the eternal 4558 opamp debate....

[Aharon]

I know my opinion doesn't count for much and maybe I misunderstood but I find differences between the 4558s(maybe not the particular suffixes that were mentioned above) but some of them are night and day.
Also I'd like to add that Brett is right about the 5532,since I tried one I haven't removed it from my TS,definitely different and smooth.
Aharon

[Jay Doyle]

it's interesting that my favourite TS chip, the NE5332, also is a rail-to-rail chip.  

Brett, according to the Fairchild datasheet with a supply of +/-15V the output can only swing to +/- 13V with a worst case of +/- 12V.

It is not a rail to rail, though I do think that it sounds good.

My favorite is the LF412 though Doug H has said that he didn't hear much of a difference, I think the bass is a bit better defined.

Above an idea was to build a discrete opamp version of the TS. I have done this, it sounds good and is workable and has a different feel, but without adding CCS loads and special biasing (both of which would jack the parts count up in a big way, which it already is using discrete opamps) there isn't enough gain there to reach normal TS distortion levels. Using a MOSFET in/BJT out discrete opamp gets you close but probably on about 75% of the gain. I do like discrete opamps though, a lot can be done with them.

Jay Doyle

[Ansil]

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!

speak up.. no need in whispering!!!!!

[Ansil]

try a lm386  you need to mod it but it will work

[Ansil]

http://www.geocities.com/austenfantanio/ts92386.htm

thats the link for the ts9 to lm 386 mod  there is another one that i have done only once that used two lm386's to utilitze both halves of an opamp..  fattt and heavvyy

[ambusch]

i just was trying all the ones i had on hand and i thought the op2604AP "burr brown" chip sounded the best to me out of jrc 4558D, rc 4558p, rc 4559?, tl072, and an njm 2043 D.  all though one of my tube screamers is hand made and completely modded out with pre-bass, post-bass, fuzz(on/off and character), and od( on/off and character) modes as well as a boost. and the other tube screamer is a silver mod from analog man which also has a post-bass switch and a few of my own modifications.  so my opinion may be of no use, however i felt that this chip was the most smooth and dynamic in all frequencies.  Not quite as trebly i feel as the jrc 4558D, but really full sounding.  Anyway thats the chip i dig, unfortunately its the most expensive.

[QSQCaito]

OMG, apprecitae opinions, but it was a 2003 thread :p I believe they have finishde their TS, if they stillin the forum

bye

DAC

[ambusch]

OMG, apprecitae opinions, but it was a 2003 thread :p I believe they have finishde their TS, if they stillin the forum

bye

DAC

I know i know... but this thread seemed like it wasn't just for one particular builder.  I mean i come and search the forum for ideas lots of time and read what other people post about topics that were from a long time ago.  New input on an old topic didn't seem like that ridiculous at the time anyway.

[StephenGiles]

SSM2135, NJM2114, NJM2122, NJM2100, LM1458 the list is endless for good sounding duals at dawn!

[Sir H C]

Several things here:

1.  Variances in parameters for particular op-amps are very wide.  50% for many parameters.  So getting to say that all NJR or JRC op-amps sound the "same" is going to be a stretch.

2.  I would have to guess that most of these ICs have been ported to other processes since they were first put out there.  Usually a shrink to make the die size smaller or porting to get rid of the older, less useful processes.  This will be a difference between the same "chip".

3.  So long as you meet or beat the specs, you can create the internal circuitry completely different when creating a second source IC.  One might even have CMOS in there because they have it.  This can make them sound totally different.

4.  Sometimes they "lose" the recipe for the process.  Another time that things just will always be different.

To really compare, you would probably be best off decapping the ICs and see how similar the die are to each other.  This is not a trival task as you need some pretty strong acid to delid the devices, then you have to look under a good microscope.  Possible to do.

[R.G.]

And the ultimate weapon is still an IC socket.

[Sir H C]

A good one with machined pins.

[brett]

What about DUAL IC sockets for DUAL DUAL op-amps?

One in a Tubescreamer and one in a BluesBreaker?   

ok...that was being silly...