The whole thing was brush painted. I mixed Phalo blue acrylic paint with the Cabothane clear to create a transparent blue fade on the back, a bit like old blue jearns:
Similar on the headstock:
The back of the headstock and neck are done with Tung Oil; feels nice.
Hi Tony - I'm about to use that wiring diagram. Its just the solder on the bent looking tabs on the 2 volume pots that is missing isn't it? I saw that it is shown as soldered in some different diagrams but not for this one, so that was confusing me.
After attaching the vacant tabs on the volume pots to the back of the pots with a short length of wire (earthing them), the guitar seems to have these functions:
- switch up or down; either volume knob adjusts guitar output
- switch in middle; each volume knob adjusts each pickup
- bridge tone knob, cuts some treble
- neck tone knob, no noticeable effect
Compared to a 4-knob bass I have, it seems a superior setup to have bass + treble tone knobs (different value capacitors, wired in series), one volume knob, and a fader to swap/mix the pickups. The switch is then free - it could be a coil-tap switch if the pickups allowed it. Maybe later.
From your description, there seems to be a wiring issue, probably related to the pickup selector switch, With the switch up or down, the each volume pot should only adjust the volume of its respective pickup. In the middle position, you'll get a blend of the pickups in parallel, so the volumes will still have an effect and adjust the overall tone as well as the volume.
The tone controls should be effective and dial out most of the treble and mids from each pickup. If there's a switch or switch wiring issue, than that could be a possible reason for one control not being very effective. The neck tone should work, so check that the capacitor leg that's not soldered to the back of the pot isn't touching the back of the pot.
If you can post a pic of the wiring harness, then we may be able to diagnose some issues. It does mean taking the harness out of the guitar, but it obviously isn't right so needs sorting. It may be that a wire has broken during its insertion into the guitar. It does happen.
The problem with a blend pot instead of a 3-way switch is that with humbuckers (as opposed to single coils), with the available maximum blend pot track resistance being 500k, the effective signal resistance to ground drops off so that you lose a lot of treble and the pickups sound very dull.
I'm having this very issue with my current Jazz Bass build where I'm fitting SD NY4 humbuckers (effectively two JB pickups in one unit). I'm having to fit an active buffer circuit to help mitigate this.
The normal nominal single coil volume pot resistance is 250k, and for humbuckers, 500k, though pots measuring on the higher side of those values are generally deemed to sound better.
Put in a blend pot and a master volume pot, and you end up with the output signal being connected to three resistances to ground in parallel. Even if all three resistances are 500k, the resulting equivalent resistance is 1/3 of that, so 166k. You'll loose a significant amount of treble as a result. Making the volume pot 1meg, you still only get 200k, and only slightly less treble loss. Even with the blend pot fully one way or the other, the output signal resistance path to ground remains the same.
This is the basic control circuit:
On single coils on a bass, this is less of an issue as this is closer to the nominal ideal 250k, and JB pickups are used to being heard with less treble than they can actually provide due to the standard circuit designs used.
But on a guitar with two passive humbuckers, the humbucking sound will be very disappointing indeed (unless you just play jazz with a very bassy tone). You could do it with active pickups e.g. EMGs, where the low output impedance of the active circuit isn't loaded by the lower resistance ground. But then you need a battery, which isn't the easiest of things to fit on a 335-style guitar.
Last edited by Simon Barden; 19-10-2021 at 06:11 PM.
Quick response; I have 2 passive Wilkinson humbuckers in a bass with the fade control, and it rocks! Very high output, bright sound that works with slap, fingers or pick. I guess my settings are close to the 10, so pot resistance is near 0. Even so, I don't think your logic on cutting treble is correct; turning the pot to increase resistance will reduce the current / volume, but not affect the frequencies of the signal.
Pic below during installation of the coil-split switches. Bit of chiselling was required to cram those massive pickups into the cheap-ass Haze bass.
On the ES-1S, I think is the capacitor value that cuts frequencies above the bassy range coming out of the neck pickup, so the difference is barely noticeable. Going for a higher value capacitor would probably sort it, though I'd change the wiring to a bass + treble control affecting both pickups output, rather than 1 tone each.
You're right though, the way my volume knobs are working is defective. Somehow they're being switched into series, possibly through the earth. I'll get it sorted later.
It's not the pot position, it's the basic way the pots are connected that affects the sound with the volume full up. The pickups have impedance, inductance and a small amount of capacitance. In conjunction with the pickup pot resistance to ground, the amp input impedance and the guitar lead capacitance, they form a resonant low-pass filter. The higher the resistance path to ground, the higher the filter peak frequency is. The lower the resistance value, the lower the filter peak is and the more treble frequencies you lose.
Passive volume controls do affect the frequency output of the signal as you turn the volume control down (especially if wired the 'modern' way with the tone pot connected to the volume pot input rather than output). Again, it's all to do with the resonant filter created by the controls. It's why people often fit treble bleed circuits across the volume controls, to mitigate against the volume loss.
But all this is with passive electronics and though your bass pickups may be passive, from what I can gather online, those Haze bases all look as if they have a battery compartment and an active preamp in them. And active preamps and tone controls are a totally different thing.
Also, those MM style pickups are normally wired in parallel, not series, so are naturally brighter wired that way compared to being wired in series.
Single coils generally have far less inductance than humbuckers, and whilst less inductance means less output, it also means a brighter sound as the resulting filter resonant peak is higher up the frequency scale, with more high frequencies being passes and the resonant peak itself boosting treble frequencies rather than mids.
Guitar humbuckers almost always prefer a higher pot resistance value. As a result, very powerful pickups with lots of winds can benefit from 1 meg pots instead of 500k, but even vintage style/output level humbuckers are generally preferred if the pot value is on the high side of the pots tolerance, in the 520-530k region for best performance for a 500k pot.
A higher value tone capacitor pot means the tone control knocks off even more treble. You need a smaller value capacitor if you want the tone control to roll off less treble. I generally use 0.015uF caps now, on both single coils and humbuckers, as I still get a useable sound (for me) with the tone control turned all the way down. But tone is a personal thing, and others still might find that too bright for them.
Last edited by Simon Barden; 20-10-2021 at 09:35 PM.
That top is a real stunner!Originally Posted by tonyquoll
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