Old MXR Phase 90 noise.

[Nuts]

Hello,
I got an old MXR Phase 90 which got some hiss noise at some part of the sweep.
After doing some online searches I've found that it might be the IC's, they are 6X 741.
Some guy was suggesting someone to replace them with OP27's, do you think it can solve my noise problem ?
SmallBear doesn't sell OP27's, where else can I get them ?
Thank you.

[Seljer]

The 741 is a single opamp IC. You can generally replace it with any other single opamp IC with the same pinout. I'd wager that just something like a simple TL071 will work miles better than the ancient 741 opamps (though they sometimes don't like the function in the low frequency oscillator section -> it the four chips in a row that are the phasing stages that the audio passes through that are most critical and one of the remaining two that functions as a basic buffer on the input side).

[Nuts]

Thanks for the reply.
So do you think the TL071's will be better than the OP27's for a phaser ?

BTW, can anyone tell which version of the Phase 90 I got ? because when I bought it used a few years ago, it was inside a Phase 45 case for some reason.
Could it be an original script logo version ?

I replaced the caps though...

[Seljer]

The OP275 won't fit, it's a dual opamp.

The TL071 won't be better than the OP27 (look up the specs for each in their datasheets) but it's a whole lot cheaper and still would be an improvement on the dinosaur 741 .


The fanciest single opamp in a DIP package I could find on Smallbear is the OPA134.