So I took apart my B-100R today......

Discussion in 'Amps and Cabs [BG]' started by FuturePrimitive, Feb 5, 2003.

  1. FuturePrimitive

    FuturePrimitive Supporting Member

    Nov 14, 2000
    Rochester, NY
    I'm trying to learn about amps (head/cab vs. pre/power/cab vs. combo). I've decided to take the plunge and go with a pre/power/cab setup. I was looking at my Ampeg B-100R today and noticed that the controls and inputs are actually mounted in a serperate "box" which is mounted to the back of the cabinent. To my untrained eye it kinda looked like it may be a 19" rack-mountable module. I unscrewed the back cover and then removed the "box" from the cabinet. It's actually 17.5" wide but it does indeed look like it could be used in a rack. Couple questions:

    1. Seeing as the B-100R is only a 100w amp is it even worth using as a temporary driver for a 410 cabinet? (I'm eyeballing the Avatar 410) Will it have enough juice for a practice setup?

    2. If I buy a poweramp can I use the lineout on the B-100 as a temporary preamp? (As you may have guessed I will be adding things in stages.)

    3. There are 2 dinky looking wires going from the "box" to the cabinet. Surely these are not carrying the amplified signal to the 15" speaker?!?! They are VERY thin, but there are no other wires going into the cabinet to indicate a seperate amplifier. I wouldn't know what to look for on the circuit board as far as ID'ing the amp circuitry.
  2. Put your amp back together, buy a book on amp repair and read it from cover to cover. If you couldn't begin to identify the simple circuitry on the PC board, you have no business poking around inside that amp. That's how stupid people get themselves electrocuted. Do you want to win a Darwin Award?
    I apologize for the harsh language, but Jesus, use your head.
  3. K-Frog


    Feb 6, 2002
    Camden, AR, USA
    What he said..

    and then

    1) yes, I used a 100 watt Yamaha head for years with a 410 cab. You won't do stadiums with it, but practice should be fine. I've done this with a Fender combo with good results.

    2) yes

    3) those most likely ARE your speaker leads.
  4. FuturePrimitive

    FuturePrimitive Supporting Member

    Nov 14, 2000
    Rochester, NY
    Relax, I do have enough sense to not poke around in a circuit board full of capacitors. My motive was to determine it the box was a wholly contained "rackable" unit, not to determine what each electronic component did.

    Thanks for answering my questions K-Frog.
  5. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Those little wires are your speaker leads...a 100 watt amp only supplies 5 amps to a 4 ohm load (which the B100R speaker is). Don't need much wire to safely carry that much current...and you generally never run your amp at continuous full power.

    If your Avatar cabinet is 8 ohms (the impedance that I'd recommend) you'll get less than 100 watts out of your Ampeg...but that's OK.

    You'd be wise not to hack around inside of your amp a shame to make a simple mistake and have no amp...

    MAJOR METAL HARVESTER OF SORROW Staff Member Supporting Member

    I have a B100R arent they great nice warm round tones. Does the cardboard in your ports ever slip what do you do. have fun with the amp:)
  7. cb56


    Jul 2, 2000
    Central Illinois

    "Don't worry, this gun's not loaded."
    Terry Kath