ikay

According to this thread the correct size is a rather tiny 0.05" )

If they're out of phase you'll get a drop in output when both pickups are full on. What's the volume like with just the neck pickup or just the bridge pickup? Having a low output doesn't necessarily indicate a problem (unless it's stupidly low). If you can adjust the input gain of your amp to compensate for the lower output and get enough volume then it's probably nothing to worry about. What model of bass BTW?

Nice looking bass. The pot codes may help with dating. Some other dating tips here - https://www.beatlebassdealer.com/dating-hofner-serial-numbers.htm

There's a black Vista Musicmaster for sale here - https://reverb.com/uk/item/20655705-squier-vista-series-musicmaster-bass-black-1997? Unfortunately it's in Australia!

Yes, it's a Bronco with a replica Musicmaster decal from https://luthierdecals.com/

I love my Bronco. It's well put together and with a few mods and a bit of fettling it plays and sounds way above it's price point. Mine has a Sentell Big Sis pickup (https://www.sentellpickups.net/bass.html), Hipshot Vintage bridge and Hipshot 3/8 Ultralites. Fabulous little bass!

I love Fralins. Have an early Lakland Skyline JO from 2002 when Fralins were fitted as standard. Fabulous bass. I notice that your box is marked +5% overwound so yours may sound a little beefier and darker than a regular set.

The chart is generic for passive tone. I think the frequencies shown are actually for a Jazz but the same principle applies to P and any other passive bass with a regularly wired passive tone control. The bump in the low mids when tone is fully down kicks in if one end of the tone cap is wired to ground. Some basses have a small resistor between that end of the cap and ground in which case you don't get the bump . Some G&Ls are wired that way.

We're almost neighbours lol!

Generally speaking yes, a passive tone control acts as a low pass filter and cuts higher frequencies leaving the lower frequencies intact. The chart below shows frequency response for a passive tone control at various tone control positions from T10 (fully up) to T0 (fully down). A slight frequency hump occurs when the tone is fully down.

Sounds like a dodgy piezo element on the B. I'd contact Esh for a replacement http://esh-bass.com/contact/

The 47k resistor should be on the output of the preamp (ie. on the side of the switch that connects to the output jack). The 470k resistor on the preamp input side of the switch should be yellow/purple/yellow, does that match what you can see?

This online resistor code gizmo gives a value of 47k - https://www.allaboutcircuits.com/tools/resistor-color-code-calculator/

I don't think that replacing the existing resistors with different values would make much difference. Can you try an experiment and test to see if the active/passive switch still pops with both pickups in the 'off' position? Then test again with both pups in the parallel and series positions - is the pop louder in the series position?

According to this diagram the EQ ON/OFF switch already has a 470k resistor across the input and a 47k resistor across the output which should prevent popping ...

Adding a 1Mohm resistor between signal and ground on the switch seems to be a common fix. Can you post a pic (or wiring diagram) of your active/passive switch?

Hi B.Flat, I'm afraid this is a bit beyond my tech abilities. I had a similar problem with a BB1100 which made an annoying pop when switching from passive to active. A common issue with that particular bass and apparently something to do with how the battery is wired and/or floating output signals or what have you! As a work around I just turned down the volume on the bass before switching which did the job but I never fixed the issue itself. There's a short thread about it below. I don't understand why adding your PUP switches would have any affect on the active/passive switch though, that is a bit wierd. Hopefully someone will be along soon who knows more than me (not too hard lol)!

Ah OK, then yes, your ON/OFF/ON DPDT switches will do the job exactly as you say with the middle position being off. Make sure you check the pin connections before wiring as not all DPDT switches are the same.