Varitone switch help

[themaestro78]

Howdy all! I just finished wiring up a 6 position varitone switch leaving the first position with no capacitor and the last 5 with different value caps. On the first position I Am getting a lot of buzzing. I followed a schematic that said hook nothing up to the first peg. Is this normal or did I miss something. The second position also buzzes slightly with a .01 cap but with a little volume adjustment is tolerable. Any comments or suggestions would be helpful

[themaestro78]

Also when in the fist position the buzzing subsides drastically when I touch the strings but doesn't go away altogether. I do have the switch grounded by the housing

[line6man]

What kind of buzzing?

It sounds like all of the higher value capacitors are bleeding off the noise to ground, while the low value and bypass positions allow you to hear what the bass really sounds like. In which case, it is not a switch wiring issue.

How's your grounding and shielding?

[themaestro78]

I have all the cavities shielded with aluminum tape that I use for hvac vents ( I had it laying around the house) and everything seemst to be grounded pretty well since those are the only two positions that humm. On the other positions I don't even get a humm if I have the pickups at different volumes. It is a squire affinity jazz by the way

[line6man]

Originally Posted by themaestro78

I have all the cavities shielded with aluminum tape that I use for hvac vents ( I had it laying around the house) and everything seemst to be grounded pretty well since those are the only two positions that humm. On the other positions I don't even get a humm if I have the pickups at different volumes. It is a squire affinity jazz by the way

To my knowledge, the adhesive on HVAC tape is not electrically conductive, and aluminum is difficult to solder to, which makes it difficult to properly shield a bass, since every piece must interconnect with a low impedance path to ground. Have you checked all the shielding with an Ohm meter, to ensure a 0 Ohm continuity throughout all ground points?

[themaestro78]

Hmm I didn't know you grounded to the sheilding. I thought it just kind of reflected the interference away

[line6man]

Originally Posted by themaestro78

Hmm I didn't know you grounded to the sheilding. I thought it just kind of reflected the interference away

There's your problem.

Read up on Faraday Cages.
Faraday cage - Wikipedia, the free encyclopedia

[themaestro78]

Yes sir! I grounded to the sheilding and its a definate improvement. And you were right the adhesive side of the tape has no continuity with the multimeter but the top side does something is better than nothing for now