Buzz on active input but not passive

Discussion in 'Amps [BG]' started by shackleford, Jan 5, 2013.


  1. shackleford

    shackleford

    Joined:
    Jan 2, 2006
    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.
  2. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    Sounds like shorting contacts on the passive/active jack are not closing when unused.
  3. KJung

    KJung

    Joined:
    Apr 9, 2005
    Location:
    Wisconsin and Upper Michigan
    +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?
  4. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    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.
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  6. KJung

    KJung

    Joined:
    Apr 9, 2005
    Location:
    Wisconsin and Upper Michigan
    Worth a try for the OP, especially if he is careful with amount and uses the right stuff.
  7. shackleford

    shackleford

    Joined:
    Jan 2, 2006
    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?
  8. KJung

    KJung

    Joined:
    Apr 9, 2005
    Location:
    Wisconsin and Upper Michigan
    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.
  9. shackleford

    shackleford

    Joined:
    Jan 2, 2006
    I'll probably head to Radio Shack today. Do I have to get DeoxIT or could I get some other contact cleaner?
  10. KJung

    KJung

    Joined:
    Apr 9, 2005
    Location:
    Wisconsin and Upper Michigan
    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.
  11. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    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 .
  12. KJung

    KJung

    Joined:
    Apr 9, 2005
    Location:
    Wisconsin and Upper Michigan
    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.
  13. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Location:
    Lake Havasu City, Az USA
    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.
  14. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism Gold Supporting Member

    Joined:
    Dec 22, 2010
    Location:
    Saskatoon, Saskatchewan
    I get Deoxit from my L&M (Canadian GC) I imagine it is cheaper at an electronics store though.

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