BOSS OD-1 Chip Question

I see there are 2 version of the made in Japan OD-1.
One with the JRC 4558D, and the other one with the NEC C4658C.

Which one is better?

What's the difference between the two?

The one with the quad op amp 3404 is best, it's the 1st version. The dual op amp (8 pins) version did not sound as good at all.

That makes sense... from the Boss Book? I have one and sell them but no time to read it few OD-1s with a different quad op amp, but then they redesigned the board for the very very common dual op amp.

Mike, I should get you to mod a later OD-1 for me sometime.
<<

I'd love to. THen maybe you can compare it to the old one.
have only just now gotten a replacement.]<<

UGH!!!! Laptop thieves are abounding

Yes, that is a good one. It;s not really the CHIP that makes it sound better, but the way it works in that particular circuit.

There is one 3404 chip, it is a quad op amp (4 op amps in one chip, the 4558 is a dual op amp package). The 3404 has 14 legs while the 4558 has 8.

The OD1 was DESIGNED originally for the quad op amp. Then for some reason they replaced the quad op amp with a dual op amp and 2 transistors... not sure why as it would not save much money.

We can mod the newer OD1 into the old specs, by replacing the chip and transistors and a few more tweeks to original specs.

Do you mean there are 4 3404 in there?
Are these 3404 8-pin op-amps?
What do there look like?

Mine says RC3403ADB

are there other pedals from that era that use these chips?
It does sound better than 4558-based pedals I've played.