Capacitor or Potentiometer Broken?

[thegummy]

I had to re-wire my J-style bass after a bit of a drill accident and decided I'd take out the series/parallel switch since I don't use it.

So I replaced the push-pull pot with a brand new normal (mini) pot and moved across the capacitor that was already on there. When I removed it from the push-pull pot I used a heatsink but, in my haste, I didn't use one when soldering it on to the new pot.

When wiring it back up the tone control didn't seem to do much audibly. I hooked it up to the computer and looked at a frequency analyzer and it does make a difference visually but it doesn't go from bright to thumpy like it did before.

How can I test to see if it's the capacitor that's now broken or if it's the new pot that's the problem?

[ikay]

If you have a multimeter you can check the pot by measuring resistance between the centre lug and the end that isn't grounded (sweep the pot and the resistance should go from zero to the full pot value). Are you sure it's wired correctly? Post a pic if you can.

[thegummy]

I don't have a multimeter unfortunately.

As far as being wired correctly; I'm fairly sure the wires are connected to the places they're supposed to be but the soldering job itself may not be perfect, I could possibly try re-wiring it again when I have a day off.

Here's a photo of it, although the wiring is pretty messy so not sure how useful the pic will be.



Any idea what would happen if a potentiometer was hooked into the circuit like a tone control is but with the lug connected directly to ground rather than via a capacitor? Would it act as another volume control? Just wondering if I could perhaps temporarily bypass the capacitor to test if the pot itself works?

[Norris]

That does look pretty messy and the soldering isn't the cleanest I've ever seen. I assume that the green wire is the signal from the volume pot? The solder on the tag that the cap is on looks mighty close to the centre tag of the tone pot - are you sure you haven't got a short there?

[thegummy]

Thanks for the reply norris. I'll disconnect the tone pot and re solder it to see if that fixes it.

Before hand I had this grand idea of a perfectly wired, neat and tidy wiring but actually doing the frustrating job of soldering in such a cramped space I was happy with anything that worked lol

[gary mac]

That does look messy, even if you cure the existing problem, to me it looks as though it has the potential to let you down.

If you are not handy with a soldering iron, my suggestion would be to contact BC'er Kiogon and get him to supply you with one of his solderless looms. It will look lovely and of course, work perfectly.

[KiOgon]

^ Cheerz Gary ^

That does look a mess! Here's one of mine - https://www.dropbox.com/s/jvagc86u3e2qdt2/2017-08-23%2015.58.36.jpg?dl=0 just add pick up wires and bridge earth.

It's not often caps get damaged by soldering heat, it's more likely a pot would suffer if too much heat was applied but that doesn't look likely from your picture. If you took out the series/parallel switch what is the other push/pull switch in the photo?

John

[thegummy]

That does look very neat.

The remaining push pull switch is a coil tap.

From what you say it seems like there's a good chance the issue is with a connection. I found it kind of weird that the tone control works to a measurable degree but not as audible as it should be.

I'll re connect it up today and report back.

P.s. Nice avatar pic, it's currently the pic on my calendar for August which reminds me it's time to turn over to September

[thegummy]

Before I was about to open it up I had another quick play at it and I'm wondering if maybe the tone actually is working as it should and I'm just so used to my P-Bass that I'm forgetting what the J sounds like with the tone rolled off.

Here is a recording - does it sound like a J should with the tone off or is there a problem here?

https://www.youtube.com/watch?v=e48_Nv4u-w0

[ikay]

Sounds as it should do to me. Your P may have a .100 cap which sounds darker when rolled off than the standard .047 cap in a J.

[NickA]

If you want more roll off, just put a bigger value Capacitor in ... or another one in parallel. Each time you double the capacitor value you will halve the roll off frequency (ie bring it down an octave).

Better still ... go active and put a double or more pole filter in ;¬)

[thegummy]

[quote name='ikay' timestamp='1504338793' post='3364158']
Sounds as it should do to me. Your P may have a .100 cap which sounds darker when rolled off than the standard .047 cap in a J.
[/quote]

I looked up the specs of the P and you're right. It must be because I'm so used to that that I thought the J tone wasn't working. Think I'll put a 0.1 in there.

Thanks for the info and sorry if I've wasted anyone's time with the initial post.