Does it matter if you tune the Etherwave (std) pitch pots "way in" or "way out"?

Posted: 2/18/2009 11:17:44 AM
hewson

From: brooklyn, NY

Joined: 2/11/2009

Greets,

I was tuning my etherwave, and noticed that it seems like you can tune the pitch pots "wherever" to get a workable response. For example, it seems like you can set L5 wherever (from "way in" to "way out"), and then tune L6 to give you the right response from the antenna and the end result seems to be the same. Am I mistaken? Is there an optimal place to set L5 in terms of range, linearity or timbre?

also, i noticed that though the instructions say to short out the c28 cap leads, it is way easier (since the leads on my board are trimmed way down) to just use a piece of 20ga wire and temporarily connect the GND and VCA OUT to keep the volume at a steady level while tuning.

thx!!
Posted: 2/18/2009 5:25:23 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

You have to imagine that L5 and L6 are not pots but coils. Adjusting the slugs allows to vary their inductance by +/-10% which makes vary the frequency by +/-4.8% or +/-14kHz.
Since you hear only the frequency difference between both oscillators, there seems to be no difference between the different slug positions, but there is, since the working point of the variable oscillator has also an impact on pitch range and linearity:
The more the inductance of L5 is high (clockwise), the more the higher octaves are slightly compressed compared to the middle octave C4 to C5.
The more the inductance of L5 is high (clockwise) AND the antenna wire is far away from the aluminum foil ground plate the higher the maximum audible frequency (top of the pitch range).
The more the inductance of L5 is high (clockwise) the more the oscillator becomes unstable and more dependent from the ambient temperature. Sometimes it will even not start (no audible sound) until you touch the pitch rod for a moment, especially if the ambient temperature is low. Or the frequency will sometimes jump when you play in the lowest register.

So the first tuning principle should be to keep the inductance of L5 as low (counterclockwise) as possible and just as high as needed in order to obtain the desired highest audible frequency after having bent the wire in the right way. But be aware that the linearity will get worse with each halftone that you add.
Posted: 2/18/2009 5:35:05 PM
hewson

From: brooklyn, NY

Joined: 2/11/2009

AWESOME, thanks, Thierry, I think they need to put your post into the Etherwave manual!!
Posted: 2/18/2009 5:58:17 PM
Thierry

From: Colmar, France

Joined: 12/31/2007

Thank you! If all that was written in the Etherwave manual I would not have spent several nights on this... but I learned a lot in that time and it's pleasure to share this!

One day, just now it is too late for me (11:53PM in France), I may also write about the impact of the L5 setting on the overtone spectrum... The Etherwave is full of effects which appear strange in the first moment but there is always a logical explanation.

You must be logged in to post a reply. Please log in or register for a new account.