CLIPPING FOR Foxx tone machine clone

[Riffster]

I have a danelectro french toast pedal and was wondering if changing the clipping diodes would make it sound better.  Silicon 1N4001's?  LED's?  Any ideas or experiences?  I would assume that I could get more volume if I changed one diode to an LED??  Would it screw with the octave up effect?

[DougH]

Would it screw with the octave up effect?

Yes, especially if you only change one. The diodes are not for clipping per se but to rectify the signal to double the frequency and produce the octave-up effect.

[Mark Hammer]

Not so fast Dougie.  There are diodes for the octave extraction part, but there is also a diode pair further downstream for clipping, just ahead of the midscoop filter.

To answer Riffster's query:  Monkeying with the clipping pair would not screw with the production of the octave effect.  All of that happens safely well before the diode pair in question.  Would it be the tone you like?  Hard to say.  Certainly, raising the clipping threshold would put out more signal (something that the occasional FTM builder longs for, or has trouble achieving).  But like any diode-based clipping device, sometimes the most pleasing sounds come from having the threshold a little lower such that there is greater apparent sustain.

If it were my pedal, I would possibly try one GE and one SI or two SI diodes to bring the output level up a bit, but I wouldn't take the big leap to LEDs.  LEDs are nice for when you want to introduce just a light crunch (like a soda cracker).  This isn't the sort of pedal that benefits from that.

If there is anything that warrants monkeying with, it is probably the network formed by C2/C3/R4-6.  This forms another sort of "scoop" filter that straddles the emitter of Q2 and base of Q1.  My sense is that this is absolutely central to the delightful sounds and extremely robust octave that the FTM produces.  The shape of that scoop probably has something to do with the extent to which it is optimized for guitar, as opposed to being merely a generic rectifier/doubler.

[DougH]

In squeaky Gildna Radner voice: "never mind..."

[Mark Hammer]

What's all this fuss I hear about clipping pears?  How are people supposed to eat them?  Are they just supposed to stand on a ladder under the try and bite them on the branch?  How on earth are they supposed to be able to wash the bug spray off them if you can't clip them first?  If you shake the tree, instead of clipping them, they will get bruised when they land, and let me tell you young man, pears taste terrible when they're all bruised and scraped.

What?  Oh........clipping PAIRS.  Oh, that's different.  In that case.....NEVER MIND. 

[Gila_Crisis]

since we are are speaking about the FTM. i build one too and it's really a good fuzz/octave! (it's a hame people don't talk too much about it). mine as a massime volume too (i can't go up more than 9 o'clock!), and it's a preatty quiet unit as well.

maybe there is something i could do to enhance a bit more the octave? (like on the superfuzz, it's just wonderfull its octave sound, really massive)

[Pushtone]

Hey Gila,
Try the germ diodes Aron sells in the store for the clipping pear.
They will reduce the output so you can turn the vol control up to a normal range.

To increase the octave effect use the neck pickup and roll the guitar tone control all the way down if your not already doing that.