# Best analog octave pedal around



## prodigal_son (Apr 23, 2009)

Thoughts, comments, suggestions..

The tone KWS gets in "Blue On Black" for example is simply amazing sounding. I believe he uses an Octavia. After listening to quite a few demos, the Roger Mayer stuff sounds the coolest to me.


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## mhammer (Nov 30, 2007)

The vast majority of octave-up fuzzes adopt the same core approach: they use a phase-splitter, rectify each copy of the signal coming off the phase splitter, and combine them. If you call up the schematic of any octave fuzz that interests you, you can recognize the phase splitter as a transistor with identical-value resistors between the emitter (where the line with the arrow is drawn) and ground, and between the collector (the non-arrow line) and the supply (V+). This produces two copies of the signal at equal volumes, one inverted with respect to the other.

Nailing a good audible octave, though, relies on maintaining _identical amplitude _of each copy of the signal up to the point where they are mixed. Make one copy even a little louder than the other, and the audible doubling simply evaporates. And since there are many ways in which the two copies to be combined could be slightly different from each other, great octaving can be hit or miss, even in units that enjoy a great reputation. Much like Fuzz Faces, there can be great Octavias, and mediocre ones.

I've made at least a half dozen different octave fuzzes, if not more (though I still have to make a Fender Blender), and while there is something quite pretty about a well-functioning Tychobrahe or Mayer Octavia (done both), I keep coming back to the Foxx Tone Machine. To my mind, this has one of the most dependably robust octave sounds. Happily, the guy who owned Foxx now owns Danelectro, so the Dano French Toast is an exact copy of the old Tone Machine circuit, albeit with solid-state switching. Still, its a small price to pay for something that will take you immediately and directly to the solo on "Purple Haze" or "Machine Gun" without any difficulty whatsoever.

Finally, note that for BOTH octave-up and octave-down units, generation of the added tone generally doesn't happen below the 7th fret, or for wound strings, and rolling the tone down on the guitar while using the neck pickup, is generally preferred in either case. The common problem is that harmonic content in the source "confuses" the circuit. Fretting higher up on unwound strings results in a stiffer string with fewer harmonics. Naturally, use of the neck pickuop with the treble rolled off helps in this pursuit.


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## NB_Terry (Feb 2, 2006)

The Foxrox Octron is great.


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## Jeff B. (Feb 20, 2010)

I'm also a KWS fan. I believe it was a Mayer model he used on Blue on Black. I have a magazine article from when that was released around here somewhere from that era where he gave a description of the gear he was using then. I really like the octave fuzz tone on the last record he released, How I Go. On that one he used both an original Tycobrahe and a Chicago Iron reproduction, sometimes using both at the same time running each one into a different amp.

Mark. The last time I was working on the Tycobrahe circuit I hit on something that worked quite well and sounded much more authentic than any diodes I tried. I used 2 extremely leaky Tungsram AC187 germanium transistors with the emitter and collector tied together and the base toward the output of the circuit. Not the conventional way to use them as diodes I think but it worked very well for me and gave octave up sounds at lower positions on the neck. The diode function on my multimeter gives a reading of about .110. I tried it with germanium diodes of that same reading but the results were not as aurally pleasing. The rest of the circuit was stock with the exception of the transistors. Q1 was a 2N5087 (I can't remember which way it was orientated). Q2 and Q3 were 2N5089. Might be something worth trying next time you're working on the Tycobrahe circuit or perhaps other other octave circuits. I only tried it with the Tycobrahe circuit so far.


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## mhammer (Nov 30, 2007)

One of the things that series diodes, whether they are discrete diodes, or transistors used in diode mode as you describe, and whether they are in all-active circuits (e.g., FTM, Superfuzz) or semi-passive circuits (transformer-based Octavia), is that there is a tiny, but discernible delay in signal onset. The best recorded example that comes to mind is Hendrix' "One Rainy Wish" from the Axis album. It occurs because the initial onset of the note doesn't exceed the forward voltage of the diodes, so it doesn't pass signal until reaching that threshold.

I huge a couple of parts drawers of cast-off Ge trannies, though I have to confess to never having measured their leakage. Between what you describe, and the few circuits that Steve Daniels has posted on the Small Bear site, using leaky Ge's (not to mention how great they sounded in person), I'm clearly gonna have to start measuring more than hfe.

Incidentally, I don't know if it has anything to do with historical shifts in component tolerances, but if you attempt the Octavia, sticking a small value fixed resistor in series with the 1k gain pot helps a lot. It's no secret that many pots fall towards the lower end of the tolerance, such that, for example a _nominal_ 500k pot might be 442k, moreso than it might be 527k. Maybe the 1k pots they had back then were 1k or higher, where they're more likely to be 900R now. I stuck a 330R resistor in series with the 1k pot in the last one I built and that sweetened it considerably. Octavias do NOT like high drive. Crank 'em too high and they just turn into lousy distortions.


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## traynor_garnet (Feb 22, 2006)

The Foxrox I had didn't track well. The best one I have used (believe it or not) was the Danelectro French Toast (see mhammer's post above). Should have never sold it, now I want another one! Maybe I will look out and they will do a French Toast in the newer Cool Cat series . . .

TG


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## Jeff B. (Feb 20, 2010)

That reminds me. I had used a 2K pot instead of the 1K in that circuit. 

I didn't measure the leakage or gain on the transistors. I bought a box of them off 100 of off ebay and out of the 80 I tested only 2 were not leaking like a hemophiliac break-dancing on a bed of machetes.
I tried some that were known to be scrap and the results were the same. I also tried other good, low-gain and low-leakage germanium transistors and to me the extreme leakage one sounded better.

I was messing around with Sziklai parings of transistors last year. Quite promising and interesting. I've been trying to get some more time to experiment with them ever since. I've been wanting to try them in a Big Muff circuit but haven't had the time yet. I have a couple of schematics somewhere in the growing heap of scribbles and notes from when I was experimenting with them last year that worked well.


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## NB_Terry (Feb 2, 2006)

The French Toast is a great fuzz pedal. I sold a Fulltone Ultimate Octave when I got the $20 Dano.

As for tracking with the Octron; it seems to have problems on low notes occasionally, but upper range notes track well on the 2 Octrons I've owned. When it glitches on low notes, it's a funky analog type sound, so not bad sounding at all IMO.


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## Jeff B. (Feb 20, 2010)

Running a compressor before an octave pedal usually helps a bit with the tracking. As does reducing the range of frequencies going into the pedal.


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## mhammer (Nov 30, 2007)

It's probably been mentioned elsewhere, but the first time buyer/user should note that ALL octave-up fuzzes that uses the "engine" I described earlier will produce sideband products when you bend notes, especially with double stops. That is, it will sound like a ring modulator where you're bending the note upwards in pitch but you still hear something going down in pitch. That's probably why the Dan Armstrong Green Ringer - which is an octave fuzz - is called the Green _Ringer_.

Compression is VERY useful for improving octave-*down* tracking, though personally I find much less advantage for octave-up. Jeff's absolutely correct about keeping the reins on the frequency content of what you feed them, though.

Lastly, note that just about _*any*_ octave-up fuzz, whether it is a $20 French Toast or a $500 custom-order clone of a Tychobrahe made by Roger Mayer himself, will produce a reasonably decent sounding emulation of the drone of a Coral Electric Sitar if you: a) set the guitar to the bridge pickup, b) pick really close to the bridge with a pick, and c) don't set the gain/drive/distortion too high. It won't be as clear as an EHX Ravish, but provides a nice diversion.


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## keto (May 23, 2006)

Yet another vote for the Foxx Tone Machine/French Toast. I built and bought a bunch, the FTM I built for myself ended up being the keeper. Bonus, I put the octave on a footswitch (might be as per original FTM? Don't know if the French Toast does this) so have a usable fuzz (sorta Superfuzz) in addition to the octave. Best octave tracking and range of the ones I've tried. If you want a little more synthy sound, the MicroPog is good and does both up and down.


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## Ti-Ron (Mar 21, 2007)

Any good words on the RI ones?
http://www.foxxstore.com/Tone-Machine-TM-01.htm


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## mhammer (Nov 30, 2007)

The POG, being a digital pedal will not produce the sideband products that the FTM, and similar, produce. Some folks dig that, some don't. Obviously pricier than a Dano FT, but a very flexible pedal. Mike Matthews recently described it as THE best selling EHX pedal.

Re: Re-issue FTM. It's the same circuit as the Dano FT...really. If you prefer the packaging or layout of the Foxx, and don't have the means to repackage a Dano, fine. If you just dig the fuzzy coating, fine. But even though it is hard to believe that a $20 Dano pedal is the same thing, it really IS.


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## prodigal_son (Apr 23, 2009)

Thanks for the response thus far. After reading this, I have taken time to listen to demos, etc.. of the various pedals mentioned. Unfortunately I do not have any of them at my disposal. Does anyone on here actually own one of the newer or older Roger Mayer units? I would appreciate hearing more thoughts about this particular unit. Cheers!!


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