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Hartke HA3500 problems

Discussion in 'Amps and Cabs [BG]' started by nfgrufio, Jan 24, 2005.

  1. nfgrufio


    Jan 22, 2005
    hey, can anybody tell me why my amp cuts out after playing at a certain volume, rather high volume, for about 3 to 4 seconds?
  2. andruca


    Mar 31, 2004
    Madrid (Spain)
    This is most likely a heat problem. I had it with the same amp one night. It was after 3 hours of use with a spotlight 3 feet away of it pointing directly at the head's venting ports (and it wasn't racked back then). After 2 previous bands played with it, I stepped on and I raised volume substantially. The amp couldn't stand it anymore and I got three of these cuts during our 45 minute show. Good thing is preamp still works and so does the DI out (so no bass interruption on the house PA). The guys at Samson's support told me it's a protection the amp has when it overheats. I confirmed this by applying a hair dryer on one of the back ports of the amp (the one where you see the fan). I could hear the relay (the same you hear after power on, when output to cabs is connected) disconnecting puwer output and reconnecting it shortly after. Although this was an extreme heat situation I didn't want to take chances so I changed the fan (I think it's 24V) for one with double its thermal capacity and this never happened again, but I was careful not to expose it to any source of direct heat. No big deal at all! Hope this helps (and calms the anxiety this problems generate). Good luck!

  3. DWBass

    DWBass The Funkfather

    If you have to play at very high volume to be heard or to get your 'sound' you need more power than the 350w you have now. Is your cab 4 or 8 ohms? If it's 8, you are not getting the full 350w! You need a 4 ohm load to max out your amp. If your cab is indeed 4 ohms, you need more power. Time to upgrade!
  4. craigers2


    Sep 26, 2001
    I have the same amp and have recently started to have the same problems. The amp just overheats and it shuts off for about 3 seconds and pops right back on. This was not really an issue when I was only powering one 8ohm cab. Within the last year, I added a second 8ohm cab and started having the overheating issues.

    I took my amp into my repair guy and he gave it a really good cleaning. He told me that there was a lot of dirt and dust. This seemed to help the situation a little bit, but I have had it happen once or twice since my repair guy looked at it.

    Now I'm looking for a new amp that can has some more power. It looks like the 3500 just isn't cutting it anymore.
  5. DWBass

    DWBass The Funkfather

    Look into putting a new fan in it. I'm finding this weird because the 2 Hartke amps I own barely get lukewarm when I play. If yours is getting hot, it's either not cooling, overloaded due to high volume/impedance issues or something else.
  6. cyrilbcyril


    Apr 8, 2007
    I've got the same experience, but couldn't figure out what it was. The protection IC from Toshiba cuts the main relay if I turn the volume too much. Just before it cuts there are some cracking/clicks. I opened the monster, and tried to determine if it was due to overheating. It looks it isn't: putting my finger on the heatsink and directly on the thermistors while it is happening, the temperature doesn't seem to exceed 40C, which is a very reasonable temperature. I guess case temperature should exceed 80-110C before the thermal cut off trips. I tried to shake it to see if maybe one solder joint was loosy, couldn't replicate the failure. I have no clue what it could be else. Maybe the IC from Toshiba is screwed up ? Maybe this is the tube ( although it seems the failure is correlated with the amplification and the tube is in the pre-amp section)....

  7. cyrilbcyril


    Apr 8, 2007
    One more thing I did : I tweaked the DC / BIAS potentiometers in the amp section, no effect at all, still the cut-off after a couple of seconds !!
  8. SonofDadBass


    Sep 12, 2005
    New Jersey
    I have a Hartke HA4000 which I purchased (used). I got it at a good price and was enthusiastic about it with a seemingly good amount of watts for the cash I paid.

    Anyway, the amp would continually go into protect mode, usually in the middle of a song. On my model, protect mode is indicated by a yellow light (different than clip, which is red). When the light came on, the amp would cease producing sound for a few seconds.

    After this happened a few times, although I was tempted to throw it off stage, I brought it to my local music repair shop. They fixed it for a decent price. I don't recall what the problem was, unfortunately. I should be able to check my records and find out the diagnosis.


    Even now that I consider it to be in good working condition, I think the amount of volume it put into 8ohms is weak, I find it to be more sensitive than other heads. When going head-to-head (get it) with other amps I find it clips easier and at lower volumes.

    I recommend trying a full ohm load for the head and see what occurs. Make sure you are using appropriate speaker cables. Also, try turning down the sub-bass, I believe Hartke calls it D-Bass.

    There are fans of Hartke and haters too. I am not sure what I am yet.

    Hope this helps a little,

  9. Musician1


    Nov 7, 2015
    Hello!! This is bryan again. I already post a reply on this experiences. My HA3500 exhibits the same behavior. "evil crackling / popping" leading to no sound with the amps still on. I identified two components navy green in color with the following number SAM WHA HM 85C (M)100wv4,700uf. I don't know what are they but I think they are the thermistors mentioned previously by CYRIL. When I tapped these two components with my finger the amp came back to life but after a few minutes is dead again. Its crazy but seems to be that too many HA3500 amps got the same sickness.

    Any doctor that can give us some help>>> HELP HELP HELP.
  10. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Yes, you are correct that you don't know what those things are that you tapped. (hint, they are not thermistors)

    Yes I can give you good advice. Since you don't know what those parts do, you can get your amp fixed by taking it to a qualified repair technician who does know what all those parts do. Not only will you get your amp properly repaired, it will be safer than poking around inside the amp with the power on.
    BassmanPaul likes this.
  11. BassmanPaul

    BassmanPaul Gold Supporting Member

    Aug 25, 2007
    Toronto Ontario Canada
    Never poke around inside any amplifier with your finger. It's a very good way to hurt yourself!!

    Also, as aged horse advised, if you don't know the difference between an electrolytic capacitor and a thermistor take the amp to a tech. If you continue to mess around inside your amplifier you'll likely turn $50 repair into a $500 one. Just 'cos you own the amp doesn't make it advisable to try and fix it.
    Last edited: Nov 8, 2015
  12. raybone


    Jul 14, 2006
    A.C Jersey
    Just a thought, make sure the fan is blowing air out. I had the fan replaced on my 20 year old ha3500 and it started with thermal shutdown issues. Ended up being the fan was drawing in instead of blowing out air ( installed backwards). Switched it around and all is good again.