Anybody willing to explain the Oxide (Ibanez Mostortion) 3-band EQ circuit to me?

[ctelecaster]

Hi,

Would like to learn more about the 3 band EQ on the Oxide (Ibanez Mostortion) - I can't seem to wrap my head around how the circuit works. Interested specifically in learning more about which components determine the frequency range of each band of the passive EQ, as I'd like to play around with tuning the response to my tastes.

If anyone smarter than I would be willing to give me a quick rundown, I'd be super grateful. Thanks! Attached is the schematic for reference.

 

[eh là bas ma]

Unfortunately i won't be able to explain how it works, i will follow this interesting thread and learn as much as i can.

I also built an Oxide distortion, all i can say is that the EQ is among the most effective EQ i ever tried.

I am surprised that you are not fully satisfied with it.

If i may, i will quote Mr Hammer, a famous diy wizard, about this circuit :

"I've built a few Mostortions, with 3260 and 3240 chips. There is an audible difference between the two, but I can't say I like one better than the other. They both sound great. The real secret to this little beast is the use of a 2+2 diode complement (just like a Timmy) and the terrific 3-band EQ. Personally, I don't feel it benefits from mods. I say "Enjoy it as is" and leave the diode switching to someone else. "

https://www.diystompboxes.com/smfforum/index.php?msg=1256606

I wanted to try a change of clipping diode, just by curiosity. I did it despite this advice, and i have to admit that it's not really useful after all.

Here is a tiny bit of information i could find on Aion's website :

"The 3-band passive tonestack is similar to Marshall and Fender tonestacks, and nearly identical to Peavey solid state guitar amp tonestacks. It’s a passive tonestack, contrasted with the typical Tube Screamer tone control which is driven by an op amp. In the process of shaping the tone, the overall signal level is cut, so it needs to be followed by a gain recovery stage in order to get back up to a reasonable volume level. The second half of the CA3260 op amp provides a gain of 15 dB, with the R-C filter having a corner frequency of 15 Hz—in other words, a full range boost."