Princeton reverb ri spring buzz?

Discussion in 'Amp Tech Center' started by fleacr, Mar 31, 2013.

  1. fleacr

    fleacr TDPRI Member

    Posts:
    7
    Joined:
    Mar 8, 2012
    I know the cab buzz of this amp is well covered on here but this is different. While playing a D on the 7th fret most noticeably there is a spring nose that engulfs the whole speaker. I've switched to a 12" Weber blue dog...I've experimented taking out all the tubes, putting them in different places,etc...I've shored up the chassis with felt,I have tube dampers on the preamp tubes...I've changed the power tubes and back..I've tightened all screws in the chassis..No matter what I get the spring sound which is most pronounced on the d...my thinking is maybe the gz34 is microphonic but it was switched out too..any ideas?
     
  2. fleacr

    fleacr TDPRI Member

    Posts:
    7
    Joined:
    Mar 8, 2012
    Ps..I have jj power tubes, jj ec803s in v1 and nos down the rest of the preamp tubes..jj gz34 as well
     
  3. telex76

    telex76 Doctor of Teleocity Silver Supporter

    Age:
    68
    Posts:
    16,107
    Joined:
    Jun 24, 2006
    Location:
    Fort Worth,Tx.
    Put more dampening material on or around reverb tank.
     
  4. fleacr

    fleacr TDPRI Member

    Posts:
    7
    Joined:
    Mar 8, 2012
    That was a good idea but I completely removed the reverb tank and its still there. Is it possible the gz34 is microphonic to such a degree? To me, it is the only thing left..however I guess the power tubes, despite changing them and having the same issue, could also be suspect bc of their proximity to the speaker. To me it shouldn't be this hard to find, aren't there a limited number of things that can produce an audible rattle? Bastard issue is frustrating :) thanks though!
     
  5. Wally

    Wally Telefied Ad Free Member

    Posts:
    31,760
    Joined:
    Mar 17, 2003
    Location:
    Lubbock, TX
    Have you done the 'tap' test on the tubes and/or the chassis? You might be surprised at what can cause some odd noises through the speaker. I recently had to 'cushion' with foam rubber in between the tagboard and the insulating board underneaeth it in a handwired PRinceton REv II to eliminate a noise like you are describing.
    Tap test on the tubes...if that doesn't lead you to a tube problem, then chopstick tapping o the chassis, the board, and the components can reveal the problem. Caution: this is tech work...inside the chassis..live voltages.
     
  6. fleacr

    fleacr TDPRI Member

    Posts:
    7
    Joined:
    Mar 8, 2012
    Had to take it to my amp tech finally. Bad electrolytic cap I'm told
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.


  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.