Straight thru z-coil

Mon Jul 11, 2022 5:29 am

I got curious about how a z-coil would sound wired straight to the output jack.
The question in my mind is whether that would increase dynamic and tonal range (I'm a classical guitarist originally, so I like to get as much from fingers and strings as possible) or whether the nature of a pickup has inherent limits this way.

The plan is to try wiring the pickup to the jack via a switch so I can compare straight through vs through the tone stack. I'll post up with the results!

Re: Straight thru z-coil

Sun Jul 24, 2022 9:10 am

The Z Coil's resistance and inductance values are publised somewhere on this website. An electrical model of the pickup is an AC signal source in series with that resistance and inductance. The inductance directly impacts what treble makes it out of your instrument to your amplifier, this impact increases with the amount of current that the pickup has to source. Your amplifier is a load on your pickup, as are the volume and tone controls of your guitar. So wiring straight through will reduce that current load and increase your treble.

The question is how much gain will you get? I haven't done a calculation on this which would predict what amount of change you'd get. The bottom line is if the calc doesn't show at least a 3 db change you won't hear the difference. Several folks do report hearing a change so it may be a worthwhile effort, but the results from a specific pickup may not apply to your Z Coil due to differences in resistance and inductance.

If you want to get the maximum signal out of your guitar after bypassing those controls I'd suggest a buffer pedal, I'd put it as electrically close to your guitar as is possible. The buffer pedal preserves all your signal and unloads your guitar's pickup so almost 0 current flows. A decent buffer will have an almost infinite load impedance to the guitar and an almost 0 source impedance as a source to your amplifier.

But

A buffer amp will also remove the impacts of loading on your guitar from your amp and effects that have been present since the beginning of electric guitars and is what our guitars and amplifiers are "supposed to sound like". The loading on the pickups by the amp and cable attentuate the output signal of your guitar in a variable way based on what the frequencies are coming out of your pickup.

A buffer amp will result in your guitar being "hi fi" sounding. This is similar to the sound a Commanche VI makes, as more and more 1/2 coils are switched on the resistance and inductance of the sum of those pickups drops and becomes a low impedance source.

I think the question then becomes what am I going to do with my guitar? If you have a bunch of effects get a buffer pedal and experiment with where in your effects chain it should be. If you're going straight into the amplifier a buffer pedal may help or hurt your sound. The same can be said about wiring your Z Coil straight to the guitars output jack, it may help or hurt your sound.

I found years ago that my Park 75 1/2 stack (with baby blue speaker cloth and Ipswitch green backs) had a treble compensation capacitor in the preamp circuit (before the tone stack) that made it unusable for Fender single coils. This capacitor was incorporated into the design to provide some treble boost for humbucking guitars (this was a 1971 Park 75). Bypassing the cap removed that compensation and the amp sounded great with my Tele ever after. (I sold that Park 75 and speaker cabinet before retiring and prior to the sale I removed the bypass and any tell tale solder from the amp circuitry to return it to its original state). You may find on your Z Coil that an idea that's really great for a specific guitar/amplifier system doesn't work out for your set up.

The Z Coil has a lower resistance and inducatance than a typical Strat pickup so Leo has already taken some action to preserve highs from disappearing in the pickups internal resistance and inductance. The Z Coil's sound is overwhelming driven by the strong (IMO too strong) ceramic magnet, the wide magnetic field captures more bass content with no treble enhancement vs. a more focused magnetic field. I've written a bit about this in my Z Coil Project Page posts. I think the treble gains from bypassing the controls will be small and perhaps imperceptible.

You won't know until you try it. I suggest you try the bypass and decide after listening to your setup for a while. It's going to cost you a set of strings, some solder and some wire. And maybe some time to put your guitar back to the origianl design if it doesn't turn out.

Unless someone has your exact setup and can give you feedback other experience isn't directly applicable. Even the impact of this mod on a standard Z Coil vs a Will Ray Z Coil will be different. Go for it and tell us how it went.

Re: Straight thru z-coil

Fri Jul 29, 2022 5:26 am

Thanks Rodney!
That's what I've found so far, there's "more" of everything, particularly treble (unsurprisingly), and the 2.5 kHz peak is more prominent.
Great for cutting through a mix, but more difficult to get "sweeter" sounds. And of course the bridge position is a bit thin sounding to begin with (not a big fan of bridge only in general).
I'm comparing a standard Z coil in the project guitar to a WR in the tribute Comanche, so it's not apples to apples, but I've got similar strings on each now and I'll play with pickup heights and report back :)

Re: Straight thru z-coil

Fri Aug 19, 2022 4:52 pm

Here's progress so far, with circuit diagram for explanation:
https://photos.app.goo.gl/r5BivJc1ygPZwx3W7
(link rather than pic, sorry, cos Google Photos doesn't play nicely with BBCode

It's essentially a "blower" switch, but the results will be interesting to hear :)