Ebow Exposé Part IV - RESURRECTED!

[soggybag]

soggybag : https://www.sustainiac.com/install.htm

lots of different wiring types..depending on guitar pups etc.....

This Sustainiac is from early 2000s. The new ones have a different connector. I have on a piece of paper somewhere.

There are a few ways to wire it. I used a push-pull pot to turn the sustainer on. Another push-pull pot for the mix mode.

It works well. Mine has an issue where there is a little "grit" in the clean sound when the sustainer is off. I asked about and got a couple conflicting answers, no solutions. I got the impression it wasn't "fixable". Otherwise it works.

[Rob Strand]

It works well. Mine has an issue where there is a little "grit" in the clean sound when the sustainer is off. I asked about and got a couple conflicting answers, no solutions. I got the impression it wasn't "fixable". Otherwise it works.

If you probe the outputs of the comparator and the opamp you might find one of those is still enabled and clipping.   The patents show muting circuits but perhaps the muting circuit is too far up the signal chain and the stuff before is clipping.   Just how the grit gets into the clean circuits is up for grabs: power, Vref, or across one of the JFET switches.  For that matter it could be the JFET switch itself leaking through because of a strong signal feeding it.

[soggybag]

It's an amazing product. I think what I have the Sustainiac stealth. The newer stealth pro is improved.

Look carefully near the two smaller light blue electrolytic caps and you'll see a little pile of surface mount resistors. Looks like there was an error and the needed to jump something or make a voltage divider?

[Rob Strand]

Look carefully near the two smaller light blue electrolytic caps and you'll see a little pile of surface mount resistors. Looks like there was an error and the needed to jump something or make a voltage divider?

Yes, I noticed the mod.   I can't quite work out what it is doing.  I meant to come back to it but I wasn't able to extract any more info.

The circuit is like:

cap -->  resistor 1 (10k) --> mod resistor 2 (10k)  --> resistor 3 (10k)  --> pin 9 (input of 40106)

The 40106 is a CMOS hex Schmitt inverter, a digital part.

There's a tap between resistors 1 and 2 1 which goes to an unloaded SMD part, cap or resistor who knows.  The other side of the unloaded part connects to the first cap in the above chain of parts.  There must be some other tracks from that chain of parts.

As a wild guess it looks like some sort of signal detection circuit and the R's and C set a time constant of filter.    It could equally be inverters used for the signal switching!   The purpose of adding mod resistor 2 is still a mystery.

[deadastronaut]

calling mr marossy...

hi paul, do you have the dimensions of the ebow?

i have a cheapo 3d printer and would like to knock up an ebow...

not a direct copy. just a crude version ,but i just need the base plate dimensions really....

the battery box will be at an angle, for a more ergonomic design, instead of hooking your hand to be parallel with the strings. etc...which bugged me when i owned one....

cheers in advance....

[Paul Marossy]

calling mr marossy...

hi paul, do you have the dimensions of the ebow?

i have a cheapo 3d printer and would like to knock up an ebow...

not a direct copy. just a crude version ,but i just need the base plate dimensions really....

the battery box will be at an angle, for a more ergonomic design, instead of hooking your hand to be parallel with the strings. etc...which bugged me when i owned one....

cheers in advance....

I was thinking not long ago that a DIY Ebow is so much more in the realm of possible these days with 3D printers being so ubiquitous these days.
I have a link to PDF file derived from my AutoCAD DWG that is actual size at my website. You can get it here: http://www.diyguitarist.net/PDF_Files/EBOW%20Data.pdf

[deadastronaut]

brilliant, cheers man your a star.....

yeah im new to 3d printing, but its definitely got a lot of possibilities....

i,ll crack on.  nice one. 

[AngelLaHash]

This is how i am reading the circuit from the PCB board

which i think when in the REG stage will change things, that what is in the Spice Diagrames from the Videos (also notice a 33nF and 68nF towards the end so summing to be 100nF)

[AngelLaHash]

https://3dwarehouse.sketchup.com/model/5bbeefa3-b968-4762-859d-7b0321f576f7/ebow-simil?hl=en

if anyone can cut it so that only the one with the lid detached is being printed would be dam cool

well i managed to split it down but the BASE (bit that runs on the strings) is
2.57 (Length) x 1.26 (width) x 0.97 (Hight)

guy who measured it has it down as
48.36mm (Length) x 34.85mm (Width)

So length is a ratio of 18.81712:1 and Width is 27.65873:1
If it was in INCHS so that 2.57 (65.278mm) and 1.26 (30.004mm)
So Length is a Ratio of 0.74083152:1 and 0.92183475536:1

[amptramp]

There is nothing new under the sun.  There were more types of programmable instruments than a player piano - this one combines piano and violin and was made in the 1912 time frame.  It was installed in bars as a precursor to the Seebeck jukeboxes that were seen in diners in the 1950's and 1960's.  You insert a nickel in the coin slot and the programmed roll determines what notes will be hit.

It had the original sustain: there is a polished motor housing to the right of the violin that has a long shaft going to the left where it ends in a little white fabric roller above the strings where the bow would be placed.  Additional solenoids select the string.  The rotating part is brought down into contact with the string for a sustain that continues at the same amplitude as long as the note is played.  The big polished housing behind and above the violin neck has solenoids that push down on the strings at the appropriate position to sound the correct note.



There were lots of competing players of this type.  This one has a xylophone, a triangle and a drum:




My choice for a sustain would be the vibrating wire oscillator shown in the article starting on page 51 here:

https://worldradiohistory.com/Archive-Radio-Electronics/60s/1968/Radio-Electronics-1968-05.pdf