Help me help myself ROCK OUT

August 2, 2007 6:54 AM

Follow-up-on-somebody-elses-post (filter): Okay, so I'd like to make an eBow from scratch. Here's the schematic available. Can you help out?

I can read the schematic fairly well, but I'll need to google for some of the symbols. The big question is the part about the output transformer: I have no idea what this means:

use small output transformer, with all I core metal removed and E core elements aligned.

You lost me at "transformer."

Okay, so if anyone can clarify this a bit (enumerating parts / connections would be totally awesome, if you can). That would be great.

Oh, and as far as soldering / that sort of stuff, I think I'm set.

posted by tmcw to technology (10 comments total)

Oh, and I've found the original page for that schematic: unfortunately, it's in dutch. Any idea what the box with "10" next to it is?
posted by tmcw at 7:27 AM on August 2, 2007

The element with a "10" next to it is a 10 ohm resistor.

I'm not sure what they mean about the output transformer...

* LM386 - This is a common Op Amp, which is a simple integrated amplifier.

* The small triangles with a bar at one end are diodes - they make current flow in one direction only

* The parallel bars are capacitors. The ones with one side fatter than the other are probably polarized (they have a positive and negative side)

* I think you need more information, particularly on the construction of this (where does the input pickup and output transformer go?

I have an ebow around, maybe I'll disassemble it and take a look...
posted by RustyBrooks at 7:38 AM on August 2, 2007

I did a little searching/reading online and the output transformer is probably a guitar pickup modified in some way. It's not clear to me how, though.

Some guys have made an ebow-like thing that actually just mounts in a pickup slot, and you turn it on to get sustain/harmonics. Not *quite* the same thing but similar.

Until now I didn't even remember posting in the previous thread.
posted by RustyBrooks at 7:49 AM on August 2, 2007

Rusty, are you talking about the Sustainiac?
posted by doctor_negative at 7:58 AM on August 2, 2007

Actually I was talking about the PG Sustainer but it looks like something similar. Some nice sounds on that page.
posted by RustyBrooks at 8:00 AM on August 2, 2007

Yeah, I'm looking to do an eBow-style contraption. No waay I'm making more holes in my Tele.
posted by tmcw at 8:15 AM on August 2, 2007

Better translation here (of the Dutch Flemish page)
posted by tmcw at 8:26 AM on August 2, 2007

And photos of one taken apart.
posted by tmcw at 8:29 AM on August 2, 2007

The transformers are key here, and are likely to be a deal breaker. They are designed specifically for the ebow, so you won't be able to use anything off the shelf, and to make one you'll need to know some difficult specifics: physical dimensions, wire diameter, core material, number of turns, etc. Then you'll have to make sure you end up with the right resistance and inductance at the end. Once you get the transformers made, you then have to figure out how to properly position them, once again you'll need some detailed specs.

I considered doing this myself a little while ago, and decided to just buy one because making one would involve a lot of time, not save a whole lot of money, and may not even work at the end .

If you still want to DIY this sort of thing, the Project Guitar forums will teach you how to make a sustainer, which is a lot more forgiving (even a crappy coil will work with a big enough amplifier, at least until it burns up :) Tons of fun there!
posted by waxboy at 9:27 AM on August 2, 2007

Hmm, okay, I guess you're right. I'll start on a compressor instead? Orange squeezer it is.
posted by tmcw at 10:19 AM on August 2, 2007