Tone pot left out….

[mybass]

Although I can design and build a bass, I go by the standard given schematics for the wiring. I’ve made a fretless bass with jazz pups (Delano) and wanted to leave out the tone pot, using a blend and a volume pot only and this bass is loud, pickups dropped a bit to compensate!  I opened up the control cavity and wired in a tone pot, trying first a .1 then a .47 capacitor and noticed  a bit of difference between them but I’m only using a combo in my workshop so I’m not really hearing the loudness of stage sound changes with these values. Then I left the tone pot in but didn’t add a capacitor and was surprised to still hear tonal change when the pot is turned, )the left lug is unattached but the pot is earthed).

So please wise me up folks, it isn’t bothering me but I know someone here will be able to clarify what’s occurring here.

[paul_5]

Could be that your second pot is altering the impedance slightly - higher impedance pots always sound brighter than lower ones (500k will deliver more top end than 250k), so maybe it’s that - without seeing a diagram this is just an educated guess though.

[mybass]

5 hours ago, paul_5 said:

Could be that your second pot is altering the impedance slightly - higher impedance pots always sound brighter than lower ones (500k will deliver more top end than 250k), so maybe it’s that - without seeing a diagram this is just an educated guess though.

I'm using 250k pots with the Delano pups...Im guessing along the same lines as you with the pots own impedance playing a part but it surprised me, I expected with no cap. inline that there wouldn't be any sweep variation available.

I've looked online at taking out the tone pot before committing and the general comment is that the pickups will be 'allowed' to output more top and bottom end, so I stuck with the 250k pots.....thanks.

[itu]

2 hours ago, mybass said:

I've looked online at taking out the tone pot before committing and the general comment is that the pickups will be 'allowed' to output more top and bottom end...

Pots can affect high frequencies, but not so much of the middle and the lows. If you remove all pots, the pickup can push out slightly more. If you use two pickups in one "passive" circuitry, they affect each other. You can separate them using battery powered buffers (Noll Mixpot or similar).

[mybass]

3 hours ago, itu said:

Pots can affect high frequencies, but not so much of the middle and the lows. If you remove all pots, the pickup can push out slightly more. If you use two pickups in one "passive" circuitry, they affect each other. You can separate them using battery powered buffers (Noll Mixpot or similar).

Thanks for this…

[Geek99]

11 hours ago, paul_5 said:

Could be that your second pot is altering the impedance slightly - higher impedance pots always sound brighter than lower ones (500k will deliver more top end than 250k), so maybe it’s that - without seeing a diagram this is just an educated guess though.

Yeah I was going to say that same learned and knowledgeable thing also. Honestly, I really was 

[Andyjr1515]

Anything in between the pickup and the jack has the potential to change the sound so yes, an extra pot in the chain will have an impact, as does the volume pot itself.  

 

Ref the tone pot, as far as I understand these things, the capacitor's job is to bleed off the treble frequencies from the signal.  Without the capacitor, the whole signal spectrum is bleeding off through the pot coil and so yes, the tone will be affected, although in a different way than if a capacitor was in the chain.

 

A number of the basses I've done for Tom have had no volume pot or tone pot - the pickup is wired direct to the jack.  It makes an interesting comparison to if you add just a volume pot or a volume and tone pot. 

[mybass]

On 27/07/2021 at 09:50, Andyjr1515 said:

Anything in between the pickup and the jack has the potential to change the sound so yes, an extra pot in the chain will have an impact, as does the volume pot itself.  

 

Ref the tone pot, as far as I understand these things, the capacitor's job is to bleed off the treble frequencies from the signal.  Without the capacitor, the whole signal spectrum is bleeding off through the pot coil and so yes, the tone will be affected, although in a different way than if a capacitor was in the chain.

 

A number of the basses I've done for Tom have had no volume pot or tone pot - the pickup is wired direct to the jack.  It makes an interesting comparison to if you add just a volume pot or a volume and tone pot. 

Thanks for this info….I have opened the cavity, played an open string and then tried both the capacitors (by holding them against the pot and tag) . Not much difference with the top end but of course when I turn the pot to reduce treble it is a different sound and slightly less volume with it…..I’ll keep trying the two options for a while.