OT - Dinah-Mo Humm

[Wink0r]

What you really need is a continuously variable low voltage DC power supply. Similar to: http://www.electroniccity.com/shoppi...t.asp?prid=540

[John Ludlow]

That does sound perfect in concept - replacing straight batteries with a regulated power supply. But it says that it's 1.5 to 35 volts. What I really need is zero to 3, don't I? Plus - I don't want to build a kit.

[Wink0r]

You could trick it into providing lower load voltage with 2-3 diodes. That was more to show what you need without inducing sticker shock than a real suggestion. I had the feeling that you would not really be in to a kit. The e-bow may be cheaper than a lot of what I saw as far as 0-X volt power supplies. You may be able to find something surplus or used. (or maybe barrow/rent from a repair shop that has one - evening or weekend when they are not using it)

[John Ludlow]

Guys - I appreciate all of your great ideas. I think I'm defeated here though. It's been fun!

[John Ludlow]

I bought an EBow last night. As I read the directions I began to believe that I understood why my previous efforts had not worked. The EBow instructions tell you that you should point the business end of it at your electric guitar pickup. Dinah-Mo does not have an installed pickup under the string and I never pointed any of the three incarnation of my transducer at the pickup that I would also hold to the side of the string to amplify it. The directions seem to indicate that the EBow picks up the vibration in the string and amplifies an electromagnetic version of it directly back into the guitar pickup.

But, this turns out not to be entirely true. I tried it out on my Parker Concert that has a GK-2a mounted on it. The truth is that the best signal I get is nowhere near the pickup. It's at about the place where the neck pickup would be if it had one.

In the EBow, the active string travels in a shallow tunnel. It may be that the tunnel contains the 'C' type coil that Wink believes may be the best way to do it. Or - maybe the tunnel is just a convenient way to keep the EBow from touching the string and stopping it's vibration.

Ultimately, I think this is going to work. I do have some difficulty keeping the output from leaping into fifths and octaves above the primary. But, if I work at it I find I can ultimately hold a note for a significant length of time - long enough to record it. Plus, I played around with the pitch converter in the VG-8. It's capable of converting any note either 2 octaves above or below the actual frequency of the string, in half steps. With a little luck I think that means that I have a six octave range of non-fretted notes as potential recordable output.

The only real drawback of this method over what I was planning is that the EBow amplifies whatever is going on the string now. It's harder to keep from moving into harmonics than with, say, the nail coil. I was hoping for a rich variety of partials over the primary frequency, but - not for one of them to dominate the sound. Once one becomes a little loud it's really hard to get it back under control again because the EBow acts as a feedback loop and stops feeding the string the original frequency - not unlike normal guitar amp feedback.

One thing that might make things a lot easier for me is if I recorded the GK-2a output directly and then played that back into the VG-8 as the signal to be pitch modified. It would mean that if I got one good original recording, I could use it over and over to create 4 octaves worth of samples. It would both solve the harmonics problem plus afford me a lot of consistency between samples. I remember that there used to be a guy who made acoustic guitar pickups that worked with Roland-style 13 wire guitar synth inputs (like a GK-2a). We were both fixtures in the VG-8 mailing list. He made a breakout box for his stuff that allowed you to record output from each of the six strings separately. It also worked with a GK-2a. I've always wanted one. I wonder if he's still in business...?