# Opa2604 substitute.



## dlazzarini (Apr 19, 2020)

Hey guys I’m sourcing parts for the Wonder Drive. I’m finding that the opa2604ap is obsolete. I can find plenty of them on eBay but I’m very leery about ordering IC’s from China. I don’t want to get bit with a phony. What would be the next best thing?


----------



## Nostradoomus (Apr 19, 2020)

If you want to get fancy and expensive you can try an OP275...if you want to be reasonable use a TL072/5532/etc


----------



## Cybercow (Apr 19, 2020)

*Dual Op Amp Equivalents*:

AD712 - Slew = 16V/µs
CA3240 - Slew = 9V/µs;
LF353 - Slew = 13V/µs 
LM358 - Slew = 0.3V/µs (@ unity)
LM1458 - Slew = 0.5V/µs
LM2903 - Diff. Comparator
LM4558 - Slew = 1.7V/µs 
LT1490  - Slew = 0.06V/µs
uPC4570 - Slew = 7V/µs
LM4560 - Slew = 5.5V/µs 
LM4580 - Slew = 5V/µs
LM833 - Slew = 7V/µs
LMV652  - Slew = 3V/µs ~ 0.12 mA; 
NE5532 - Slew = 9V/µs 
OPA1642 - Slew = 20V/µs 
OPA2107 - Slew > 9V/µs
OPA2134 - Slew = 20V/µs 
OPA2604 - Slew = 25V/µs
OP275 - Slew = 22V/µs 
RC4559 - Slew = 2V/µs 
TL022 - Slew = 0.5V/µs ~ 0.13 mA 
TL062 - Slew = 13V/µs
TL072 - Slew = 13V/µs
TL082 - Slew = 13V/µs
TLE2072A - Slew = 35V/µs


----------



## Chuck D. Bones (Apr 19, 2020)

Other design considerations are noise and input bias current.
Slew rate is not too much of a big deal considering that the max slew-rate of an 8Vp-p 10KHz sinewave is 0.25V/us.


----------



## dlazzarini (Apr 19, 2020)

Thanks for the quick replies guys. This pedal is pretty much a staple in front of many 5150’s so I want to keep it as close to original as I possibly can. I’m not against spending a little more on the right op amp. What would you guys consider the closest?


----------



## Chuck D. Bones (Apr 19, 2020)

The thing that makes the difference between opamps in pedals like the Wonder Drive is how they recover from saturation.  That is not in the spec sheet, so your best bet is to install a socket, try what you have and settle on what sounds good.  Don't be too surprised if they all sound about the same.  The OPA2604 is advertised as "low distortion" which is a bit ironic in this situation.

This store claims to have some.  I have no idea if they are legit.


----------



## dlazzarini (Apr 19, 2020)

Chuck D. Bones said:


> The thing that makes the difference between opamps in pedals like the Wonder Drive is how they recover from saturation.  That is not in the spec sheet, so your best bet is to install a socket, try what you have and settle on what sounds good.  Don't be too surprised if they all sound about the same.  The OPA2604 is advertised as "low distortion" which is a bit ironic in this situation.
> 
> This store claims to have some.  I have no idea if they are legit.


I was just looking over the website you linked. Read up about them. They seem pretty legit. Have you ever ordered anything from them Chuck?


----------



## Chuck D. Bones (Apr 19, 2020)

Nope.  Just found them searching for info on OPA2604.


----------



## Barry (Apr 19, 2020)

Odd they have so many in stock


----------



## Nostradoomus (Apr 19, 2020)

Yeah that sounds like a dream come true to audiophile types (aka it’s fake)


----------

