Hexaphonic Pickup Project

[Mike Sulzer]

Steve,

Speaking of hex fuzz, here is my latest six string fuzz electronics for in-guitar use with switches for combining two pickups.

May I suggest a lithium ion battery like the Variax has.

My application would accept a certain amount of string crosstalk. It's basically going to be a variation on the hex fuzz theme.

I'm trying to get this (youtube link) to handle chords better. I think if I used one channel of processing per string, and combined the signals as late as possible, it would help a lot.

[cycfi]

Mark, that's pretty much what I'm proposing to build, except I'm going to connect it to a Tesla coil instead of a regular amp. I'm already using what amounts to a fuzz and envelope follower circuit, but it takes the output of all 6 strings combined. I want to run one circuit per string. I can't decide whether to do it in analog or DSP.

I don't think you need DSP for that, Steve.

[cycfi]

Yep, that's what it was. it actually has quite a bit of wire on the coils, but it's 28 gauge wire. They are heavy pickups if you ever handled them.

What an odd beast! Thanks, David.

[Mike Sulzer]

I don't think you need DSP for that, Steve.

DSP is not be necessary for this, but it is certainly more flexible, allowing you to do things either difficult or impossible with analog. I like analog for going inside a guitar because I can make a very low power circuit that fits in a small space, but other than that, why would you want analog?

[cycfi]

DSP is not be necessary for this, but it is certainly more flexible, allowing you to do things either difficult or impossible with analog. I like analog for going inside a guitar because I can make a very low power circuit that fits in a small space, but other than that, why would you want analog?

Don't get me wrong, for my project (hex processing), I would need full DSP. I'm just replying to Steve's comment. An envelope follower and fuzz per string does not require DSP. Of course, perhaps Steve wants a lot more than that.

[Mike Sulzer]

Not necessary, yes. But you have better control over the characteristics of the distortion with DSP.

Don't get me wrong, for my project (hex processing), I would need full DSP. I'm just replying to Steve's comment. An envelope follower and fuzz per string does not require DSP. Of course, perhaps Steve wants a lot more than that.

[cycfi]

Not necessary, yes. But you have better control over the characteristics of the distortion with DSP.

Agreed 100% and you can have a *lot* more beyond fuzz and envelope following.

[Steve Conner]

It certainly doesn't need DSP. If I wanted to get it working right now, I'd use 6 copies of my current circuit. But I was thinking along similar lines to cycfi, that it would be cool to have a DSP guitar for other reasons.

[cycfi]

May I suggest a lithium ion battery like the Variax has.

That is fine. But with an optical connection only, how do you charge it? D.C. jack? Port powered solutions like USB don't have this problem. And it is most certainly annoying when the battery runs out in the middle of a gig or recording and swapping out the battery is out of the question.

I'm conflicted. Support both USB and ADAT perhaps? :-/

[cycfi]

Let it breathe (part 2): More Frequency Analysis

Let it breathe (part 2): More Frequency Analysis

Last time we did some (very rough) preliminary tests comparing an early version of the hex pickup with a Fender Stratocaster and a Gibson Les Paul. The initial test was done using a 2000 turns AWG 42 coil and the cheapo TL072 Op Amp in differential configuration. The goal basically was to see the frequency spectrum of lower impedance coils side by side with that of the single-coil Strat and Les Paul humbucker pickups. Here we will continue with the tests, this time focusing only on the Hex pickup installed on a Strat while continually improving on various aspects of the pickup design.

Tell me what you think.

[soundguruman]

Let it breathe (part 2): More Frequency Analysis

Last time we did some (very rough) preliminary tests comparing an early version of the hex pickup with a Fender Stratocaster and a Gibson Les Paul. The initial test was done using a 2000 turns AWG 42 coil and the cheapo TL072 Op Amp in differential configuration. The goal basically was to see the frequency spectrum of lower impedance coils side by side with that of the single-coil Strat and Les Paul humbucker pickups. Here we will continue with the tests, this time focusing only on the Hex pickup installed on a Strat while continually improving on various aspects of the pickup design.

Tell me what you think.

[ATTACH=CONFIG]23118[/ATTACH]

The fundamental design of the PU needs to be re- assesed. The design is just another conventional PU, split into six outputs. Until this is changed, there will be little or no improvements made.
That's the stumbling block to all guitar interfaces.

[cycfi]

I guess that depends on what you mean by "improvements". To be honest I don't even understand the essence of your previous post in this thread and why you never bothered to explain what you meant. It seems we are not in the same page.

[Steve Conner]

I don't think I ever understood the essence of any of Soundguruman's posts.

Yes, this design will suffer from bleed between strings. The Roland pickup went as close to the bridge as possible to mitigate it, as the string vibration is smaller there.

[Hugh Evans]

He could be confused by your logic behind choosing hexaphonic coils. It might not make sense to most people until they see what they can do in combination with a DSP. Since we are working together it should be easy enough for someone to run a traditional style low-z pickup through your DSP system, it should be easy enough. I know I look forward to trying it out.

[cycfi]

Ok... so we are currently using single-coils in floating differential mode. The coils are connected to the + and - inputs of the differential amplifier without any direct path to ground. This configuration is inherently noise canceling. Should we be using double coils in humbucking configuration instead to get even better noise cancellation?

Here, we talk about the limitations of passive humbuckers and propose possible alternatives such as the Bifilar Coil winding. Read the rest here: Singles or Doubles?. As always, I'd love to hear your thoughts.