SF Twin Reverb, Reverb issue

Discussion in 'Amp Tech Center' started by gnd567, Feb 25, 2020.

  1. gnd567

    gnd567 Tele-Meister

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    My reverb cables on my SF Twin Reverb were giving me trouble. I would have to jiggle them to get the reverb to work. The jacks appear fine, the cables were in pretty rough shape though. I ordered some new reverb cables and installed them today and now the reverb doesn't work at all! I hooked them up correctly and double checked everything. The reverb was working yesterday. I can't put the old cables back on because they fell apart when I disconnected them.
     
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Try swapping them around just in case they aren't right? Just swap the connectors on the back of the amp side.

    Next thing, maybe moving the tank around killed it. The wires on the baby transformers inside the tank are super tiny and fragile. If you've got another amp with a similar reverb tank (deluxe reverb, princeton, some non-solid state reverb circuit) hook up that tank and see what happens.
     
  3. schmee

    schmee Poster Extraordinaire Silver Supporter

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    Try tightening the outside "grippers" of the cord end RCA jacks? Also, clean the outside of the amp mounted RCA jacks with steel wool, or super fine paper..
    Did you put real reverb cables in or those plastic ones? The plastic ones often have really bendy grippers.
    and as corliss says, the tanks are super easy to kill....
     
  4. gnd567

    gnd567 Tele-Meister

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    I tried swapping the cables, didn't work. The grippers seem to be fine too and the jacks look fine to me. I guess it's the tank? It worked fine yesterday other than the cables. The new cables are made just like the old ones in the 60s-70s so they should be fine.
     
  5. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Ooooooh so you sprang for the fancy braided ones? Those are nice.

    Yeah, there's really not much left if it was working before. Tank. It's possible the tube decided that exact moment was the time to die, but tank seems more likely.
     
  6. gnd567

    gnd567 Tele-Meister

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    I changed the tube too. Nothing. Must be the tank?
     
  7. Dacious

    Dacious Poster Extraordinaire

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    When you move the cab with the amp on, does the reverb go crash?
     
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  8. BobbyZ

    BobbyZ Doctor of Teleocity

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    If nothing else mentioned already gets it. Try your old cables again, maybe the new ones are bad? Pretty easy to get one loose wire and short out a cable while soldering the ends on, or a bit too much solder.
    You could check um with an ohms meter too.
     
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  9. gnd567

    gnd567 Tele-Meister

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    I can't try the old cables, they fell apart in my hands unfortunately. I also tried moving the amp to see if i could hear the reverb "crash" but I didn't hear it. I thought I was pretty careful with the reverb tank but I'm beginning to think that it has gone bad. It worked fine until today when I changed out the cables. I tried swapping tubes too and again, nothing.
     
  10. BobbyZ

    BobbyZ Doctor of Teleocity

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    Got an ohms meter? Only take a minute to find out if the new cables are shorted out or not with one.
    Could be something in the tank got knocked around too but I like to verify.
     
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  11. moosie

    moosie Doctor of Teleocity Ad Free Member

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    Tanks are so fragile. It's become the FIRST thing I check when reverb fails. Easy enough to test, with a bunch of amps on the wall. There's usually an amp close enough to sneak it's cables over to the problem amp.

    And yes, those vintage style braided cables are sweet. That's all I get anymore.
     
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  12. BobbyZ

    BobbyZ Doctor of Teleocity

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    I've actually been really lucky with reverb tanks. The two most gig beat amps I've got are a SFTR and a '62 Reverberocket. Those amps look like they were tossed in a van by drunks many times over the years. Far as I know the tanks in both are OEM.
    But they can go bad so I keep a pan handy on the bench. Ok my "bench" is in boxes right now but you get the point.
    The "bad tanks" I've had all turned out to be caused by other issues. Tubes, connections, cables, old cathode bypass caps in the circuit.
    Like I said, I've been lucky. :)
     
  13. gnd567

    gnd567 Tele-Meister

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    I took it to my tech today. The tank is dead. I can't believe it. It worked all this time and then when I decide to change out the wires, it dies. Oh well. New tank is on the way.
     
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  14. corliss1

    corliss1 Friend of Leo's Platinum Supporter

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    Well now you know for sure :D
     
  15. moosie

    moosie Doctor of Teleocity Ad Free Member

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    So, you got a new tank, and new cables!


    Time for the tube to go... :lol:
     
  16. gnd567

    gnd567 Tele-Meister

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    No kidding! haha
    Luckily, I have plenty of tubes.
     
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