1. The Gear Page is run by musicians for musicians. We listen, we learn and if we misstep we are not afraid to do the right thing. We proposed some changes to the Emporiums. Based on feedback from members, we have decided to not go ahead with those changes. However, it has also highlighted that we need some community input into what is working and what is not working for members here. Primarily focused on the Emporiums, we'd like input on your thoughts about TGP and how things work in the Emporiums for you and how you'd improve them. The discussion thread on the is here!

    Dismiss Notice

High pitch sound coming from amp..ugh!

Discussion in 'Amps and Cabs' started by GregWV, Feb 25, 2012.

  1. GregWV

    GregWV Member

    Messages:
    293
    Joined:
    Jun 21, 2010
    I've got a new VoxAC15HW1 and when I play certain chords I get a high pitched note that sounds like a spring rattling.

    Microphonic tube?

    Or, is it just the speaker making the tubes rattle?
     
  2. rgee27

    rgee27 Supporting Member

    Messages:
    380
    Joined:
    Jul 19, 2003
    Location:
    Santanaland
    Microphonic tube for sure... tap each tube with a pencil to see which one is making the noise.
     
  3. GregWV

    GregWV Member

    Messages:
    293
    Joined:
    Jun 21, 2010
    Tap with pencil While it is on? What will it sound like?

    Power tube or pre amp tube?

    Could it be rectifier?

    Thanks- I have gig in morning.
     
  4. lang.murphy

    lang.murphy Member

    Messages:
    3,557
    Joined:
    Dec 9, 2009
    Location:
    Lawrenceville, GA
    Well... I can't say for sure what the root cause is for that high pitched note that sounds like a spring rattling. Yeah, might be a microphonic tube...

    So... anyway... usually the first step in TS'ing a tube amp is to swap in different "known good" tubes. Lacking a spare tube inventory, I guess the next best thing would be to swap tubes from one location to another. A microphonic tube in V1 might not have the same effect in Vx... x being anything other than 1. ;-)
     
  5. tnt365

    tnt365 Supporting Member

    Messages:
    2,984
    Joined:
    Apr 26, 2010
    Location:
    Oregon
    yes tap the tubes while it is on and the guitar volume is up. If it rings or makes a noise then it may be microphonic. Tubes are kinda cheap, so go buy a few preamp tubes before your gig (most likely the problem, cross your fingers) and replace the ones you have. If it fixes the problem (which over %50 over the time it will) then you are lucky. If not, you want a tech to look at it if you are inept. That is a nice amp, so putting a little love into it is gonna be worth it. Cheers!
     

Share This Page