New schematic for you all: Guyatone FL3 Flanger

[Praying_V]

Hey everyone.  A few years ago I traced out a schematic for the Guyatone FL3 mini flanger.  I'm not sure if it'll interest anyone, but here it is.  The signal path is very similar to the Boss BF-2 and CE-2.  The LFO is different; I'm not sure of any other pedal with a similar sweep... Its quite asymetrical.

This is not a verified schematic, but I'm sure its at least 99% correct, if not perfect.  I probably wouldn't bother building one from scratch, as you can find these pedals on ebay regularly anywhere from $40 - $99.  But with the schematic, you could mod one any way you like, from analog chorus, to flange...  Makes a cool project-  I'm sure its the SMALLEST analog flanger you'll ever see.  Its about the size of the Dano mini's, but in a nice metal enclosure, with a nice metal stompswitch.  All the parts inside are numbered on the silkscreen layer, so its simple to mod.  Also, the unique LFO might be of interest...

I'm not sure how to post pics, so I'll do it like this:
Schematic: http://www.geocities.com/kiyomasa_demo/Guyatone_FL3_Flanger.GIF

Here's a pic of the un-modded pedal, to show its small size (barely bigger than the humbucker):
Schematic: http://www.geocities.com/kiyomasa_demo/guyatoneflanger.jpg

And here's a pic of the one I modded.  Notice two tiny slider switches I added on either side of the stompswitch:
Schematic: http://www.geocities.com/kiyomasa_demo/guya.jpg

have fun ............................................................................ken

[Mark Hammer]

I'm not sure what's more appealing, the schematic, the sexy pink chassis of the pedal, or those parts bins behind the pedal in that last picture! 

Thanks for that.

BTW, what were the 2 mods you did?

[Praying_V]

Actually, they were mods that you've recommended for flangers, Mark!  One switch changed the timing cap in the clock circuit, and the other opened the dry signal path.  Simple mods, lots of good tones.

For anyone interested in similar mods:
By increasing the timing cap, you change the delay of the modulated signal.  If you slow it down, you go from a sweeping flange sound, to a modulating chorus sound.  If you lift the dry signal, you go from chorus to vibrato.  All analog... Not bad from a little 3" box!

..........................................ken

[stm]

Cool! Thanks for sharing.

[Praying_V]

I've been informed that the links are dead.  So here they are again, In case anyone ever wants the schematic:



Here it is before mods (to show its small size):


And here it is with two tiny switches added:

[Gone Fission]

I've been looking for enough info to see about fixing my FL-3.  Nice sounding little pedal, but when I set it for full jet plane flange (max depth, slowest speed), the thing will stop flanging near the bottom of the swoop.  On other flangers I understand that there is a trimmer to adjust the waveform, but I can't spot one in my pedal or on the schematic.  Anyone got any ideas?

(I bought the pedal along with an MC-3 chorus, both used, and both with evidence of batteries left to leak in the pedals.  I'm thinking some general cleanup beyond fixes might be handy. So I'm doing searches on that, too.)

[jackalkirk]

Dang, bet that guitar has some nice sustain with that straight-through neck, what type is it?  Ibanez?

With regards to the pedal.  Mine is real hissy.  Its said to have a volume boost.  Is this whats causing the hiss?  If so, should I find a resistor early on and parallel another one onto it to drop the resistance (say drop R2 to 235k) and thus lower the gain/hiss?  If not, should I pick a resistor and parallel a cap on it to creat a low pass filter (say onto c3 or c4)?  I'm pretty new to this so any advice would be helpful.  Thank you!

[jackalkirk]

Correction, I meant so say find a capacitor and parallel a resistor onto it (say c3 or c4)?  Oops.  Thanks.

[doc_drop]

Hey, thanks for posting that schematic. I just got some cheap E-Bay MN3207's and MN3102's. I've been looking for this schematic since this seems like a good flanger circuit to DIY with those chips. And next thing I know you post exactly what I needed. With mod ideas as well.

Sometimes you get lucky!

[lcan]

Hey, hello guys, i know this is a very old tread but did anyone succeded on building this from schematics? i would like to try it (acually already have it on eagle layout), if any one could help me with zener values it would be very appreciated, also notice that there are some omited resistors and capacitors (at least in numbering like missing r18... any thoughts?). Cheers.

[armdnrdy]

The zener (D5) is just for a battery indicator.

You can look at any Boss, Ibanez, etc. schematic for a ballpark.

If you aren't using a battery...or don't want the indicator...leave it out.

The other zener is overvoltage protection for the BBD.
Once again...look at a similar circuit which uses a MN32XX BBD.

[lars-musik]

Hi Ican,
I am working on this at the moment. It doesn't work like it should - yet. But here's a build document with a somewhat modified schematic that has reportedly been verified with all the values:

https://www.dropbox.com/s/6pasoy267uwvdkk/Solderman_FL3.pdf?dl=0

Good luck!

[armdnrdy]

Hi Ican,
I am working on this at the moment. It doesn't work like it should - yet. But here's a build document with a somewhat modified schematic that has reportedly been verified with all the values:

https://www.dropbox.com/s/6pasoy267uwvdkk/Solderman_FL3.pdf?dl=0

Good luck!

I noticed that the over current zener was replaced with a standard reverse polarity diode.

Unless you know that this effect will always be powered by a regulated 9 volt power supply....
I would replace the zener.
Many wall adapters output voltage greater than what they are "labeled" for.
I have a 12 volt adapter that outputs close to 16 volts!
The MN3207's maximum rating is 11 volts.
I have yet to see a factory design that doesn't use a regulator (usually 8 volts) or zener to protect the BBD from over voltage.
Better to be safe.....you know the rest!