Op Amps

The lists below show which op amps are pin-compatible with other op amps.  All op amps listed in each group are pin-compatible.  There are many more op amps, but these are ones we have in stock at the time of writing.  If you don't see one you're interested in, let us know and we'll check availability.

There are some groups that have slightly different pin-outs than other groups.  Depending on the circuit, those groups may also be pin-compatible.  Those relationships are noted as "Possible compatible groups".

Op amps are widely counterfeited, especially the expensive ones.  Even inexpensive ones are faked regularly.  We source from reliable distributors for current production models.  Many vintage or uncommon out of production models require us to buy from secondary sources.  We screen for fakes and counterfeits, but some are difficult to detect.  There is a possibility that we could be fooled occasionally, so we cannot absolutely guarantee every model.  This should very rarely be an issue, but there are so many fakes available and they are so widespread that they can find their way even through normally reliable vendors.

Op Amp Properties

Just like tubes, transistors, and other audio circuit components, particular op amps are often singled out as superior in some way or another.  You may see comments about their "bandwidth", "slew rate", "total harmonic distortion (THD)", or "noise level".  You may also see comments that some are "more hi fi", "warmer", "noisier", "lo fi", or some other descriptive term.  Are these comments real?  Do they need to be considered?  Or is this more "mojo talk"?  Fair questions, but the answers aren't always clear.

Op amps have been in production for decades, and are still in production with new and improved models today.  As a result, if you look at datasheets, you'll find widely varying levels of detail and specs, with older models often having less of the information that might be useful.  Unless you get into highly technical analysis, there are only a few specs that might be useful on their own.  Bandwidth is one that could be useful, but rarely is.  The reason is that our ears can only hear from about 20Hz to 20KHz, and our ears generally aren't particularly "hi fi" devices.  Virtually every op amp ever designed has far more bandwidth than is necessary for human audio, often several orders of magnitude more than is necessary.  

Slew rate is another sometimes-used spec for selecting op amps.  You can think of slew rate as how responsive the op amp is to changes in the incoming signal.  Higher slew rates would allow them to react quickly, giving you a more accurate processing of the input signal.  Op amps do have a variety of slew rates.  Some of the older ones were quite slow, relative to newer designs.  Good ears may well be able to detect the lower slew rates, typically described as "lo fi".  Some older op amp circuits used those older op amps, of course.  They may be important to the overall tone of the circuit.  "Critical" to the sound, or just "important"?  That's difficult to say, because those older circuits also used other older components that might also contribute significantly to the resulting sound.  If you swap the slow op amp out for a faster one, you may hear the difference if you are listening for it.  But if you take a newer circuit already using a faster op amp and swap it for another fast op amp, it is much less likely you'll be able to hear a difference.  It is probably only a small number of older, slower op amps that are slow enough that swapping an op amp is going to make much difference you can hear.

OK, how about THD and noise levels?  These can vary by several orders of magnitude from older, noisier designs to newer "hi fi" low-noise designs.  But noise filtering and other frequency manipulation in a circuit can hide those differences.  It is also the case that "noise" isn't all alike, and an absence of noise doesn't always sound better to everyone.  This can become a matter of taste or preference.  But it can be heard, particularly between those that are at the quiet end of the range vs those at the noisy end of the range.  The difference can become more apparent in high gain circuits, like distortions and fuzzes.  Even tiny amounts of noise "gained up" a few orders of magnitude can be very noticeable.  That may be an instance where you would want to consider a low-noise op amp.  In most cases, the designer probably already has, but perhaps a newer op amp would be quieter than what was available at that time, giving you a better, cleaner sound when cranked up.

You may see some op amp described as "more hi fi", meaning a flatter, truer response across audio frequencies, providing no coloration of the input signal.  Or maybe you'll see some op amp, perhaps the famous 4558 varieties, described as "warm".  Op amps are generally not meant to provide audio "coloration" of their tone.  Most aren't even really designed specifically for audio at all, although they work great for it.  Generally, you have to be careful here.  It is much more likely that warmth, darkness, brightness, or other descriptions of the resulting frequency content is caused by other parts of the effect circuit, not primarily or even at all, by the op amp.  For example, that famous 4558 op amp family was used in the Tubescreamer, a circuit designed specifically to shift the tone of the signal.  A Tubescreamer is going to sound pretty much like a Tubescreamer, no matter which op amp you choose, unless there are other mods to the circuit.  Believing a 4558 op amp is going to make any circuit have some of the same properties of a Tubescreamer circuit is simply incorrect in general.

How about vintage parts vs new production?  Sticking with the famous 4558 family of op amps, as an example, you will find that they have been in production for decades and still are.  There are different brands.  Even within single brands, they have been made at different factories, perhaps using different tooling and technologies.  There are some strongly held beliefs that only 4558 op amps made at certain times in certain factories sound "right".  It's doubtful that many, if any, could tell the difference between a variety of 4558's in a blind test, using the same exact circuit.  But maybe.  It's much more likely they have heard those different versions in different circuits, where slight variations in capacitors, resistors, power, guitar, pickups, playing, amps, or other components and factors would make more of an audible difference than the op amp version.

Op amps sort of replaced transistors which sort of replaced tubes.  Sometimes you'll see an op amp or transistor being described as more "tube like".  If you like tube tone, that may be a consideration, but is it real?  Actually, it can be.  There are some characteristics of tube tone that may be present in transistors or op amps.  These aren't necessarily "designed-in" characteristics, and there are no specs for them.  Usually these op amps and transistors divide in this way along underlying technology.  JFET and MOSFET transistors and op amps have some characteristics of tube tone.  We're getting close to the mystic mojo discussions, but there is some technical truth in there.  Harmonics and slightly asymmetric clipping/distortion can be detected, and can sound more "tube-like" than other base technologies.  It is real enough that not only good effects designers, but even solid-state amp designers will often turn to JFET or MOSFET components to capture some of the essence of tube tone without the downside of using tubes.  Changing to a JFET or MOSFET based op amp can make that little bit of difference that changes "meh" to "gotta have it".  It still depends on the circuit and what else is going on besides the op amp in shaping the final tone, but this is one thing that will often come through.  It won't wildly change the tone, but it can be significantly different.

Another very real problem worth considering is counterfeits.  If there is demand for something, someone will make counterfeits.  This happens all the time with op amps, vintage ones, uncommon ones, or new hi-performance ones.  Even dirt-cheap common ones are often fakes made from seconds or rejects.  Sometimes you can tell just from appearance that an op amp is fake or counterfeit.  But it can be very difficult to tell the legit from the bogus.  Even reliable distributors and dealers can be fooled into selling some bogus parts.  Of course, this is particularly true for out-of-production parts where sources aren't likely to be direct-from-manufacturer dealers.  It's difficult to know the provenance.  Even packing materials and labeling can be faked.  Good, current production op amps often sell in the rough range of around 20 - 40 cents each.  Vintage or modern high-end op amps can easily run $5 or considerably higher.  Unless you are buying from a reputable direct dealer, you'll more likely end up with a fake than a real op amp, often with a suspiciously good price for a suspiciously bad reason.  As a result, we rarely stock "vintage mojo" op amps - too many shenanigans.

So what is the net of all this discussion about properties of op amps?  Of course, the ultimate answer is the one your ears give you.  But that isn't always an option before you make a purchase, whether it is a GT rack module, a new pedal, or a used vintage pedal.  When it comes to op amps, we generally try to keep it simple.  If you like the sound of the original effect, stick with the original op amp, without worrying much about whether it was made in the Extra Mojo Plant from the original dies.  If you want to change up the original tone, then consider an op amp swap as an option.  Much of the time, there is no charge to change to a similar but different op amp.  But other options we offer for each module will often give you more of a change up than just switching op amps.  If you play high gain or just don't like analog noise, then a "better" low-noise op amp may yield better results.  Of if you like some essence of tube tone, try a JFET or MOSFET op amp.  We use sockets to hold the ICs in GT modules, including op amps.  That means that it is possible to swap op amps later if you want to do so.  It is usually pretty easy to swap op amps if you know what you're doing and are careful not to damage them or the circuit.

A little "cork-sniffing" with op amps is easy, inexpensive, and may give you great results.  But consider Randy Rhoads used one of the crappiest distortion pedals with one of the crappiest op amps and had great tone.  Prince was also apparently none too picky about his effect quality, but also sounded great.  Don't expect tweaking at this level to have a huge effect - maybe "just enough to matter".  Maybe.

 


SIL-7 Single Op Amps

 

 

7136

1 FREQ COMP
2 +IN
3 -IN
4 -V
5 VOLT COMP
6 OUT
7 V+

 

Possible Compatible Groups

  • none

Members

  • TA7136AP
  • TA7136P

 


SPIL-8 Single Op Amps

 

 

1457

1 OUT
  no pin
2 NC
3 COMP
4 -V
5 COMP
6 +IN
7 -IN
8 V+

 

Possible Compatible Groups

  • none

Members

  • HA1457W

 

 


SIL-8 Single Op Amps

 

 

 

4560L

1 OUT 1
2 -IN 1
3 +IN 1
4 -V
5 +IN 2
6 - IN 2
7 OUT 2
8 V+

 

Possible Compatible Groups

  • none

Members

  • NJM4560L
  • NJM4580L

 

 

5218L

1 OUT 1
2 -IN 1
3 +IN 1
4 -V
5 +IN 2
6 - IN 2
7 OUT 2
8 V+

 

Possible Compatible Groups

  • 4560L

Members

  • M5218L

 

 


SIL-9 Single Op Amps

 

6110

1 +IN
2 -IN
3 BIAS IN
4 CONTROL IN
5 -V
6 VCA OUT
7 BUFFER IN
8 BUFFER OUT
9 V+

 

Possible Compatible Groups

  • none

Members

  • BA6110

 

 

 

4558S

1 V+
2 OUT 1
3 -IN 1
4 +IN 1
5 -V
6 +IN 2
7 -IN 2
8 OUT2
9 V+

 

Possible Compatible Groups

  • 718

Members

  • KA4558S

 

 

 

718

1 V+
2 OUT 1
3 -IN 1
4 +IN 1
5 -V
6 +IN 2
7 -IN 2
8 OUT2
9 V+

Possible Compatible Groups

  • 4558S

Members

  • BA718

 

 


DIP-8 Single Op Amps

 

 

308

1 COMP
2 -IN
3 +IN
4 -V
5 NC
6 OUT
7 V+
8 COMP2

 

Possible Compatible Groups

  • 3080
  • 5534
  • 741

Members

  • LM308N
  • OP07D
  • OPA134PA

 

 

3080

1 NC
2 -IN
3 +IN
4 -V
5 AMP BIAS IN
6 OUT
7 V+
8 NC

 

Possible Compatible Groups

  • 308
  • 5534
  • 741

Members

  • CA3080A (metal can)
  • CA3080E

 

3094

 

 

1 FREQ COMP or INHIBIT INPUT
2 DIFFERENTIAL VOLTAGE INPUT
3 DIFFERENTIAL VOLTAGE INPUT
4 -V
5 Iabc CURRENT
6 EMITTER
7 V+
8 COLLECTOR

 

Possible Compatible Groups

  • na

Members

  • CA3094E

 

 

5534

1 BAL
2 -IN
3 +IN
4 -V
5 COMP
6 OUT
7 V+
8 COMP/BAL

 

Possible Compatible Groups

  • 308
  • 3080
  • 741

Members

  • LM301AN
  • LM318N
  • NE5534A

 

 

 

741

1 OFFSET NULL
2 -IN
3 +IN
4 -V
5 OFFSET NULL
6 OUT
7 V+
8 NC

 

Possible Compatible Groups

  • 308
  • 3080
  • 5534

Members

  • CA3130E
  • CA3130EZ
  • CA3140EZ
  • LF351N
  • LF351P
  • LM741CN
  • LM741EH
  • TL061CP
  • TL071CP
  • UA741CP
  • UA741TC

 


DIP-8 Dual Op Amps

 

 

4558

1 OUT 1
2 -IN 1
3 +IN 1
4 -V
5 +IN 2
6 -IN 2
7 OUT 2
8 V+

 

Possible Compatible Groups

  • none

Members

  • AD712
  • AN6552
  • CA1458E
  • CA1458G
  • CA3260E
  • JRC2068DD
  • JRC2114D
  • JRC4558D
  • JRC4558DD
  • JRC4559D
  • JRC4580D
  • JRC4580DD
  • LF353P
  • LF442
  • LM1458N
  • LM358N
  • LM358P
  • LM4562NA
  • LM833N
  • MC1458L
  • MC1458P
  • MC33178P
  • NE5532P
  • OPA2134A
  • OPA2604AP
  • RC4558D
  • RC4558N
  • RC4558NB/2
  • RC4558P
  • RC4559P
  • TL022CP
  • TL062
  • TLO62ACP
  • TL072CN
  • TL072CP
  • TL082CN
  • TL082CP
  • TLC2262CP
  • TLC2272CP
  • TLC272CP
  • uPC4559C
  • C4558C

 


DIP-16 Dual Op Amps

 

 

13600

1 AMP BIAS IN
2 DIODE BIAS
3 +IN
4 -IN
5 OUTPUT
6 V-
7 BUFFER IN
8 BUFFER OUT
9 BUFFER OUT
10 BUFFER IN
11 V+
12 OUTPUT
13 -IN
14 +IN
15 DIODE BIAS
16 AMP BIAS IN

 

Possible Compatible Groups

  • none

Members

  • LM13600N
  • LM13700

 


DIP-14 Quad Op Amps

 

 

3403

1 OUT
2 -IN
3 +IN
4 V+
5 +IN
6 -IN
7 OUT
8 OUT
9 -IN
10 +IN
11 V-
12 +IN
13 -IN
14 OUT

 

Possible Compatible Groups

  • none

Members

  • JRC3403AD
  • KA3403
  • LF347N
  • LM324
  • MC33178
  • MC3403N
  • RC3403ADB
  • RC3403AN
  • TL064
  • TL074
  • TL084
  • TLC2274
  • uPC4741C