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TC RH750 question

Discussion in 'Amps and Cabs [BG]' started by steelbed45, Mar 31, 2014.

  1. steelbed45

    steelbed45 TRemington Supporting Member

    Feb 23, 2011
    Nolanville, TX
    My brand new, fresh out-of-the box rh750 is set up and there's an issue.

    The amp makes a loud, high pitched noise at a constant frequency and gets louder/softer with the volume inputs. It only makes this noise when something is plugged into the input jack.

    I tried the following with all tone settings on flat/comp off/tube off/tweetertone fully rolled off.

    Different power cord - loud noise
    Changed the Speakon cable - loud noise
    Tried a different bass with the same cable - loud noise
    (The first bass was active, the second passive, same result)
    Changed the cable 11x (basically went through all my cords) - loud noise
    No bass, just plugging in cords - loud noise
    Turning the amp on with no cord in the input jack - no noise
    Switching bass heads - no noise

    I tried looking on the internet/tc support site/TB threads and I'm not finding a solution so far.

    Has anyone experienced this with this head? It would be great if I simply missed a button or switch...
  2. drpepper

    drpepper Supporting Member

    Jul 20, 2009
    Columbia, Maryland
    No magic button or switch that I'm aware of, sorry.

    Sounds like it probably needs to go back.

    Do you get the same thing through headphones? I assume so...it sounds like the problem is at the input.
  3. steelbed45

    steelbed45 TRemington Supporting Member

    Feb 23, 2011
    Nolanville, TX
    I missed that one. I tried the headphones and had the same result. Loud noise with the cable, no noise when I unplug it.

    Thanks for the reply, back it goes.
  4. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Why did you even have to ask??? You paid hard earned money for the thing. If it ain't perfect send it back and get one that is!!
  5. Many production amps short the input when no cable is inserted, that is most likely why it is quiet with no input cable. Amp needs to go back for repair/replacement.