MODDING Ibanez CF7 Chorus Flanger

[PennyroyalTea2]

This is pedal can do a nice relaxed verison of Nirvana Radio Friendly , that song used a POLYCHORUS.

Here is me doing it briefly ,

Now here is a picture I found of the inside , anything here that could maybe be changed for it to be even close to polychorus ?



Thanks.

[Mark Hammer]

The M50198P chip is a 9-mode digital delay.  The datasheet - http://www.datasheetarchive.com/M50198P-datasheet.html - suggests there are a number of interesting delay times available, but if I were you, given the nature of the question that you asked, I'd steer clear of monkeying with this thing.  The possibilities for irritating noises are too great.

Not unless someone has inside info on how the stock design switches between flanger and chorus mode.

[PennyroyalTea2]

That's very true . I do not mind if I loose the FLANGER End. Just so I can use the CHORUS.

CF7 is 9V Power. Doesn't the Polychorus XO use some type of 9 Digital chip ? Perhaps just simply switch it for that ?

[PennyroyalTea2]

Here's a POLY XO Inside.

[PennyroyalTea2]

Those's three 4558D JRC , 1 can be found in a SMALL CLONE CHORUS.

[PennyroyalTea2]

The

74HCD4AP is on the side where the CHORUS/FLANGER switch is

29404D JRC is on the side where the NORMAL/KRAZY Switch is

The CF7 is 9V Powered.

[PennyroyalTea2]

The thing I basically I just want to address is.

I get the cool twists and bends I want but the Effect still almost sounds like a plain bare guitar tone. SO I am thinking it's the

74HCD4AP I need to change ?

But I am really thinking it's the 3 JRCs as that's what's found in CHORUS Pedals.

[mth5044]

Unfortunately it's not going to be that easy. The JRC4558 are simple dual opamp chips used in tons of circuits, from chorus pedals, to overdrives and everything inbetween. They don't mean much to the effect you are describing. The 74HC04AP is a bank of generic hex inverters that changing won't do anything. The JRC2904D is another dual opamp.

You have two different effects and it is not as simple as getting similar chip names between other pedals.

The chip M50198P is the heart of your pedal. A lot of the circuitry there is to support the function of that chip. In the polychorus, the heart is between the MN3008 and MN3009 and much of the other parts of the circuit are there to support those chips. The supporting circuitry of each chip is very different. You won't be able to do a simple swap to change the sound.

If you want to stick with your original pedal, your best bet to change it is to get the schematic so we can see what's going on and offer insight on what aspects to change (it won't be any of the IC's). If that's a digital chip, the sound is likely programmed into the chip already and you'll be SOL. But that just means you get to build a new pedal!

[Fender3D]

As MTH said it's not going to be that easy...

According to schematic and datasheet, M50198P should provide 5ms when in flanger mode and 20ms when in chorus mode.
This, of course, IF clock is @ 3.27MHz.
I don't know if CF7's clock runs that high, but in order to be in the MN3009's delay ballpark it should be double than that (assuming M50198P can run over its max 6MHz...).

LFO and VCO are more or less the same as other analog chorus/flangers.

That said, it should be a matter of comparing LFO and VCO's part values, checking stock CF's clock(s) and comparing it(them) to Poly's clock(s) then you might get closer your goal...

BTW since it seems you have no clues how CF7 or chorus/flanger work, you'd better build or get a new pedal, as MTH said