1. Welcome to TalkBass 2014! If you're new here, we just went through a major site upgrade. Please post all concerns and bugs to the Forum Usage Issues forum. We will be monitoring that forum. Thank you for all of your feedback.

    The TB Android app is working, you may need to uninstall/reinstall. The iPhone app is still pending approval by Apple. If you haven't yet, try using your mobile browser - TalkBass is responsive to any screen size.

    Please read the TalkBass 2014 FAQ for lots of great info on the new software.

My Project - And I need help...

Discussion in 'Amps [BG]' started by Hobobob74, Jan 17, 2013.

  1. Hobobob74

    Hobobob74

    Joined:
    May 21, 2007
    Likes Received:
    0
    So, probably 5 years ago, I got this little gem of a PA Tube Amp. Its just been sitting in my basement ever since, but I finally might have found something to do with it.

    It only has an old school mic. jack, but i have a converter to switch that to a 1/4" female jack to plug a bass or guitar or whatever into.

    So, I'm thinking I'm gonna build a little wood cab to put it in and make a little head out of it.

    Here is my questions:

    1. The speaker connections are just for the wires. But there is a 8 ohm and 4 ohm screw. So how would I wire up a jack for say, 8 ohm? Ill attach a picture for a better idea, lol.

    2. Can I just disconnect the volume and bass/treble pots, add wire, and put the knobs on the outside of my new 'head cab'.

    Hopefully this turns out cool, lol:bassist:

    Attached Files:

  2. Hobobob74

    Hobobob74

    Joined:
    May 21, 2007
    Likes Received:
    0
    some more

    Attached Files:

  3. Hobobob74

    Hobobob74

    Joined:
    May 21, 2007
    Likes Received:
    0
    underbelly

    Attached Files:

  4. Nate74

    Nate74 Supporting Member

    Joined:
    Mar 3, 2007
    Likes Received:
    0
    1. The speaker connections are just for the wires. But there is a 8 ohm and 4 ohm screw. So how would I wire up a jack for say, 8 ohm? Ill attach a picture for a better idea, lol.

    Drill a hole, put the female 1/4" jack into it, wire the appropriate wires to it, preferably with solder not masking tape.

    2. Can I just disconnect the volume and bass/treble pots, add wire, and put the knobs on the outside of my new 'head cab'.

    Yes.
  5. dhsierra1

    dhsierra1

    Joined:
    Dec 12, 2009
    Likes Received:
    0
    yup. You'll want your ground wire connected to the "C" screw terminal and the hot (positive) to the 8 ohm screw.

    Looking at that schematic seems like you'll have around maybe 8 or so watts. Go with a high efficiency speaker if you're going to put bass through it.

    Looks like a fun project, good luck and keep us posted :cool:
  6. BassmanPaul

    BassmanPaul Gold Supporting Member

    Joined:
    Aug 25, 2007
    Likes Received:
    3
    Honestly I think you'll find that that amp will not give you a lot of low end. It'll make a better guitar amp.
  7. Steve Dallman

    Steve Dallman Supporting Member

    Joined:
    Mar 5, 2006
    Likes Received:
    0
    It's not far from the design of a Champ. It could be wired to be a little more bass friendly, but you've got low plate voltage, limited B+ filtering, and about 5 watts. It could be made into a better guitar amp, but it would still be just a few watts. It has a pretty small output transformer to boot. You could put in a SS rectifier to get the voltage up some, and that would allow you to increase the B+ cap, which would aid a little in headroom.
  8. Hobobob74

    Hobobob74

    Joined:
    May 21, 2007
    Likes Received:
    0
    Yeah, I would probably just use it for a practice guitar amp.

    But I've heard that it would make a good harp amp too
  9. B-string

    B-string Supporting Member

    Joined:
    Nov 21, 2008
    Likes Received:
    10
    Nice little cathode bias Class A amp. Use shielded wire to extend the wire on the pots, old balanced mike cable will do.

Share This Page