How do you make an eBow?

October 4, 2005 5:55 PM

A friend wants to know: how does one make an eBow from scratch?
posted by Count Ziggurat to Media & Arts (11 answers total)

Best answer: Here's a schematic from Google image search.
posted by weapons-grade pandemonium at 6:04 PM on October 4, 2005

Wow, that's brilliant. I like it.
posted by RustyBrooks at 6:49 PM on October 4, 2005

Were you saying that the device was brilliant, or the schematic was? If the latter, I'm impressed by anyone who looks at a schematic and can tell what it does ...

And yeah, the eBow looks like a pretty cool invention.
posted by louigi at 7:01 PM on October 4, 2005

Better buy a few LM386's; they pop easily.
posted by ZenMasterThis at 7:08 PM on October 4, 2005

Oh, and a socket for the LM386 wouldn't be a bad idea. You'll thank me later.
posted by ZenMasterThis at 7:09 PM on October 4, 2005

A magnet glued to the end of a vibrator. Seriously.
posted by sourwookie at 11:30 PM on October 4, 2005

Follow-up question: I already have an eBow, but how much will it cost Count Ziggurat to make his own (parts & tools, inclusive)?
posted by mds35 at 6:52 AM on October 5, 2005

I already have an ebow, and I like it. I'm not saying the schematic itself is brilliant, but the idea behind it is. I'll try to summarize. The triangle in the middle is an "operational amplifier", which is capable of doing a lot of stuff, but in general you can think of it as amplifying the input signal. The input in this case seems to come from the telephone pickup. The output is a transformer, which is something like a guitar pickup to begin with.

Electric guitars work because you have a ferrous metal (the strings) moving through an electromagnetic field (generated by the pickups) which induces a current in the pickups. You can do the reverse (make the strings move) by running current through the pickups. So, the ebow seems to be taking input from the strings, amplifying it, and inducing the strings to move with the amplified signal. It's feeding the output of the strings back to themselves which tends to reinforce whatever they were doing (although often in somewhat mystifying ways).
posted by RustyBrooks at 11:34 AM on October 5, 2005

A magnet glued to the end of a vibrator would be useless, because it always vibrates at the same frequency. The reason the ebow works is because it creates vibrations that match what the strings are already doing, so the frequency will be right to get reinforcing feedback.

Something I've tried a few times which can be pretty interesting (sorry for the derail but it reminds me of it).

Take a guitar, and split the signal. Have one of the signals going to another room where you have an amp set up to a cleanish tone, and you're miking the amp. Have the other signal go into the room with you, with a heavily distorted, fairly loud amp. Have this amp close to where you're playing guitar. By turning into the amp (facing it), you can get a LOT of feedback. But you're recording off the clean amp... so you get this incredible singing quality out of it. Hard to explain, I'll have to see if I can dredge up a sample. I don't perform live but I always wondered if I could do the same thing by having the distorted amp going to a very small speaker that I could hold in my hand or have on a mic stand or something, and just bring it close to the guitar when I wanted the effect.
posted by RustyBrooks at 11:37 AM on October 5, 2005

I've done my share of hobbiest electronics, but the directions concerning the output transformer confuse me. Can anyone elaborate on the "I core metal removed and the E core aligned..." bit?

I would attempt building this if I knew what to expect with modifying the transformer.
posted by monsta coty scott at 6:23 PM on October 6, 2005

RustyBrooks's alternative is a great idea to try when recording; I would also like to add that you can achieve the same effect using modeling software such as AmpFarm or Guitar Rig (among others). That is, if you have an audio interface / sound card that has a reasonably low latency (mine is 8 ms). You put the Guitar Rig as an insert to your input channel, recording only the dry pre-insert signal. You still need something other than headphones to monitor and create feedback with of course; any good old guitar amp will do, or your hi-fi / monitor speakers (I wrecked a tweeter on my hi-fi that way once).
posted by goodnewsfortheinsane at 5:08 PM on October 13, 2005