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DIY Stompboxes => Building your own stompbox => Topic started by: mafew129 on July 13, 2015, 01:42:30 PM

Title: Ibanez Cs5 true bypass?
Post by: mafew129 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: http://www.freeinfosociety.com/electron ... hp?id=2315

(http://www.freeinfosociety.com/electronics/schematics/audio/pictures/ibanezcs5.gif)
Title: Re: Ibanez Cs5 true bypass?
Post by: R.G. on July 13, 2015, 04:20:23 PM
I would like to make it true bypass.
Why?
Title: Re: Ibanez Cs5 true bypass?
Post by: PRR 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. http://www.freeinfosociety.com/electronics/schemview.php?id=2315

> 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.