Author Topic: Ibanez Cs5 true bypass?  (Read 3165 times)


Ibanez Cs5 true bypass?
« on: July 13, 2015, 01:42:30 PM »
I'm rehousing an old Ibanez cs5 chorus pedal (comes in a flimsy plastic enclosure) and I would like to make it true bypass. For this i'm trying to get rid of the FET switching and have the effect 'always on' so I can then add the 3pdt.
How would I go about doing this? I've started by removing q1 and r54 but that just gives me clean signal all the time.
Schematic: ... hp?id=2315


Re: Ibanez Cs5 true bypass?
« Reply #1 on: July 13, 2015, 04:20:23 PM »
I would like to make it true bypass.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.


Re: Ibanez Cs5 true bypass?
« Reply #2 on: July 14, 2015, 01:58:46 AM »
Wasn't this discussed like a day ago?

Short the JFET, Source to Drain. Now the audio path is always effected.

While there are tricks to make the flip-flop always come up in the "flop" state, they are tricks and can be tricky. What you *really* want to do is pass signal from the delay chip to the output stage. Jumper on the JFET does that.

BTW, your URL was munged.

> Why?

Agree; except this pedal's "un-effected" path is more than most. It does a 800Hz preemphasis and a 800Hz deemphasis. Although it uses same-value parts both sections, and "should" cancel, and there should be plenty headroom above 800Hz, it's more than just ded-clean buffers.

Assuming 20% capacitors, the two corners *could* be a half-octave apart, and could be 3+dB of step in the frequency response, mid-band where it will skew bass/treble balance. Of course if that is offensive, then it will offend in the effected mode also, so the real fix is to match the two networks. But whatever.
« Last Edit: July 14, 2015, 02:04:50 AM by PRR »