Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Problem with Goliath II, help!

Discussion in 'Amps and Cabs [BG]' started by klocwerk, Jan 27, 2006.


  1. klocwerk

    klocwerk

    May 19, 2005
    Somerville, MA
    I have a Goliath II that I got cheap because the fuse (light bulb) was blown, and the guy didn't know if the horn was good or not 'cause he'd never replaced the fuse.
    Got it a few months ago, played it as-is since then. My hartke 7000 puts out a pretty crispy tone, so I didn't miss the horn.

    I finally located a replacement for the fuse in question, popped it in, and Volia!
    Nothing.

    - If I smack a 9v against the terminals of the horn I get some static, so I know the horn isn't totally dead.
    - If I wire the horn directly to the inputs it just puts out lots of fuzz.
    - If I wire the horn behind the first electronic bit (big yellow barrel, doesn't look like a cap, possibly resistor) I get nothing.

    - The circuit goes about like this:
    Input splits, half wired directly to woofers (4x10, 4 ohms), other half goes into treble crossover for horn.
    -> two yellow barrels (series)
    -> wire inductor coil
    -> big 'ole level knob (pot)
    -> horn

    1. Inductor coil wired in series, would give us a 1st order band-pass filter.
    2. If inductor is wired in parallel as a high-pass, yellow barrels must be caps a-la a second order high-pass.
    (http://www.termpro.com/articles/xover2.html)

    This cab lives at my practice space, so I'm taking my multimeter and some test leads with me next time I go over there, but I'd LOVE any info you guys can give me. I have no idea what those yellow barrels are (I'll get photos), and I can't figure out why the horn wired directly to the inputs was fuzzing so badly when the woofers were chillin quietly.

    :help: :help: :help: :help: :help:
     
  2. pickles

    pickles Supporting Member

    Mar 23, 2000
    Ventura, CA
    You might be able to buy a new crossover unit from SWR, I don't imagine it has changed much over the years. The barrels are likely to be caps, but the folks at any good electronics shop could tell you. If you decide to rebuild the crossover, I'd reccomend:

    1) remove it from the cab and get it on your desk.
    2) take some high res photos.
    3) carefully unsolder and remove the components
    4) take the components down to an elecronics shop and match them exactly.
    5) reasseble.

    But buying a new crossover is probable a much better option.

    It'll be worth it, Goliath II is a GREAT cab.
     
  3. buzzbass

    buzzbass Shoo Shoo Retarded Flu !

    Apr 23, 2003
    NJ

    I had the same problem/symptoms with my Goliath II when I bought it used. Turned out I had to swap the horn itself and the big adjusting resistor(rheostat). Tuns out the horn was bad and took the fuse and resistor with it. Even after I got signal to the horn, all it did was crackle. YMMV
     
  4. klocwerk

    klocwerk

    May 19, 2005
    Somerville, MA
    Thanks for the info.
    I was afraid of that. DO you remember where you got the rheostat from?
     
  5. F.Y.I....Retail price for a Goliath III crossover assy. is $110 and if the horn is bad you can replace the diaphragm for about $25.
     
  6. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    it's worth it to consider that the horn and corssover are probably almost identical to that used in the eden cabs as the goliath 2 is almost an exact copy of the eden made goliath 1, which became the eden 410t. it might be cheaper to get a crossover or horn from eden, and perhaps from another source.
     
  7. klocwerk

    klocwerk

    May 19, 2005
    Somerville, MA
    Update!

    Pretty sure the horn is good. Took it out, took it apart, everything seems kosher there. Problem must be in the crossover, which is somewhat more problematic to take out easily and bring home, let alone test it.

    Did a bunch of research, looks like it's an 18db/octave crossover at 5khz, which would make it a third order xover. The horn is an 8ohm, although the cab tests at 4ohm. little weird, but whatever.
    Punched the numbers into a crossover calculator, came up with this.

    18db/octave, 5000hz @8ohms
    L3 - .38198 mHy (millihenries)
    C3 - 5.29206 mfd (microfarads)
    L4 - .12733 mHy
    C4 - 2.65399 mfd
    L5 - .19099 mHy
    C5 - 7.95798 mfd
    + --C4-----C5----\
               |              \
              L5              speaker
               |               /
    - -----------------/


    (fear my ascii art skizzilz!)


    And I still know nothing about what the pot/rheostat/variable-resistor specs are.