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hartke 3500 problem

Discussion in 'Amps and Cabs [BG]' started by Berten, Aug 31, 2005.

  1. Berten


    Jun 6, 2002
    I was at rehearsel yesterday when my hartke 3500 head just stopt producing sounds.....

    I was using the 'passive' input with my active bass (warwick thumb) en really pushing the preamp section (to get a better sound). Suddenly the sound did dissepear for 2 seconds and then it came back. 2 Minutes later there was no sound at all!

    Could it be that the head became to hot? It is in a 2U flightcase so maybe the heat can't get away....

    I didn't have time to try it afterworth, so maybe it works again, but did anyone had the same problem?

    PS: when the amp stopt working I didn't hear a 'plop' or something. The sound just fell away....
  2. craigers2


    Sep 26, 2001
    I used to have a 3500 and it started to do the same thing. I took it to my amp repair guy and he did say that it was overheating. He gave the amp a good cleaning and that really seemed to help the problem.
  3. Rumblebee

    Rumblebee Guest

    Mar 16, 2005
    What cabs are you running under it? For the future, once you get the problem corrected at good amp tech, you could run it through some more efficient cabs. That way you may not need to push the amp so hard... I know my 3500 is a lot louder through better cabs. Just a thought.
  4. Berten


    Jun 6, 2002
    I have a peavey TX410 and a hartke transporter. Yesterday I was only using the peavey...

    But i wasn't pushing the amp, only the pre-amp, to get a better sound!
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    When you push the pre you are adding compression to the signal so even at the same apparant volume you're adding to the power content and that can lead to overheating. The 3500 will go into thermal protect mode with seemingly little provocation. Additional cooling usually does the trick. Periodic vacuuming doesn't hurt either.
  6. Berten


    Jun 6, 2002
    I was thinking/hoping that it was just an protection mode...but I looked in the manual yesterday and I could find anything about it.
    So it would be a better idea to take the amp out of the 2Unit flightcase and putting it in a bigger one, so there is room for some cool air.

    I will try my amp again to night and I hope it will work...I will let you know!
  7. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That wouldn't make much difference, the venting of the 3500 is through the rear of the chassis via the fan and the u shaped duct that houses the heatsink. If the heatsink or fan are dusty they won't shed heat well, and it the rear of the chassis is blocked so that all the fan does is recirculate hot air it's a problem. I find that a small portable fan blowing across the rear of the rack to provide a constant source of cool air works pretty well.
  8. RobertUI

    RobertUI Thumper Supporting Member

    Apr 7, 2005
    Herndon, VA - NoVa
    don't know if this applies, but i have the HA4000 and had a similar problem, and it actually turned out to be a fried cap in the clipping circuit. mine would run fine for about 15-20 minutes, and then it just wouldn't stay on. the clipping LED kept coming on though.

    sorry, i can't remember if the 3500 (this is what i use at our rehearsal studio) has this clipping LED or not. FWIW it was a pretty cheap repair.

  9. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    The 3500 doesn't have a clip LED. Mine usually went dead only at the end of a song, when I'd hit a chord and let it ring the power amp would cut out but I'd still hear it through the PA. 30 seconds later the thermistor would reset and I'd be good to go for the next song. Vacuuming out the dust once a month and the extra fan cured it. Pain in the rump, but better than cooking output transistors.
  10. Both the 2000 and the 3500 have a faulty ribbon cable that is notorious for going out. When that happens, basically you have to send it in for repair with Hartke. (Which I'm finding is damn near impossible.)

    My 2000 is going out now. It's completely unpredictale, so I can't rely on it for any situation.

    This may not be your problem, but something to think about
  11. Kael


    Dec 26, 2004
    Oklahoma City
    I had a 3500 that had a bad solder joint somewhere in it. Once it got hot and started shaking, it would cause the head to stop putting out sound. Took several trips to a local tech to isolate/fix the issue.
  12. Berten


    Jun 6, 2002
    Well...I tried my amp again yesterday...it's still dead!

    I opened it, but scince I know nothing about electronics I didn't see anything wrong about it...

    I tested it a bit: the preamp still works fine. I used a cable to connect the send-output to another amp and it work. Using the headphones-out of the other amp with the return-in of the hartke head resulted in no sound....

    I will take it to the shop where I bought and see what they can do...(The amp was new when I bought it and it's only 4 years old, so I hope that it be repairable...)
  13. tadawson


    Aug 24, 2005
    Lewisville, TX
    Frankly, I don't think that "non-repairable" is even possible. It is a question of 1) What will is cost. and 2) Does the guy looking at it have the mental firepower to do the repair. Seems to me lately that a lot of times the limiting factor is #2, and they would just rather sell you something new. I have looked at a fair amount of electronics that folks were told were "not repairable" and fixed them in under 30 minutes with a $5 part . . . . non repairable? Maybe by the moron who was looking at it, but not by someone who knew what was going on . . .

    <Rant off . . . >

    - Tim
  14. Berten


    Jun 6, 2002
    Well, my amp is fixed...one of my speakers had a short so I blew up the power amp! They had to change all of the transistors, but I works again!

    Total cost: 180 euro's! It's a lot for an amp of 500 euro's, but it is cheaper then buying a new head....
  15. Well, it is possible, and it's not always a case of repair-man-has-an-empty-skull syndrome - although, you do still have to be careful that you don't get duped by shrewd techos who will gladly play you for a sucker!

    Rant on a tangent follows;

    Often, particularly with older equipment, the spare parts are simply not available. Obviously, many parts are ubiquitous, but some are specialised - and once the stocks dry up, that's that. I've thrown out my share of unrepairable stuff at work because of this unfortunate situation.

    Another reason is uneconomical repair. If you can get the part, but the cost of the part is close to or more than the cost of a new unit, then the question has to be asked - is it worth repairing? This is often the case with gear that is very close to passing into the previous category.

    Still another one that pops up these days is to do with surface mount components. Some of the new electronics is just not designed to be repaired and falls apart at the first sign of a solder rework process. The boards are flimsy, or the chips are glued down as well as soldered. Sometimes, in high density circuits, the parts are so close together that you cannot work on one part without damaging a handful of other parts or destroying delicate copper tracks.

    So, think carefully before buying that fancy new class D bass amplifier!
  16. andruca


    Mar 31, 2004
    Madrid (Spain)
    I had the same problem with my old 3500 but the cause was not dust (I kept it always clean) but a 1000W stage-light lamp pointing directly at it (wasn't racked at that time). To prevent further inconveniences I changed the fan for a more modern one, that had double the original's thermal capacity (with little increase in power consumption -be careful with this! i wouldn't risk the circuit that feeds the DC for the fan by changing it for one that's too power hungry in comparison-). It never happened again. Normally, keeping it clean, racked and with free air running through the back of the head should work OK. When it's in heat-protect mode you can hear a relay cutting power to the speakers (DI out still works!). I checked this out by using a hair dryer through the fan's intake.