Buzz on active input but not passive

[shackleford]

I have an SWR Silverado Special and a Warwick Corvette Standard 5.

When I plug into the active input, I get the buzz. When I plug into the passive/active input, I don't get the buzz.

[B-string]

Sounds like shorting contacts on the passive/active jack are not closing when unused.

[KJung]

Originally Posted by B-string

Sounds like shorting contacts on the passive/active jack are not closing when unused.

+1 This was a BIG issue with the Mesa heads a while back and they literally replaced the 'active' input with an active/passive switch (used a bit baseball bat switch that fit into the same 'hole' as the original second active input... problem solved).

Would some sort of contact cleaner applied to an instrument cable work with a bunch of plugging/unplugging to test that theory out/fix the issue?

[B-string]

It very well could. I would suggest a VERY short spray in the jack as well. DeoxIT or RidOX. No WD-40 unless you want to trash the amp.

[KJung]

Originally Posted by B-string

It very well could. I would suggest a VERY short spray in the jack as well. DeoxIT or RidOX. No WD-40 unless you want to trash the amp.

Worth a try for the OP, especially if he is careful with amount and uses the right stuff.

[shackleford]

Where can I get DeoxIT?

So, I put a short spray into the passive/active input and plug/unplug an instrument cable that has the contact cleaner already sprayed on it?

[KJung]

Originally Posted by shackleford

Where can I get DeoxIT?

So, I put a short spray into the passive/active input and plug/unplug an instrument cable that has the contact cleaner already sprayed on it?

Kind of an 'either or'. VERY short spray so the stuff doesn't drip all over everything, and then work the inputs with a cable to allow the cleaner to get to where it needs to go. Seems like that might be worth a try prior to heading to the chop.

I assume Radio Shack would have this, but hopefully, B-String (who has an electronics/repair background I believe) can point you in the right direction.

[shackleford]

I'll probably head to Radio Shack today. Do I have to get DeoxIT or could I get some other contact cleaner?

[KJung]

Originally Posted by shackleford

I'll probably head to Radio Shack today. Do I have to get DeoxIT or could I get some other contact cleaner?

I would PM B-string just to make sure, or put up a separate thread asking about 'appropriate products' to clean amp input jacks. I know there are other brands that are just fine, but also know there are some products that have solvents or whatever that are NOT OK.

[B-string]

Some Radio Shacks will carry it (if they are a company store). Dealer stores are a crapshoot. A good electronics store (like Fry's Electronics) will carry it. Radio Shack's contact and tuner cleaner is not good for this or just about any use really.
Rid-Ox works well also. Online you can order from www.partsexpress.com .

[KJung]

Originally Posted by B-string

Some Radio Shacks will carry it (if they are a company store). Dealer stores are a crapshoot. A good electronics store (like Fry's Electronics) will carry it. Radio Shack's contact and tuner cleaner is not good for this or just about any use really.
Rid-Ox works well also. Online you can order from www.partsexpress.com .

It was that Radio Shack product that made me nervous (I remember hearing some bad stuff about that in the past) giving any exact recommendations, since I know you can screw up a bit if you use the wrong product. Cool.

[B-string]

Yes I had a customer use the RS "cleaner" on a Marshall 6100's pots. Took 3 hours to clean up the mess and four pots were conductive plastic that were destroyed.

[DiabolusInMusic]

I get Deoxit from my L&M (Canadian GC) I imagine it is cheaper at an electronics store though.