1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Using a vintage tube PA head

Discussion in 'Amps and Cabs [BG]' started by dmaki, May 31, 2004.

  1. dmaki


    Apr 29, 2000
    I friend of mine gave me a couple of 1960's PA heads a few years ago and I just stumbled upon them in my basement this weekend. I am wondering A) what I should do to make sure they're safe to use and B) what I have to do to hook them up.

    They are both Bogen brand amps, Challenger series, one being a CHA 10 and the other a CHB 35. They are all tube. There is no watt rating on the CHA 10 (I assume its 10W), but the CHB 35 is rated for 35W (150W with auxilary power -- how does that work?). I may end up using one or both for guitar as they'd probably be pretty quiet on bass.

    I've never had any experience with vintage equipment. There is no 1/4" input jack (just screw-on mic inputs and RCAs), no 1/4" output jack (just a series of small "holes" in a circle with different ohm ratings next to them), and one has a bunch of wires coming out of the back that looks like it may have been attached to an old Jensen pre-amp I found beside the amps (which also just had a bunch of wires hanging out of it). I'm pretty sure I should have it looked at...

    I know you can get adapters for the input (so I can use a 1/4" jack), but I don't know about the output. Does it use just regular speaker wire? How would I get it to drive a cab?

    If you can give me any advice I'd really appreciate it.
  2. 150 watts is the AC current maximum DRAW rating of the unit with it's auxilary outlet, not its audio output.

    RCA to 1/4" converter cables should do fine, but you'll probably need a preamp in front of them. You'd be better off to pull the mic inputs and rewire them with 1/4" jacks if you want to just use the amp.

    Sounds like it uses a jumpered output imedance selector, and the jumper plug is missing. You'll have to re-wire the output of the transformer to jacks if you want to use it.

    Without a better discription, I have no idea what you are referring to. You REALLY need to get in touch with someone who has some experince with this type stuff who can show how and why you do things the way it will require. I've got a Bogen Challenger 100, and it's pretty useless for anything because it was meant to be an industrial intercom amp with minimal fidelity and one of the shoddiest output transformers I've ever seen. You MIGHT get a wooly lo-fi, extremely low volume guitar tone at BEST.