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Thread: Lost reverb on my '80 Twin

  1. #1
    Forum Member
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    Lost reverb on my '80 Twin

    hey dudes,

    switched the pre-amp tube...rvrb. still not functioning.

    i unplugged both tank wire from amp and checked for an open.

    i think i did it correctly.....one lead on the inside "pin" and one on the

    outside "ring"--?? my leads are polarized...does one need to go to

    a certain part, etc.??


    my readings for one cable was around 1 ohm. the other was

    around 200 ohms. from what i could find on the net....the 200

    ohm reading is probably cool. 1 ohm is a bit low? should be around

    8 ohms or so??

    any comments, thoughts or goofs are welcome!!

  2. #2
    Forum Member
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    Re: Lost reverb on my '80 Twin

    The reverb circuit is a little amp in and of itself. The RCA jack marked output on the rear of your amp is driven off of the small output transfomer mounted inbetween your preamp tubes. If you get another cheap RCA cable and plug it into the output jack and then strip the other end and hook that to a speaker you will have a 1.5 watt amp, and this is one way to check that the drive end of the reverb circuit to the pan is ok.
    You could also hook up a volt meter set for A/C instead of teh speaker too look for drive output instead of listening for it.
    The to test other RCA jack (recovery end of the circuit) on the rear of the amp is to plug in a RCA cable or even just a bare RCA plug and touch it tip connection with the reverb control turned up, you will hear a buzz just like tapping the end of your guitar cable when it is unpluged from your guitar with the channel volume up.
    If both of these test prove out both ends of the reverb circuit, than you have one end of the pan that is dead if both feed cables check out good.
    If you tap hard on the pan with the reverb turned up and hear the tapping, then the recovery end of the pan, cable and circuit is ok.
    Most pans fail due to the small feed wires coming off at the pans female RCA jacks( which can be fixed) or at the small transformer/solenoid, which can not be fixed.
    Also the spring mounting wires have been known to snap off at their end where they are soldered to there tower caps.
    This can be reapaired also, as I have done it once, but it takes so dam long is best to just get a new pan as they are all of 26 bucks!

  3. #3
    Forum Member Offshore Angler's Avatar
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    Re: Lost reverb on my '80 Twin

    Did you check both reverb tubes?
    "No harmonic knowledge, no sense of time, a ghastly tone, unskilled vibrato, and so on. Chuck is one of the worst guitar players I know" -Gravity Jim

  4. #4
    Forum Member Kap'n's Avatar
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    Re: Lost reverb on my '80 Twin

    Does it make a sound if you shake the tank?
    Several guitars in different colors
    Things to make them fuzzy
    Things to make them louder
    orange picks

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