DPDT switch advice sought.

[B.Flat]

I wish to add series /paraiiei switching to my DiMarzio P+J set. I have a wiring diagram but the notes accompanying it say I require an ON/ON DPDT switch for each pu.

I have a couple of ON/OFF/ON DPDT switches in stock.  If I follow the diagram using these will I obtain the correct switching, albeit with the respective pu being switched out in the centre position.

Thanks in advance for any advice.

[ikay]

Series/parallel usually only requires a single ON/ON DPDT. One position leaves the pickups in standard parallel configuration, the other position switches them to run in series. Is this what you're trying to achieve or are you trying to do something else? I'm not sure why you need a switch for each pickup. Might be an idea to post the wiring diagram that you're using so others can take a look.

Edited March 19, 2019 by ikay

[B.Flat]

Hi iKay.

Sorry I assumed too much. I should have explained that the DiMarzios are four conductor hummbuckers, so the series parallel is between the two coils in each pu, hence the need for individual switches.

I hope that clarifies it.

What do you think ?

[itu]

With a rotary switch you need one hole less. 2 cents...

[ikay]

1 hour ago, B.Flat said:

... so the series parallel is between the two coils in each pu, hence the need for individual switches.

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.

Edited March 19, 2019 by ikay

[B.Flat]

Hi iKay.

I have fitted the DPDT switches and they are performing correctly. However I have noticed that the previously silent active/passive switch operates with a loud click/bang.

However the volume of this noise appears to vary from time to time, not from one p/u or tonal setting to another. A bit confusing, any ideas ? It is almost as if there is some kind of static build-up that triggers it, but I am sure I am probably wrong about that. !

You have responded to several of my other queries in the past and I would just like to say again that I am very grateful for your advice;

 

[ikay]

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)!

 

 

[itu]

It is  easiest to solve with a Mohm resistor to ground. Search engine helps here.

[ikay]

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?

[BassBunny]

Here's a set of Bartolini wiring diagrams where they use resistors to ground on their Active/Passive arrangement.

Bartolini XCTC.pdf

[B.Flat]

3 hours ago, ikay said:

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?

The IMohm resistor sounds like the solution, here is the wiring for the EQ switch.

BassBunnys diagrams also look very useful, I will try the Mohm resistor first

[ikay]

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 ...

[B.Flat]

Yes, well that is what I thought but my electronics knowledge is near zilch so I was not sure. These resistors are still in place and connected OK. Would you advise leaving them or replacing with the resistors with values as shown on BassBnnys diagram. Would the change of pickups  and their DC resistance have needed a change of these?

[ikay]

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?

Edited March 25, 2019 by ikay

[B.Flat]

iKay,  I must apologise for wasting your time ! I have solved the riddle. One of the resistors  on the A/P switch is faulty! However maybe you can decipher the colour code for me,  yellow purple orange green, either 47K or 470K

[ikay]

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

[ikay]

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?

[B.Flat]

Back again iKay !   47K, net search produced the answer, and I'm out of your hair now, thanks again for your respnses.

48 minutes ago, B.Flat said:

iKay,  I must apologise for wasting your time ! I have solved the riddle. One of the resistors  on the A/P switch is faulty! However maybe you can decipher the colour code for me,  yellow purple orange green, either 47K or 470K

 

[B.Flat]

Second apology in one minute, I had not seen your reply to the value query,  sorry.

[itu]

And your choice for tolerance is 5 % which is gold coded, not something funny like 0.5 %!

If you go to a shop or make an order, the resistors need to be metal film ones. They are nearly the same price but superior in quality compared to carbon sH*t.

https://www.mouser.co.uk/ProductDetail/KOA-Speer/MF1-4LCT52R473J?qs=91WPSIiQh9LK86gI2c0f1w%3D%3D

Edited March 25, 2019 by itu