Laser Phase pedal question

[FUZZZZzzzz]

So,

I found a cool looking pedal at a yard sale two weeks ago. It's called the Laser Phase. I thought it looked very much like the Coron pedals from the 70s. It was very cheap so I took it home. There's no brand name on the enclosure. On the pcb it says PH 310. According to the little info on the internet (thank you effects database) it was made by Yu Brothers (indeed a Coron company), but also by other brands like Tronix and such. Anyway, as a good exercise I'm currently reverse engineering it. This will improve my skills, but also in the end result in a schematic for this rare pedal.

My question is as follows: It uses 6552 ic chip. These are not very common, but still available through eBay and such. (3 dollars each). Is there an ic that can replace these? To make it more modern and maybe get some advantages in sound quality?

datasheet
https://pdf1.alldatasheet.com/datasheet-pdf/view/13319/PANASONIC/AN6552.html

info effects database (mine looks like the picture except no brand and Laser Phase instead of Phase)
http://www.effectsdatabase.com/model/yubrother/coron/phase


video of the Tronix equivalent

[thermionix]

Seems to be a 4558 variant?

[FUZZZZzzzz]

I was wondering if it would be this simple. From looking at the datasheet.. I could also try the 5532 and 1458 ? Just use sockets, make sure the pinouts match and try them out? Almost all the datasheets use the term low noise. Is this just a marketing thing nowadays? I guess the expensive chips would have a better quality (unless they're just getting rare) but does it really make a difference if you stay in a lower price range?

[thermionix]

Yep, standard DIP8 dual opamp pinout.  Lots of options to try with a socket.  I can't imagine there would be any benefit to a 1458, but maybe some of the "better" opamps would have lower noise and/or more headroom.

[ElectricDruid]

+1 agree with what others have said. If you want something for that vintage original sound, go with the older dual op-amps like 4558 or 1458. If you're aiming to improve it, try something more modern like TL072.

Yes, "low noise" is a marketing thing, and what counts as "low noise" has shifted quite a bit since the term first appeared on an op-amp datasheet!

Finally, the 5532 is a somewhat different op-amp with a rather different behaviour (it'll cope with a low impedance output like headphones for example) but this means it may not work in circuits for which it was not intended. I don't regard it as a direct replacement like many others. It's a specific thing.

Good luck with the reverse engineering, and thanks for the efforts!

HTH,
Tom