Tonepad Flanger FL301 build report

[dj_death]

Hi everybody, happy new year. Today i tested the Ibanez Flanger 301 from tonepad that i built yesterday. It worked right away after setting the bias trimpot and it works fantastic. This is the first time i use a flanger with guitar and i'm very excited. It's very clean and it gives dramatic sounds. I followed Fransisco's advice and i used in place of the clock
and regeneration trimmers panel mounted pots. With this mod I have the full control of the effect and i get really crazy sounds when setting them properly. At this time it is my favourite effect. Although all the parts are very close to each other it's not a big problem building this board. A big thanks to Fransisco Pena for his work in designing this complicated board.

John

[Fp-www.Tonepad.com]

awesome

Fp

[ethniccheese]

I recently had a similar experience with the Tonepad FL-301.  Works like a charm.  On your flanger, does the rate go from medium slow to ridiculously fast?  On my flanger I would like the rate to be able to go a LOT slower.  FP - Any suggestions on how to make this mod?  I'll try playing around with the circuit board, but this is a pretty complex breadboard.  Thanks, by the way, for the nice layout!

John - did you use 10k pots to replace the two trimpots?  This is another mod I want to make in light of the sweet oscillations you can get by tweaking these.

[dj_death]

Yes the same thing happens to me with the speed pot but i have no problem with that. I think it is caused because i use a linear pot for this. What type of pot you're using you should use a log pot. In place of the trimpots i used 10K linear pots and work fantastic. Good luck.

[Joep]

You need a reverse log pot to go from slow to fast clockwise.

A log pot should also work but then you go from fast to slow clockwise.

I got my reverse log pot from Smallbear

Bye,

Joep

[dj_death]

Yes i understand but this pot is only a variable resistor so wiring it reversed should make the trick i think.

[Joep]

Yes, you are right, but I you wire it reverse, it goes from fast to slow clockwise. Not a big problem, it's more inconvenient.

Joep

[Fp-www.Tonepad.com]

First, read RG's "Secret Life of Pots" at www.geofex.com to understand the differences between pot tapers.

Then, I suggest you save the yourself the trouble and spend a couple of dollars in a reverse log potentiometer from Small Bear.

IF you don't want to do that, then get a log potentiometer and wire it backwards, meaning you'll need to reverse pins 1 & 3. This will give you accurate control over the whole speed range, but the fastest speed will be on the counter clockwise side of the pot's rotation. The speed will go slower as you turn the pot clockwise. Not a big deal at all, considering now you can fine tune the speed.

Fp

[Samuel]

And just remember: all you have to do is label the pot "slowness" instead of "speed". :lol:

[ethniccheese]

I completely understand the taper of pots and am happy with the one I have.  What I am wanting to change is the range of speed.  I can't get mine to go slow enough.  I haven't tried a bigger value pot yet, but I think that might do the trick.  I am willing to sacrifice some of the top speed.

[Bill Bergman]

If you want a really weird sounds power it with 9 volts instead of 18v :shock:

[Mark Hammer]

The FL301 uses the same 2 op-amp LFO that many other effects use, although it is drawn in the schematic in a way that makes it look different.

The range of LFO speeds is set by the two back-to-back series capacitors C125/C126.  These are a pair of 10uf electrolytics.  When placed end-to-end, these form a 5uf non-polarized capacitor.  If you decrease the value of this capacitance, the range shifts upward proportionately.  Increase it, and the range shifts downward.  So, if it was currently (and I am making up numbers here) 0.5hz to 10hz, *doubling* the value of the capacitor would shift that to 0.25hz to 5hz.

The value of the pot + series-resistor also obviously sets the sweep rate.  In principal, you could extend the range of sweep rates by increasing the pot to 1meg so that the total resitance it was capable of inserting wouldbe double.  I,m no expert here, but my gut sense is that the circuit would underperform when the series resistance gets too high, perhaps by providing a poor waveshape.  So, best to simply shift ranges with caps, rather than push any single range too far with the pot.  That's just a hunch, though.  I'll let others weigh in on whether my concerns are foolish or justified.

The next standard size up from 10uf is usually 22uf.  A pair of 22uf caps in place of the 10uf would stretch out (slow down) the sweep time by a little more than twice.  Note that simply increasing one of them will not do what you want since series capacitance is primarily determined by the smaller of the two values.  You could up one of them to 100uf without seeing all that much increase in series value (10uf+100uf=9.09uf).

The bigger problem is whether you want to install a different pair of caps, or have some means for range-switching by toggle.  Straightforward replacement is the least problematic.  Switching in a second set of caps (e.g., another pair of 10uf) to increase overall capacitance CAN be done but it is difficult to do in any simple compact way unless you are willing to accept a loud pop when you switch ranges.  Unfortunately, having a second set of series caps in parallel, with one end lifted when you want the faster range, will produce a pop when you close the toggle for the slower range.  Presumably you won't hear it in bypass mode, so if you can remember to bypass before range switching, you'll be alright.

The extra set of caps should be oriented the same way as the first set.