recomend a good DIY bass octave up

[Tomass_17]

ive been sifting through tonepad, moosapotamus, general guitar gadgets and geofex for a nice octave that will track very well with bass. I dont mind fuzz but i would rather not have it if its possible.
So which octave up is going to be the most strongest octave out of this lot:
*Brass master
*fOXX Tone
*Octup
*Omni Drive
*Neoctavia
*Green Ringer

if there are any suggestions for any others please feel welcome to say so

[Johan]

I hav'nt built it yet, but I have had my eyes on R.K.Keen's mu-doubler for quite some time. I thinkt threre is a lot of promise in that little bit of circuitry...follow the geofex link above and scroll down
johan

[Processaurus]

I hav'nt built it yet, but I have had my eyes on R.K.Keen's mu-doubler for quite some time. I thinkt threre is a lot of promise in that little bit of circuitry...follow the geofex link above and scroll down
johan

I couldn't get that one (no octave) or Geo's JFET doubler (way quiet) to work right, has anyone else?  I'm interested in the squaring octave sound too, its a compelling alternative to the full wave rectifier designs.



Don't forget the Ampeg Scrambler, it and the Foxx are the gnarliest.  For the strongest octave, you need a low pass filter before the octave, to get rid of overtones and have more fundamental.  Theres a thing at GGG I did that is a lo-pass filter sandwiched in the green ringer, but the idea works for any analog octave up.  Here's a good article (where the idea for the GR thing came from)

[Meanderthal]

 I'm currently populating a GGG Brassmaster (thanks, R.G.!), it's definitely the one on that list I'd pick! I want it for the psychotic tuba thing it can do, (it'll do other stuff too!) but it's the only octave up you listed designed specifically for bass. I had all the resistors, caps, and the transformer, but now I need the damn weird transistors... sheesh, it's always something...

[electrobuster]

The Brassmaster is the way to go if its for bass. Built one a couple of months ago and is definatley the best bass effect I have tried.Sits well in the general mix.
Meanderthal, I used 3904's and a mpsa13 for the darlington. You just have to insulate one leg and twist the pinout for BCE and not CBE.

[Meanderthal]

 Really? Cool, I have... too many 3904s, and I might have a couple mpsa13s, or at least mpsa18... thanks!

[Tomass_17]

so this low pass filter, would i just run one of those before the octave pedal, or do i have to combine the 2 into one. But also the thing about the alternative transistors will allow me to build a Brass Master.

[Processaurus]

so this low pass filter, would i just run one of those before the octave pedal, or do i have to combine the 2 into one.

I'd put it in on a little board inside the octave pedal, preceding the octave circuit.  It does the same job as rolling down the tone on your instrument, except it works better at rolling off highs, and if its in the pedal, there's no messing with your tone knob every time you switch the effect on.

[aron]

I dont mind fuzz but i would rather not have it if its possible.

$$$ but good but not DIY - EH HOG!

Amazing octave up.

[Tomass_17]

yer id love to get a HOG but, im a bit strapped for cash, plus i enjoy building my own things anyway. Whats a good low pass filter to build then? (sorry still a little new to the effects world). Also regarding the fOXX Tone Master the only germanium diodes i can get from Jaycar are OA-91, will these still work?

[Mark Hammer]

The simpler thing to do is to use a split-n-mix strategy, in which a nice strong octave is derived however you can get it, highpass filtered to remove the fundamental, then mixed back in with a clean bass signal.  It wouldn't be absolutely clean, but it would be cleaner, and suitable for bass than doesn't intrude into the turf of other instruments too much.