ibanez fl301 vs fl301dx...

[swt]

hey guys!!. Just a simple question. Do you know the difference between fl301 and fl301dx?. Do you have schems for them?. i have the tonepad one, and was thinking of building it, but don't know if it's dx or not, and also which one sounds better. Also maybe it's simple to mod from that schem to the other if it's worth it. Thanks a lot for any replies...
PS:some say the dx is better, that why i'm asking...i know one is 9v the other 18v...

[George Giblet]

Don't have full info on the DX but here's what I pieced together sometime back,

Model      PCB              Chips

FL301 (narrow)   FL301A       MN3007, MN3101, 1xdual op aud, 1xdual op LFO
FL301      FL0401A       MN3007, MN3101, 7812, 2xdual-op aud, 1xdual-op LFO
FL301DX      MP-FL0501A  MN3207, MN3102, ICL82xxx, 2xdual-op aud, 1xdual-op LFO
FL-9              MP-FL0601    MN3207, MN3102, 3xdual opamps

Main change from FL301 to FL301DX was lower voltage delay chips.
However, the FL301DX PCB is very close to the FL9 but has a DC/DC converter (more headroom?).
FL-9 used different filters values and has a higher filter order to FL301.
I suspect FL301DX values and general design is more like the FL9


Forgot to mention: the tonepad schematic is the FL0401A pcb which is the non DX.

[swt]

well thanks a lot!! that's been really helpful. will continue the search for schems, but i think i might build the one from tonepad, and make some changes like adding the manual pot, maybe some diodes network, and pos-neg feedback. thanks again. if you happen to get those schems please let me know.

[bagudan]

Hi George Giblet. when You say that the  FL-9 used different filters values and has a higher filter order to FL301, is there any chance that you know wich parts one could change in the tonepad layout, to achieve this higher filter... if it´s possible?

[George Giblet]

There is filters before and after the delay chip in each case.

You can change the cut-off frequencies and the frequency-response shapes by changing the filter values but you cannot increase the filter order by changing values - you need to add another filter stage to increase order or remove a stage to decrease the order.    Removing a stages is easier than adding.  By playing around with the cut-off frequencies, and possibly the filter shape, you can make a lower order filter sound close to a higher order one without adding a stage.   Matching the -3dB points of the filters is a good start.

Based on the original schematics from the web:
                     
FL301:  Input filter is second order, parts around R109 through Q101.
FL9:      Input filter is second order, part around  R110 through Q101

FL301:  Post filter is second order,  parts around R115 through IC102
FL9:      Post filter is fourth order, parts around R117 through IC102
            and the added stage is R121 through Q102