Diy guitar ebow

[marcbarker]

No you don't ever touch the string with it, 'cos it'll kill the note.

It could be a number of reasons, and multiply those by the opinions of forum posters you have dozens of wild goose chases down dead ends to look forward to.

There's no way of knowing without you doing some tests and gathering some clues.

If you monitor the amplifier output when the string vibrates, is there a decent sound signal there? (more than a volt AC)

 

[Mdkanz]

i just tested the output with a voltmeter and It actually had a constant 1.6VAC whenever the battery was connected. even when it wasn't near the strings.

 

[marcbarker]

Does your AC voltmeter respond to DC?

Is that really 1.6 VAC?

If it's really 1.6 VAC, maybe it's picking itself up through magnetic feild coupling.

 

[Mdkanz]

yes the volt meter i used was a digital one with a dial to choose what you want to measure.

 

[gabeNC]

I have a ebow and they don't really "change" the sound, it just keeps the string vibrating. The instruction manual says to use the neck pickup and turn the volume pot halfway down. The unit is very sensitive and it's pretty simple to simulate swell delays or bouncing chord formation.
The bottom of the case has these ridges that allows alignment of the target string, making is easier to keep the magnetic field (?) in close proximity of the string. Look up ebow on youtube, there are alot of people who play with them, Phil keaggy is a master of it.

I use it in conjunction with delay or my boomerang sampler. Adding layers and overdubbing synth sounds are pretty cool.

 

[marcbarker]

yes the volt meter i used was a digital one with a dial to choose what you want to measure.

Yes! but how do you know it's not responding to DC voltage and telling you that it's "AC"?

The only sure way of knowing is set it to AC and measure a battery.

If it really is AC there, it sounds like the ebow is self-oscillating, 'picking itself up' directly, rather than via a string.

 

[Mdkanz]

If it really is AC there, it sounds like the ebow is self-oscillating, 'picking itself up' directly, rather than via a string.

How could i fix that?

 

[audioguru]

The pickup coil needs to be connected to the circuit with shielded audio cable.

 

[marcbarker]

The pickup coil needs to be connected to the circuit with shielded audio cable.

I believe the pickup coil is already screened cable.

A possible cause of feedback, is via the magnetic flux directly coupling between pickup and 'output transormer". That could happen if they are too close to eachother.

There's no way of knowing for sure really until you do some experiments and gather more symptoms. We can all take guesses at what's wrong in the meantime!

Some thing you can try is to 1. reverse the phase of the 'output transformer'. 2 temporarily relocate the pickup coil to the amp speaker.

 

[charlieFarly]

Hi guys.

This all sounds very interesting. I'm an art student/musician. I want to build an ebow to oscilate a string for a sculpture I intend to make. I have little knowledge of electronic jargon. Could somebody please explain how to botch together an ebow? It doent matter about casing or anythng. I just want to familiarize my self with the technology and am willing to experiment. Using bits of old telephone sounds really interesting and is just the sort of thing I am into trying out! If someone could just give me some steps to follow to build an ebow that would be most helpful.

Cheers!

 

[HellHound]

Would headset speakers do? i used one 8 ohms coil and a 50 ohms one and i used a TDA2822M.But i got no results,altho i know the circuit works because when i put my ear next to the output speaker and tap the input one i cand hear the tap.

 

[cowboybob]

Welcome to ETO, HellHound!

Would headset speakers do? i used one 8 ohms coil and a 50 ohms one and i used a TDA2822M.But i got no results,altho i know the circuit works because when i put my ear next to the output speaker and tap the input one i cand hear the tap.

Did you use the speakers with their cones in place or just the coils (cones removed)? Since the ebow is an inductive device, the cones interfere with the function desired.

You might take note that the thread you're responding to is 5 years old.

 

[HellHound]

I actually thought of removing the cones for that reason,i just wanted to make sure first before I went to tare them down.And yes,i did noticed the threads date) thanks for the responce

 

[Tzenobite]

So, can i post something too? Thanks
I'm looking for a diy project for an ebow too, but since here's some people that actually had one built i have a question: since the ebow amplify and sustain a vibration "picked up" by the first coil, if the second coil is simply powered by the battery doesn't it make a magnetic field and then do vibrate the string when the two go near? I need that, for my dulcimer, something that i move near a standing still string and the string starts vibrating... Do i have to build an ebow or a simple powered coil may do the trick?
don't know if what i wrote make sense, i'm italian and my english isn't so good, sorry people

 

[audioguru]

A battery is not an amplifier. The pickup coil has a very low output level that needs to be amplified with an amplifier. If a string is not vibrating then the coils will do nothing. You must pluck the string to get it vibrating then one coil acts as a microphone that picks up its movements, its output is amplified and is used to drive the other coil that adds feedback to keep the string vibrating.

 

[Tzenobite]

sorry, now i see the point, the chip don't generate the signal... the input coil read the vibrating string and generate an amplitude moderate signal that the chip amplify and send to the output coil, then the output coil move the strings?
sorry for the dumb silly question from a total n00b, if i give to the chip input a fraction of the battery power the thing will works without the string vibration at the beginning? or it will works adding a chip to generate the frequency instead of the input coil?
i wanna know if it's possibile to give to the string a adjustable vibration despite the string own vibration (or not vibrations at all) and with a way to cut the vibration with a simple button, it will be useful for my needs also a "standard" ebow with a sort of kill button to get staccatos
thanks again!

 

[alec_t]

it will works adding a chip to generate the frequency instead of the input coil? i wanna know if it's possibile to give to the string a adjustable vibration despite the string own vibration (or not vibrations at all) and with a way to cut the vibration with a simple button

It should be possible to start string vibrations that way, but the string has a natural resonant frequency so the frequency generator would need to be tuned accordingly.

 

[Tzenobite]

thanks! there's a way to get the natural resonant frequency of the string? a magnetic pickup and an oscilloscope, maybe? what's happening if the coil give to the string a different frequency than the resonant one?

 

[Tzenobite]

(btw, great match today at the rwc, dragons )

 

[audioguru]

You cannot make a guitar string play a frequency that is different from its resonant frequency. You change its resonant frequency by changing the tightness or length of its string.
I don't know what sound is a "guitar elbow" and looking for an example in Google showed only elbow injuries on athletes.

If you turn up the gain of the amplifier then you can cause the elbow string to vibrate at its resonant frequency, similar to feedback howling from a microphone and a speaker.
"Sustain" on an electric guitar is also similar where the sound from the speaker is fed back to the string and the resonant sound goes around and around through the amplifier, the speaker and the air.