Hexophonic Pickup Feasibility

[Lizardhands]

Can anyone help me with the feasibility of a wiring system please.

I am in the process of commissioning an 8-string guitar of a similar fashion to the Charlie Hunter Novax guitar (but with different tuning/scales etc). I have found someone who is able to make me a hexophonic 8 string pickup which I'd like to combine with a normal p-bass pup and three outputs. I'd ideally like to have the hex pickup send all 8 strings blended to the mono guitar output, with the option to cut out the lower strings if a jack is connected to the bass output. I'd guess something like a switch jack would be needed.

In addition, I'd like to be able to send all 8 strings separately out via something like the 13-pin guitar synth plug. I have no intention or need to do synth/midi work, but this seems like the most available and accessible cable solution, and from there I would be able to make a breakout box to split the 13-pin into 8 jacks. With 13 pins, I'd guess I could have a signal from each string, and then a common ground with pins to spare; would this work? or do I need separate ground signals for each string?

So I would hopefully have three output options (only one at a time) 1) hexophonic mono out 2) hexophonic mono and bass mono 3) split strings via 13-pin.

Is this feasible? or even possible? I'd like to work this all out and spec the electronics before approaching the luthier.

[Robert_the_damned]

Well I'm certain that the first part is feasible, you could defenatly do what you wanted with the bass jack switching the low strings. Having that and each string giving a sepearate output though isn't going to be so easy, you'd probably have to go into having some op-amp buffers in there to do that. Though at least if you're running it down to a box you could have the power comming in on the cable. Yes I'd say all of that was possible it just depends on how complicated you want to make things.

and surely an 8 string pickup with individual elements is an Octophonic pickup?

[Lizardhands]

Thanks for the reply, and yeah, I guess it would be an octaphonic pickup.

So I'd need some form of preamp in the guitar, which I'd guess could be done (fairly easily). There are a couple of ICs which have 4 op-amps in them, so I suppose I could run two of those together in simple circuit. Stuff like the Graph Tech preamp board seem to be along a similar line, but for 6 in/out.

Damn me and my complicated needs...well, lets face it: wants.

[erikbojerik]

Robert is right on - the pickup outputs will be too weak to send down the long 13-pin cable without some kind of preamp.

[billm90]

if you dont want to use midi, then dont go that route. it is expensive. The ghost graph tech system was something I was considering, till I saw the $500.00+ price tag.

Take a look at the chapman stick site. this should have an 8 string midi hexophonic pickup option you might be able to do some research on.

as for breaking down you outputs.

Maybe I am missing your point... wouldn't it be easier to have switch options on the bass to do the bass pickup, and 8 octophonic pickup switching?

I know switches can seem like a lot, but here it an idea.

what I have done.

I built several of my own DIY piezo pickups. I put one on each string. (this is a pain in the ass)

I ran each of those 6 piezo leads into 2 mini dip switch that has 8 switches.

I have stereo outputs on the guitar.

I can shut down any string(s) on the left or right channel.

[i can put 1,3,5 on the left, 2,4,6 on the right or any combo you can think up]

add a mini toggle or 2 to add or remove the original bass pickups. 2 if you wish to combine that into the stereo field.

I thought of doing this method when I read on some yamaha acoustic that had an option for stereo string field. ever since I wanted this option, so I put it on a junker and tested it out. it works. I have built 3 DIY piezo guitars (into electric guitars) and some pickup the other strings that are off, but my wood bridge does not pickup the dead strings.

http://im1.shutterfly.com/media/47b7d736b3...3D550/ry%3D400/

this is the first bridge pickup I built as a test. it loos bad, but actually sounds the best.

http://im1.shutterfly.com/media/47b7d736b3...3D550/ry%3D400/

this is the 2 dip switches and the mess of wirring that went into a copy SG POS someone have me.

I guess the point I am trying to make, instead of going to the expensive midi solution for sake of cable ease. why not make the guitar do the work via switches, and hopefully only need a stereo cable if you wish to shut down strings?

Edited January 6, 2009 by billm90

[billm90]

I just looked up the chapman stick.

I guess I lied. no 8 string pickup for midi.

I could of sworn I seen it somewhere.

Anyhow. how and what is your octophonic pickup going to made out of?

individual coiled pickups? where would they be mounted?

[Ripthorn]

All of it is possible, but I think it is funny that with all these options we are worrying about the buffer. It most definitely is necessary, but if you are doing all the rest of this, putting in a buffer is nothing. I second the suggestion for switches, however. I would say put in a rotary switch perhaps that will give you bass magnetics, bass mags and octo, octo bass and octo full on a 1/4" jack and then also have the 13-pin jack going on that is completely seperate. You could do all kinds of fun stuff, though I think if I had the thing I would probably die before I ever got through all the combinations. Anyway, I say go for it and see what happens.

[Lizardhands]

Thanks for all of your replies, it's cool to get different views on this.

Re. the switches, I'm very much a fan of minimal knobs/dials/buttons on instruments. While dip switches would give me ultimate flexibility, it's not really what I'm looking for, having two jacks is my ideal situation. Basically, I want to be able to gig or play through a single channel amp with one simple cable and get a mono sum of the whole string set. If I have my bass amp with me or a suitable pa, I'd like to split the signal so that just the top 5 strings go to one amp from the main pickup, and the bass pickup sends out the bass strings via the second plug. That way I can have a stacked tone/volume pot for each pickup and be done with it. I'd presume I could use those circuit breaker cables and quickly switch between full and split output just by killing the bass cable.

The idea behind the individual string output boils down to my academic research. I'm working around interactive music and spacial acoustics, e.g. surround sound interacting with other arts like dance, drama etc. I don't need to have that kind of input for everyday gigging/teaching, but I'd like to have the capacity.

Thanks again for your comments, they're helping me alot.

[billm90]

what ever you end up doing, I would like to see the final out come. Keep us posted.

[dugg]

I recently met an older (than me, I'm 52) guitar tech in my SoCal neighborhood who goes by the nickname Docfret. He is personal friends with Bill Lawrence. He was telling me about working on such a setup for, I think, Carl Thompson, the builder of basses. His story was that he had some round coils, like bobbins, that were originally solenoids or something, lying around. He took rod magnets, like those in SC pickups and pressed them into the center of the coil and viola,...er voila. One thing he said was, in his original design had trimpots for seperate coil balance, but that he discovered in subsequent designs that moving the magnet up and down in the coil did a better job of balancing the volumes, so he later eliminated the trimpots. I have docfrets card around here somewhere....grr, I remember that his e-mail was docfret@yahoo.com He's a very approachable and friendly dude, he actually started the conversation with us when he overheard us talking. If you contact him, just say the guitar builders that met him in the bagle shop referred you. He'll remember us, it was only three weeks ago. I'd e-mail him if your serious about making this pickup.