Awful background noise on 66 Princeton Reverb

Discussion in 'Amps and Cabs' started by GibsonSGgirl, Feb 24, 2012.

  1. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    Hey all,

    I'm trying to diagnose what is wrong with my 66 Princeton Reverb. I was playing through it last night (volume was on 1) and it started making my lower bass notes on my guitar sound staticky. I thought it was the batteries in my Line 6 DL4 that had bit the dust, so I plugged the guitar straight to the amp. Still sounded bad, like there was some noise that seemed to interfere or appear on top of the guitar chords, making it sound muddy and not clear.

    So I thought one of the tubes had gone.

    Well today I decided to investigate it further by making a video of the above background noise and reverb noises. Hopefully someone can figure out what it is, so I know what I need to do to fix it.

    Pay special attention around the 1:13 mark, as that's when the background hiss starts. It sounds like the amp is farting. It's very annoying as I was always lead to believe that Princetons were very quiet amps which was why they were good for recording through.

    Here's the vid, hope it's helpful!

    http://youtu.be/c9_Ao0HbFbA
     
  2. michael stuart 57

    michael stuart 57 Member

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    try the power cord

    reseat the tubes

    vid aint worth much
     
  3. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    It's a new power cord. That shouldn't be the cause.

    Thanks for your kind and helpful suggestions.

    :sarcasm
     
  4. Peeb

    Peeb Member

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  5. Darkness

    Darkness Member

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    When, if ever, was the amp recapped?
     
  6. jb4674

    jb4674 Member

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    I couldn't hear anything when I watched the video on my iPhone. Have you tried different cables? What/where is the amp plugged into? If you have some deoxit, try pulling the tubes out and spray the pins with deoxit and sit them back in the sockets. I'll try to watch the video on a PC to see if there's a difference in the audio.
     
  7. michael stuart 57

    michael stuart 57 Member

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    guitar cord then? short between the headset?

    alert this
     
  8. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    I'm not sure that it ever was. I have been planning to get the caps replaced, just needed to take it in.
     
  9. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    I do notice when I wiggled the tubes in their sockets, that a few of the preamp tubes produced a static sound when moved around or touched.
     
  10. Red House

    Red House Silver Supporting Member

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    Sounds like a noisy pre-amp tube.

    Looking at the back of the amp, the pre-amp tube on the farthest right, replace it, and check for noise. Keep working to the left to see if the noise goes away.
     
  11. fusionbear

    fusionbear exquirentibus veritatem Gold Supporting Member

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    Caps! The electrolytics in the preamp, especially. This is very common with 60's amps...
     
  12. Darkness

    Darkness Member

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    My thoughts exactly.
     
  13. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    Thanks very much! I swapped the v1 preamp tube (the one on the farthest right) with an old RCA one from my 68 Deluxe Reverb, and that cleared all the background noise right up!

    However, the reverb is still noisy, and I'm not sure if it's the tank or the tubes...
     
  14. Red House

    Red House Silver Supporting Member

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    <Elvis_voice> Thanks you, uhhh, thankyouverymuch! </Elvis_voice> :D

    Cranking up the reverb to 10 as you did in the video will make all Fenders sound like that.

    I've always run mine around 3. Start/experiment there, you won't need much more or less than that.

    If it's still noisy at 3-ish, then change-out the 3rd tube from the right and/or the 4th tube.
    :beer
     
  15. GibsonSGgirl

    GibsonSGgirl Silver Supporting Member

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    Yeah I was just trying to show what it sounded like. I normally run it around 3 or 5. However, it's noisy when it's on, that's for sure! I'll try to swap out the 2 tubes you mentioned. Dumb question tho, which ones should I pull from my Deluxe Reverb that would match up with the reverb ones on my PR? Thanks!!
     
  16. Red House

    Red House Silver Supporting Member

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    Firstly, I need to make a correction, the reverb tubes on a Princeton Reverb are:

    v2 = 12at7 - the reverb driver
    v3 = 12ax7 - the reverb recovery

    With that said, your Deluxe Reverb:

    v3 = 12at7 - the reverb driver
    v4 = 12ax7 - the reverb recovery
     

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