DIY Akai Unibass.

nelson · May 05, 2005, 01:11:46 AM

Do you guys think this pedal is do-able on a diy level? using various analog effects?

http://filters.muziq.be/model/akai/unibass

It has distortion, octave up, a 5th above or a 4th below the octave sound seperate out for distortion/octave up and an out for clean bass signal.
it allows clean octave up.
you have the option of sending it all to one bass amp, or sending only the octave up/4th below/5th above to a guitar amp.

sounds like a useful tool for bass And a great project.

What circuits could be combined/played with to achieve this effect?

I was thinking of the bass paralooper to begin with.

Any ideas? :?:

Jaicen_solo · May 05, 2005, 03:53:15 PM

ERmm, I'm not 100% on this but I believ that the Uni-bass is a digital FX unit.
Probably not diy-able.

*b

loki · May 05, 2005, 04:10:57 PM

yes, it's digital, like the AKAI Deep Impact

nelson · May 05, 2005, 04:53:01 PM

I know its a digital effect, I am thinking it would be possible to make a workalike out of analog circuitry.

I dont think the 4th above and fifth below the octave sound will be possible with analog circuitry.

A bass distortion, an octave up, and a mixer circuit. all in one.

I think its possible, I am just looking for ideas. Possible circuits to join together.

Jaicen_solo · May 05, 2005, 07:51:07 PM

Ah, Ok then yes it is possible.

I've just designed a synth sounding Bass fuzz with a blend feature for a client. That has an octave up function, similar to the rambler on the circuit snippets site.

Works a treat.

*b

nelson · May 05, 2005, 09:39:04 PM

The interesting thing about the circuit, is the ability to route the octave up/distortion signal to a seperate amp, while allowing the clean signal to pass onto a bass amp.

seanm · May 05, 2005, 10:44:50 PM

Quote from: nelsonI know its a digital effect, I am thinking it would be possible to make a workalike out of analog circuitry.

I dont think the 4th above and fifth below the octave sound will be possible with analog circuitry.

A bass distortion, an octave up, and a mixer circuit. all in one.

I think its possible, I am just looking for ideas. Possible circuits to join together.

I do not think the distortion is for bass, but for the octave up to make it sound more like a guitar. As a first shot I would leave out the distortion since you can just add a distortion pedal after the effect. The distortion is suposedly the weakest link in the Unibass.

Here is my idea of a high level design:

For the buffers, see Jack Orman's Basic Buffers article. For the high pass filter: http://beis.de/Elektronik/Filter/Filter.html. You are on your own for the octave up .

nelson · May 06, 2005, 02:27:34 AM

After looking for a clean octave up I came across this a MOS Doubler a CMOS based clean octave up.

The page had a link to a geofex article/project, but the link was dead, does anyone have the schematic?

seanm · May 06, 2005, 02:36:58 AM

Quote from: nelsonAfter looking for a clean octave up I came across this a MOS Doubler a CMOS based clean octave up.

The page had a link to a geofex article/project, but the link was dead, does anyone have the schematic?

I just tried the Mu Doubler, a newer version of the MOS Doubler. http://www.geofex.com/Article_Folders/jfetdoub/mudoubler.htm

nelson · May 06, 2005, 05:14:08 PM

I am not entirely clear if this is able to produce clean octaves, is it?

seanm · May 06, 2005, 06:41:53 PM

Quote from: nelsonI am not entirely clear if this is able to produce clean octaves, is it?

No not clean octaves. I may have a mistake in the build, since I did build it very late last night, but it has a great sound to it. I may build an overdrive pedal around this. Also, I found it works better if I put a booster in front of it.

The quest for a clean octave continues....

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DIY Akai Unibass.