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Hartke 3500 Schematic or help

Discussion in 'Amps and Cabs [BG]' started by quartermoonpro, Oct 7, 2004.

  1. Hi,
    I've got a hartke 3500 amp with a broken main volume pot. Does anyone have a schematic for this amp or perhaps the digikey number or such for the replacement main volume pot? would I be better off just ordering a replacement from Samson?
    Thanks in Advance.
  2. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    I have the schematic for the HA5000 and HA7000, it has the same preamp as your amp...but I can't post it because it's in PDF format.

    Anyway, the solid-state and tube preamp gain controls are 50Kohm B taper (linear?) (50KB) pots, the Master volume is a 10KB pot. All that would be marked on the back of it...

    You should look at the remains of the exisiting part to make sure that you buy one that will fit in the printed circuit board.

    Have fun!!!
  3. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Check Digikey and Mouser for parts. It might be worthwhile to call Samson too... especially if you lost the knob when the pot broke off...
  4. Thanks for your help. :)

    Looks like I'll be going to Samson for the part. No biggie really. While I"ve got it apart, I'll be checking for those cold solder joints, hopefully it doesn't have any. (crossing fingers)

  5. craigers2


    Sep 26, 2001
    i'm not trying to hijack your thread, but i also have a 3500.

    on my last gig, i turned it on and the lights on the EQ no longer lit up. the EQ still worked fine, just no red lights.

    any ideas?
  6. b-ace!


    Jul 15, 2004

    try downloading the 3500 manual off www.hartke.com.
  7. The manual simply has a block diagram and not the schematics, at least as far as I could tell. But I appreciate the tip anyways.

    As far as the LED thing with the EQ, my guess would be a loose or broken wire that feeds the LED's. I believe it's a ribbon type connecter cable.
  8. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    I tend to agree with that...the LEDs are powered by the 10 Vdc heater circuit for the tube. If the tube section of the preamp still works, it's probably a connection at the edge of the circuit board.

    As for cold solder joints, I bought my 5000 used, it works fine (AKAIK), when I opened it up to clean it out and look around inside, I found one IC chip that was barely inserted into the board. If I ever get around to it, I may pull out the preamp board and check all the solder joints out.
  9. jgsbass


    May 28, 2003
    Floral Park, NY
    The LEDs on the EQ tend to go out when one or two become loose. Make sure they are all pushed in to their sockets. I am an ex owner of a 3500. Too many things went wrong with this amp physically to be considered a reliable amp. Not too bad a sound for the money but its put together.....Cheap!
  10. craigers2


    Sep 26, 2001
    i really haven't had too many problems with mine. i've owned the thing for close to 10 years and have played hundreds of gigs with it. i think it's a great amp for the money, and it has been very dependable up until the last few months.