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SVT Cabinet Wiring

Discussion in 'Amps and Cabs [BG]' started by MsLadyEvans, Aug 3, 2004.


  1. MsLadyEvans

    MsLadyEvans

    Apr 20, 2004
    Hello all, I'm looking for resources to help with wiring a 70s era SVT cab. I recently purchased one and I'm going through it all replacing everything from the input jack to the tolex to the feet cups to a couple of blown speakers. I know the parallel wiring scheme is of utmost importance, and so is the cabinet's seal at every speaker, but since I've not done any of this before and I'd like to get it right the first time, anything online that any of you might know of to help out would be great. Its always helpful to have a guide of sorts. Thank you very much.
     
  2. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    The best advice is to draw sketches of anything that you don't think you will remember when it comes time to put it together again. And number wires.

    You already know that all the speakers go in parallel. The issue is getting the wires back in the way they came out, so thay all reach where they need to go.

    For convenience, I suggest getting some masking tape and a marker pen. Label the wire ends with numbers, and make a sketch of the speaker locations and the corresponding numbers. Do it as you remove speakers, so you won't get confused later.

    Make a sketch of the wiring to each speaker, also. The wires must go back on so that all the speakers have the same polarity.
    That means that one wire connects to the equivalent terminals on each speaker. The white wire, for instance might connect to all the "left-hand" speaker terminals.
    That ensures the speakers all work together, moving the same direction.
     
  3. MsLadyEvans

    MsLadyEvans

    Apr 20, 2004
    Jarrold,

    Yeah that's probably the best way to go. I, for what are certainly unfounded reasons, just have a suspicion that someting might be a miss from the get go. The jack was poorly replaced and a speaker or two are aftermarket, and even though everything looks fine, and the cab functions properly, instead of using someone elses noodling for a template I figured I'd try to find an exact diagram to check everything out. Peace of mind and all that. Definitely thank you for the advice though.

    Another quick question - you work for ampeg, so maybe you'll know if there is any validity to this. Someone who works for SLM and is apparently either one of the 'old' ampeg guys, or at least knows quite a bit about the ampegs of yore, told me over the phone that the cabs were in production a bit before the heads came out in '69. I thought head and cab were coeval prior to this, and now I don't know. He even said they were being made as early as '65-'66 while they weren't sold to the public until '69. Everyone I've ever asked about this has either thought I was nuts or talked to someone at ampeg who was nuts. Ever heard anything remotely like this? Thanks again

    Matt
     
  4. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    If the wiring is in doubt, then just follow the rule that one pin of the jack must go to all the "left hand" speaker terminals, and the other must go to all the "right hand" terminals.

    Exactly how they get there is not as important. Because of the construction of the 8-10, you are more-or-less forced to wire from one to the next, and all you need to do is be consistent on polarity.

    As far as the cabinets, nobody here was with Ampeg then, so exact knowlege isn't readily available from "eyewitnesses". I am no spring chicken, but I wasn't in the biz then, nor with Ampeg.

    The SVT and cab was available to a couple bands before it actually went into production, maybe that is what the people meant? Could have been seen on stage.