>
'pre 1983' ones that are worth the effort,
So, the later ones might as well be swapped for whatever
Troy McClure
Zomb...@worldnet.att.net wrote:
>Everybody is getting their TS's modded
> to 4558, it was pretty stupid of Ibanez to put that lousy opamp in
the pedals.
>
> A.T.
I don't know if it was stupid or a strategic position(the old either
complete moron or utter genious thing). On one hand, if they released
a "TS-808 reissue" and it sucked as bad as the stock TS9 reissues,
customers would be majorly ticked. With this situation, the customer
gets a box that with some very minor mods and the right chip, is
virtually identical to the original. Ibanez doesn't need to secure new
production of the chip and customers have an upgrade path.
Everybody's happy, but what about Ibanez' claim about the TS9 "And what
the original TS9 was, the 'reissue' TS9 is...same parts, sane circuitry
[sic] and metal housing, same seasick green paint, same factory, and
the 'new' TS9's actually built by many of the same people who built the
'old' TS9's (compare that to other so-called 'reissues')."
Would anybody consider this false advertising?
--
Matt Warren
http://www.jps.net/matt7591
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
LarrySB
>I dare say that i was the first person to use the phrase "latch-up" in
I've seen this in various IC data books over the years.
>I've never seen a
>spec for "latch-up" associated with an opamp unless it is under some name
>that
>I'm not equating with that.
http://www.ti.com/sc/docs/products/analog/tl072.html
Look in the middle of the page under "Features"
"Latch-Up-Free Operation"
J Orman
>
>I've seen this in various IC data books over the years.
The entire sentence that you are quoting says: "I dare say that i was the first
person to use the phrase latch-up in
conjunction with the clipping glitches associated with opamp distortion units".
Certainly the phrase "latch-up" has been used before as I state in the
article.
>http://www.ti.com/sc/docs/products/analog/tl072.html
Interesting. However I downloaded the spec sheets and the other white papers
listed on that page and none have any mention of what they mean by "latch-up
free operation". I would be interested in their exact meaning of this and will
keep looking through their app notes. I'll post if I find anything.
The best explanations of the "latch-up" or "hang-up" subject that I have seen
are in a couple of books by John Lindsey Hood, which is the reference that gave
me the idea to pursue this topic in relation to fuzz boxes. (His books are
excellent BTW).
Andrew McWhirter
>
> Try a 1458 in your TubeScreamer. You may be surprised.
Yeah, I'd agree with that. My homebrew TS copy was initially completed
with a LM1458 (National Semi I think) and I later found a place that had
genuine JRC4558's for a couple of bucks, so I bought one. I couldn't hear
much difference. No idea of the vintage of the JRC chip, though.
Cheers
Andrew
--
The return address will work as is...
These opinions are hereby disowned by the company I work for.
LarrySB
>The entire sentence that you are quoting says: "I dare say that i was the
>first
>person to use the phrase latch-up in
>conjunction with the clipping glitches associated with opamp distortion
>units".
> Certainly the phrase "latch-up" has been used before as I state in the
>article.
Ok fair enough. I perhaps misinterpreted what you meant. I guess what you are
saying is that you figured out that latch-up might be the root cause of the
rougher sound from some fuzzboxes. In that case, my hat is off for you, because
I read about it on your page and RG Keens pages.
Tip to the rest of you guys: Jack's webpages are excellent as are Keen's.
Well worth bookmarking!!!
I was responding more to the part where you'd not seen it listed in any spec
sheets, and I gave an example where the exact term was used in a data sheet.
Like you say though, there's nothing in the data sheet to explain what TI means
by the term. I'd just assumed what it meant, as I've heard the term explained
in one of a few opamp books I read long ago in a galaxy far far away.
Cheers,
Miles O'Neal
> Would anybody consider this false advertising?
I'm sure plenty of lawyers would. Especially
the ones who specialize in class action lawsuits
over trivial things.
I just consider it marketing hype. (IE, garbage.)
I never believe marketing hype.
-Miles
ssm
>Since the discussion of JRC4558's is usually in regard to the Tube
Screamer, i'd
>like to mention something. I have recently been using the Vox Valvetone
pedal in
>place of my TS9 RI, and it seems to be gaining popularity. Just for the
heck of
>it, I popped it open the other day, and guess what? JRC4558! So how come
Ibanez
modded
>to 4558, it was pretty stupid of Ibanez to put that lousy opamp in the
pedals.
>
>A.T.
Just having the "JRC4558" stamped on the IC doesn't always mean it's the
desireable chip. It could be one of the horrible, more recent production
models. Even so, it does seem odd that Ibanez would release product with
lousy sounding components. I would guess that they don't place as much
importance on that product line as many of us do.
Is that Valvetone a good unit? I'll have to try one sometime. Fill the
world with sound!
Sterling
jc maillet
good point, I went through a whole bunch of op-amps when cloning and
tweaking the tube screamer and found the TL072 as having near identical
clipping characteristics as the good old JRC4558 ... seems like the
op-amp's output current slewing would dominate in this respect, all else
being pretty much the same ... try it out, the TL072 is no joke in this
circuit ...
jc www.lynx.bc.ca/~jc
> Sterling
Ron Bales
>good point, I went through a whole bunch of op-amps when cloning and
>tweaking the tube screamer and found the TL072 as having near identical
>clipping characteristics as the good old JRC4558 ... seems like the
>op-amp's output current slewing would dominate in this respect, all else
>being pretty much the same ... try it out, the TL072 is no joke in this
>circuit ...
Are there really no better chips for this job? Has anyone worked his
way through all the more modern versions of these. I'll believe you
if you say, but wow. Whoda thunk we'd be looking for vintage chips.
ROn
claude beaupre
For a totally different flavor, LF353N has a very musical brown tone.
Warning, sounds poor with weak battery.
Claude
Ron Bales a écrit dans le message <3782d801...@news.gte.net>...
ALAN THOMPSON
overdriven AC30. It's true bypass, and cheap (I got mine for $50 when GC had a
special on them). It's made in China, so I had my reservations, and I also
hated the Vox Tone Bender reissue, but the Valvetone turned out to be cool.
Construction seems to be as good as other stock pedals on the market, time will
tell about reliability.
A.T.
ssm wrote:
> ALAN THOMPSON wrote in message <377B218F...@worldnet.att.net>...
> >Since the discussion of JRC4558's is usually in regard to the Tube
> Screamer, i'd
> >like to mention something. I have recently been using the Vox Valvetone
> pedal in
> >place of my TS9 RI, and it seems to be gaining popularity. Just for the
> heck of
> >it, I popped it open the other day, and guess what? JRC4558! So how come
> Ibanez
> >can't supply this opamp in their reissues? Everybody is getting their TS's
> modded
> >to 4558, it was pretty stupid of Ibanez to put that lousy opamp in the
> pedals.
> >
> >A.T.
>
> Just having the "JRC4558" stamped on the IC doesn't always mean it's the
> desireable chip. It could be one of the horrible, more recent production
> models. Even so, it does seem odd that Ibanez would release product with
> lousy sounding components. I would guess that they don't place as much
> importance on that product line as many of us do.
>
> Is that Valvetone a good unit? I'll have to try one sometime. Fill the
> world with sound!
>
> Sterling