Audio to Pitch-CV Possibilities?

[iandunham]

Hi there,

I'm new to the forums, but I've searched and haven't found any topics that directly address the possibility of a device that translates an audio signal into a control voltage that a Slim Phatty could read through the Pitch CV input. I really like the idea of having the timbre of my SP added to an existing bass rig, but don't want to invest in a MoogerFooger.

I've tried the Sonuus B2M, which is supposed to do this for MIDI, but it absolutely sucks. Also, I know the Roland GK-3B translates audio into MIDI, but (1) it's really pricey and (2) it doesn't seem to work that well for low tones, given that the pickup can't identify the tone until well after it's been sounded.

With a voltage-translation device, it doesn't seem like you'd have to wait until the note's been identified to decode it, since it's all in the analog domain, but that's coming from someone with a very basic knowledge of electronics.

Thanks in advance,

Ian

[_DemonDan_]

I know the Roland GK-3B translates audio into MIDI, but (1) it's really pricey and (2) it doesn't seem to work that well for low tones, given that the pickup can't identify the tone until well after it's been sounded.

Hi Ian,

A picky point but, success with Instrument Audio -> MIDI convertors depends on lots of little details.

The GK-3B Pickup has no translation components in it. It is merely 4 or 5 individual bass pickups. Each of these seperated pickups have their own wires going to the GK-3B's 13-pin female connector.

So, the signals are still regular analog audio as they go down the 13-pin cable. It's not until they get to an external conversion box that any MIDI is created. It's there that you start to encounter latency. (Prior to the conversion, everything was still moving at the speed of electrons.)

The problem is that it takes 1 1/2 cycles of bass (or guitar) string motion to correctly identify the pitch. The lower the bass note, the slower the detection time. Every octave down is twice as slow as the octave above it.

The Moogerfooger I'm guessing you're talking about is the FreqBox. While it will let you play the internal oscilator via an external audio source, it's tracking that signal via Oscillator Sync. There is no way to get Audio -> Pitch CV from it which represents the external audio's pitch. That CV Out is based only on amplitude. It's an Envelope Follower, which is only following the external audio's amplitude.

None of this information, sadly, is a solution for you in any way. It's only a clarification.

[iandunham]

Hi Dan,

Thanks for the reply.

It seems like, even at its best, that the GK-3B and whatever it's connected to (even in the most ideal situation) has a difficult time tracking with low frequencies. As you point out, 1 1/2 cycles is the fastest any decoding can take place.

Concerning the FreqBox:

While it will let you play the internal oscilator via an external audio source, it's tracking that signal via Oscillator Sync.

So, does Oscillator Sync exist outside of this device in some other context?

[mmarsh100]

Pitch->MIDI is better on guitar but even then the sixth string has some latency, precisely because of what Dan described. I haven't found any great solution for this. I also tried the Sonuus for guitar and even though it is mono, it is no better than the Roland solution which I also have.

That much said, for recording the latency is less of a problem as you can edit the notes after the fact. Tedious, but it works.

And another solution is the Ztar: http://www.starrlabs.com/ it is sufficiently guitar-like without the latency. Downsides: price and complexity of setup and operation. I've had one for years, lots of fun. I find that I don't play it the way I play a regular guitar, though, and this is a plus in many ways: new inspiration

Finally, if you are looking for fluid synth lines not from a keyboard, there's always the Akai EWI and it's brethren...

*EDIT*

It occurs to me that for bass lines you could use the Sonuus or Roland and play the high strings for low latency (though tracking might still be a bit of an issue) and simply transpose the synth...