Volume drop when turning the tone pot?

[add4]

Hello to everyone,
I am new to the changing pickups thing, and i just recieved my first  pickup yesterday, a beautiful bare knuckle manhattan P90.
So far, i just installed the pickup and didn't touched to the tone pot and everything works fine, but i experience a volume bleed then i turn down the tone (this problem was there before the pickup change, but i thought i could be able to sort it out when changing the pickup if is was something obvious like a bad soldering joint or something like that, but it turns out i could not sort it out).
I thought that it could be caused by
- the cap value.
- the wiring scheme.. i noticed that the wiring of my guitar doesn't follow tim's scheme: the tone cap is between the right lug of the tone pot, and grounded directly, instead of being between the volume and tone pot.
- bad sodler joint. but i think that's not it since the tone control works, i just have to turn the volume up when the tone is on 0 to keep the same volume.
I have read that a bad cap value could cause that on the warmoth forum, but i was not able to identify my cap value with what's written onto it, i thought maybe someone could help so i took a pic. The pic shows you the stock  cap that i have currently in my guitar.

Any help or idea to fix that volume drop is appreciated
Best
Arnaud

p.s. As far as the pickup goes, i soldered it this morning before going to work and only played 10 mins before leaving, but it seems extremely balanced and sounds great. In fact, with my old pups (gibson classic 57) i had a parametric EQ always on to add highs and medium highs, and i have the same kind of sound now, without the EQ, only with better dynamics and subtelty. and i have not played with the pickup height yet..

 

[add4]

Ok i found the problem
When i took my guitar this evening, it started to hum and scratch so mucjh that i put all the electronics out and re did everything. Turns out the tone pot was not grounded anymore, the solder joint had broken. I resoldered it and the tone pot acts normally.
I still don't know what that cap value is though.
Best

 

[-CB-]

If you access the tone pot by way of the output of the volume control, you'll experience volume drop that can be excessive.  If you use the raw signal - the input to the volume control - as the signal source for the tone pot, then the volume drop will be much less (still a little).

The first scenario is especially noticed when the volume control is rolled off even just a little bit.  The series resistance combined with the treble bleed off... and volume hugely suffers.

So... whatever lug the pickup wire is connected to (or wire from the switch, whatever... full pickup signal strength) make that the same lug that that feeds over to the tone control.

 

[Steve_Karl]

If you access the tone pot by way of the output of the volume control, you'll experience volume drop that can be excessive.   If you use the raw signal - the input to the volume control - as the signal source for the tone pot, then the volume drop will be much less (still a little).

The first scenario is especially noticed when the volume control is rolled off even just a little bit.  The series resistance combined with the treble bleed off... and volume hugely suffers.

So... whatever lug the pickup wire is connected to (or wire from the switch, whatever... full pickup signal strength) make that the same lug that that feeds over to the tone control.

Thanks!
I snagged this for my wiring notes for when I do my 2 humbucker super strat.