1980 Texas Instruments RC4558P vs current TI-RC4558P
- Thread starter JMP/HBE
- Start date
devastone
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
That video illustrates a lot of things, soft clipping vs hard clipping, different diodes, and yes, different opamps, not old vs new 4558, but a wide variety of different opamps in the same circuit.
That video illustrates a lot of things, soft clipping vs hard clipping, different diodes, and yes, different opamps, not old vs new 4558, but a wide variety of different opamps in the same circuit.
PFDarkside
of the Forum
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
I have a tough time hearing the differences between some of the opamps, so I figure I couldn’t hear a difference between old/new of the same component.
JMP/HBE, have you made your swaps and comparisons yet?
I have a tough time hearing the differences between some of the opamps, so I figure I couldn’t hear a difference between old/new of the same component.
JMP/HBE, have you made your swaps and comparisons yet?
devastone
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
The old ones just call you "sonny" a lot and complain about being cold.
The old ones just call you "sonny" a lot and complain about being cold.
JMP/HBE
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
Yes ive mixed & matched. The differences were anywhere from minimal to outstanding. The best ones ive gotten so far are USA Raytheons from early 80's. Ive stocked up on them.
Yes ive mixed & matched. The differences were anywhere from minimal to outstanding. The best ones ive gotten so far are USA Raytheons from early 80's. Ive stocked up on them.
Jacew
New member
devastone
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
You might try some Burr Brown OPA2134s, I know, they aren't 4558s, they are much better spec wise and sound cleaner/more open IME, and their pinouts are the same. Of course, part of the beauty of the 4558 in OD/Dist pedals is the same as the LM308 in Rat circuits, they are actually pretty crappy generic opamps. The 2134s were designed specifically for audio applications so they have less noise and are more transparent, that can be a good thing in most applications, but "cleaner" may or may not be what you are looking for.
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtxdzBvM0rKca1NCdcAPFSCaGg8q6KvJG8=
Specs - http://www.ti.com/lit/ds/symlink/opa2134.pdf
You might try some Burr Brown OPA2134s, I know, they aren't 4558s, they are much better spec wise and sound cleaner/more open IME, and their pinouts are the same. Of course, part of the beauty of the 4558 in OD/Dist pedals is the same as the LM308 in Rat circuits, they are actually pretty crappy generic opamps. The 2134s were designed specifically for audio applications so they have less noise and are more transparent, that can be a good thing in most applications, but "cleaner" may or may not be what you are looking for.
https://www.mouser.com/ProductDetai...=sGAEpiMZZMtxdzBvM0rKca1NCdcAPFSCaGg8q6KvJG8=
Specs - http://www.ti.com/lit/ds/symlink/opa2134.pdf
JMP/HBE
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
I have one, haven't tried it yet. Ive heard mixed reviews but don't know what to expect.
NegativeEase
New member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
IN my experience, the difference in new and old chips is the same as variation between new chip lots, or between the old chip lots.
Every chip new and old is just slightly different but not enough to even concern yourself, except an occasional actual bad one.
IN my experience, the difference in new and old chips is the same as variation between new chip lots, or between the old chip lots.
Every chip new and old is just slightly different but not enough to even concern yourself, except an occasional actual bad one.
Artie
Peaveyologist
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
I think that it was Jack Orman who had an article about this, but I've been searching his webpage and can't locate it. To paraphrase, he basically said that to worry about the sonic characteristics of an op amp, when used in an OD/Distortion pedal, where the primary purpose is to cause extreme distortion, is a bit of silliness. (He said it better.)
I think that it was Jack Orman who had an article about this, but I've been searching his webpage and can't locate it. To paraphrase, he basically said that to worry about the sonic characteristics of an op amp, when used in an OD/Distortion pedal, where the primary purpose is to cause extreme distortion, is a bit of silliness. (He said it better.)
JMP/HBE
Well-known member
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
Im not after a change in "distortion". Some of these chips have a sweeter midrange than others.
Vasshu the humanoid typhoon
Unseen
Re: 1980 Texas Instruments RC4558P vs current TI-RC4558P
.....it is a game with no rewards worth the effort....but have fun...
.....it is a game with no rewards worth the effort....but have fun...
