Favourite wiring mods?

Hello all,

I've just ordered some Tonerider Alnico II humbuckers for my AG1. They come with the four wires, which got me thinking (and googling) wiring mods. Obviously, there's the potential to coil split the humbuckers using either one to two push/pull pots, but I was wondering what other wiring mods people have made and found useful.

I was contemplating an active boost circuit, but I'm not overly exciting about batteries running out, and I'm not sure I've really got the space in my control cavity. I'm also thinking about using my two tone pots as master bass and treble a la G&L PTB. Possibly also with a push/pull tone pot to bypass the tone circuit altogether.

What are your "go to" mods?

Cheers,

Jon

Series/Parallel for each pickups coils is usually the first I do

I once built a super strat with Armstrong muthabuckers ,a humbucker and a single, however as each "coil" was actually a separate humbucker I used a Freeway switch and could have between 1 and 6 coils working. Yea, it worked but I never used it. Now I keep it simple with coil splits at most, not keen on the out of phase sound, so I guess it depends on what you play and the sounds you like.. My current strat build has a push/push that gives "everything on" in positions 2 and 4.

I usually have a switch to go from series to single coil. I have mostly done basses, but for an SG type build, I might be tempted be this Peter Green-ish mod...

https://www.premierguitar.com/articl...ke-it-variable

My G&L bass has a PTB tone stack. Passive MFD pickups used on most G&L basses have lots of highs, and a ton of booty. I almost always have a little treble rolled off so that they are not harsh, and a little bass rolled off so they don't sound too boomy. It never occurred to me that you might need this on a guitar--or even on most basses. I have read, however that if you play with a lot of distortion this might be useful.

If you do the PTB mod like they do at G&L you'll need to find a source for a 1meg reverse audio (C) pot for the bass tone roll-off. If push comes to shove, when I did my mod, I got one directly from G&L.

Thanks all - I think I'll try both the split coil and parallel wiring and see which one sounds better to me.

I'm still thinking about doing the PTB mod, and I've found C1M pots at Element14.

A pair of inter-linked push/pulls (vol & tone) for each humbucker will give you all four options on each: series humbucker, parallel humbucker, inner coil, outer coil. It’s a good way to experiment with different combos to work out which sounds work for you.

Then, if needed, you can potentially tweak and simplify the layout to focus on the variations you like/use, ie. neck series/para and bridge series/inner coil etc.

Thanks WeirdBits, that sounds like what I need. Do you have a diagram I can follow? The closest I can find is a jimmy Page mod

This will hopefully have you covered:
Attachment 37520

It’s a layout using P-Rails with standard SD colours: black +, white/red, green -. The neck pickup has a little extra with capacitor switching: series humbucker & P90 uses a 0.015uF and it swaps to 0.022uF for the parallel humbucker & rail. If you don’t want cap switching just use the bridge pup configuration for the neck as well. Here’s the relevant post in my build thread.

If you need something more specific for your build, just ask.

Linear pots on the volume, Weirdy? Not normal. I’ve got one P-rail pickup on a guitar and that works just as expected with audio/log taper.

Yep, not normal... was experimenting with older style values, flatter curve pots etc. I actually forgot the B volumes were spec'd on that diagram, thanks for pointing it out. Jon, if you do go for something like this, stick with the standard 500KA push/pull pots for both volume and tone.

Quote:

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Originally Posted by Simon Barden

Linear pots on the volume, Weirdy? Not normal. I’ve got one P-rail pickup on a guitar and that works just as expected with audio/log taper.

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Some like linear pots on volume for a more consistent taper. Volume doesn't jump so much between 10 to 8 and then shelving below. Way more gradual which some people prefer. I like 500ka with a 220k resistor across the input and output lugs for a more gradual taper which turns out to be something between a log and linear taper.

Proper log pots should be smooth all the way down with no jumping between 8 and 10. On any pot there's normally a dead area between 10 and 9 where nothing happens and then the resestance starts to kick in, but you'd get that with a linear pot as well (just refer to the manufacturers resistance charts). But nothing is really done isolation in a guitar/amp combination and the perceived response can vary depending on how clean or driven the amp is - or how any pedals are set.

A linear pot shouldn't have a perceived consistent taper, as hearing is definitely logarithmic and to get a smooth reduction in heard output, you will need a log pot. Though there are different variations on a log slope as it depends what the starting value for the curve is. You can't start from zero so the design curve has to start from a small finite resistance value which can vary quite a bit, which is why you get so many possible pot curves available from people like CTS, with 5%, 10% and 20"% resistance (or your choice for custom orders) at the 50% position. That curve is normally then approximated with two linear responses, as very few log pots have true log responses (requiring laser-cut resistance tracks). So the audio response will vary depending on the selected log curve and how well the manufacturer can replicate it within the pot.

A linear one simply can't give anything like as smooth a volume response as a log one (based on physics/acoustics). But it may well do what a particular player wants in terms of speed of response to turning a knob, so it comes down to personal preference. A log taper should suit most people, but if linear does it for you, then that's fine.

Edit: Looking at the CTS curves again, for log curves, only the lower part of the curve is linear, the upper part is actually curved (though the curve isn't quite the curve you'd expect to see if it was a single curve and there is a bit of a compromise around the 50% position area).

There was a time that I played around a lot with pots, and found pretty much exactly what Simon is saying to be observable.

My sense is that with most of the pots that are common in guitars the "curve" is actually two or three straight lines with different slopes as in line "3"...

Attachment 37537

...I have heard this given as a reason that log pots are often not smooth, I am not sure how audible the difference is between an actual curve and an approximation of a curve.

As with everything audio, if you can it's generally best to test, and there is a lot to be said for trying different values. I now build all of my control stacks outside the guitar so that I can get a sense of how things sound before I have to "commit" and get everything wired in. It's why the tone cap on my recent Strat-style build is physically located in the under the jack plate. That way I could try several different ones with the pickups in place before committing. I am glad to have done this because the one I liked the best was different than what the mfg recommended. Same can go for pots. You may be happiest if you try both kinds of pots to see which you like best. It's an interesting experiment if nothing else.

I needed to draw this circuit out so I could understand it. Here it is in case it's useful for anyone else.

Attachment 37846