HB1 Bass wiring

[Keyboarder]

I need to at the very least replace the volume pot on my 1988 HB1. It looks like a typical Precision bass configuration but with the addition of a toggle switch. Upon further investigation, it is not. First difference, PBass pickups are wired in series, the HB1's are wired in parallel. The HB1 has a toggle switch that flips the polarity of one pickup relative to the other. The PBass uses 250kΩ audio taper potentiometers for volume and tone with a .047uF cap. The HB1 appears to use a 900kΩ audio taper for volume and a 100kΩ for tone. There is not any notation on the pots or it is obscured by the solder. Does that seem right?

I am assuming the pickups are Schallers. If anyone has opinion and experience on this, I'd like to hear it. And recommended sources too. Cheers, B3

BassPickupWiring.pdf

[Keyboarder]

Thinking while eating lunch, that 900kΩ volume pot is probably toast demonstrated by the strange value, 900kΩ. Wonder what it should be.

[TalismanRich]

Ren Wall at Heritage could probably answer this one easily.   You might try dropping him an email, or giving him a  call.

PHONE:+1 (269) 385-5721
E-MAIL: support@heritageguitars.com

 

[PunkKitty]

Can you post a better picture of the bass so I can see what options it has? Thanks.

[Keyboarder]

Thank you TalismanRich. I'll also check in with Schaller. They still manufacture PBass PUPs, have wiring diagrams for their guitar PUPs and in a spreadsheet for the PBass PUPs meaning wiring them in both series and parallel. Attached PunkKitty. I assume you mean the wiring...

[PunkKitty]

Okay. Here is the wiring diagram for it. You can use 500k or 250k pots. It's up to you. 500k will sound a bit brighter. Unless Schaller pickups are strange, they should not be using 900k pots. I wouldn't even know where to find a 900k pot.

[PunkKitty]

According to their site, Schaller no longer offers a P bass pickup. Here is the info I could find.

https://www.schaller-electronic.com/hp246439/PickupFinder.htm

 

[PunkKitty]

Here are the wiring codes. A P Bass pickup is just a side by side humbucker.

http://www.stewmac.com/How-To/Online_Resources/Learn_About_Guitar_Pickups_and_Electronics_and_Wiring/Schaller_Humbucking_Pickups.html

[Keyboarder]

Thank you for the forensic work PK. I made a wrong assumption, that a twisted pair was the output (+/-) of one pickup. The Schaller wiring guide says otherwise, that grn/wht is one pickup and yel/brn is the second. While the wiring in my HB1 for the on/on DPDT mini-toggle does not conform to any of the configurations shown on the StewMac/Schaller diagram you referenced, chasing the signal flow through the switch says this is a series/parallel switch and not a polarity switch for one of the two pickups. I can confirm this with a DMM when I get to working on it. What I have not determined is the value for a replacement volume pot. The tone is 100kΩ. The current vol pot shows 900kΩ and there are dead spots on the trace, so it is shot. I'm inclined to use the StewMac PBass kit (2-250kΩ pots w/.047uf). I should also note which position I have generally preferred on the toggle, parallel or series. Thanks again.

[PunkKitty]

I would use 250k pots with a .047 cap. Heritage used some strange pot values in the past.