Hartke LH500 Bass Amp Issues

Discussion in 'Amps and Cabs [BG]' started by Terry Sudholt, Apr 16, 2012.

  1. Terry Sudholt

    Terry Sudholt Guest

    Apr 16, 2012
    St. Peters, MO
    I purchased a Hartke LH500 bass amp in February 2011 and am very pleased with the sound it produces coupled with my 500W Avatar B210 Neo speaker cabinet and Fender Jazz bass guitar. It has an incredibly rich tone that fills the room with great bass presence whether I’m playing rock, blues, jazz, or country in an electric or acoustic environment. However, I have had functional issues with the amp that are driving me nuts.

    When I turn the amp on, it powers up and the fans kick on immediately, but it does not truly kick on and produce sound until about 15 – 20 seconds later. I have been advised that this is normal and, although it took a bit to get used to, I have accepted that as the nature of a high-end amp.

    In December 2011, I began having issues with the power cutting off unexpectedly. I replaced the AC Inlet in the rear of the amp and have had no problems with the amp powering up since. However…

    Over the past couple of months, the amp has begun cutting on and off intermittently, not the power, but the sound itself. The amp powers on, the fans kick on immediately, and the sound comes on about 15 – 20 seconds later, but the sound turns off after about 10 seconds, comes back on a couple minutes later, then turns off about 10 minutes after that. The sound continues to cycle on & off intermittently, although the power, lights, and fans remain on throughout.

    I set up at a gig Saturday night and powered up the amp about an hour before the show. It was noisy in the room and I couldn’t hear whether the sound was cutting off or not, but every time I checked it, it was on and sounded great.

    When we took the stage, I plucked the strings while it was in the guitar stand and it was working fine. I picked up the guitar, put the strap over my head, and plucked the strings… no sound. Fortunately I had brought a backup amp and had it plugged in and ready to go. I switched to my 1970 Peavey amp and it worked great. The Peavey had plenty of power, but not the rich tone and presence of the Hartke. Not to mention the frustration of having to use a 41 year old amp because I can no longer rely on my relatively new Hartke amp.

    If anyone has any ideas on how to address this issue, they would be much appreciated. There are a couple of good Hartke service facilities here in the St. Louis area, but unfortunately, I am a couple months beyond the 1-year warrantee period, and they have a 2 to 3 week backlog before they can look at it. Hopefully, someone has experienced a similar issue in the past and can offer some advice.


  2. Larry Hartke

    Larry Hartke

    Feb 27, 2010
    Hartke Systems
    No worries, just call my service manager Joe Antonelli at 1-800-328-2882 (New York) and he will get you up and running. The fans do come on at startup and the delayed audio start up time is just the pre-amp tube warming up and that is completely normal. It might even be that a bad tube is causing your problem. Give Joe a call, he just got back from vacation today so he's probably pretty busy, but leave a message if you get his voicemail, tell him I sent you and he will call you back.
    Don’t worry about the warranty; we’ll fix it for you!
    If you need further help you can always reach me at 201-452-4960 Cell or [email protected]
  3. And this folk... is why Hartke is the BEST!

    Larry, I am looking forward to rockin out this summer with my new LH1000/HX410 stack. Now if that shipment can just come a LITTLE faster. :bag:
  4. jjk2007

    jjk2007 Supporting Member

    Apr 16, 2008
    Austin, TX
    +1 for Hartke CS.

    And logic, that's the rig I run myself. You will enjoy!! :bassist:
  5. Terry Sudholt

    Terry Sudholt Guest

    Apr 16, 2012
    St. Peters, MO
    Thanks for the quick response Larry. Much appreciated. I left a message for Joe this afternoon.
  6. DirkJan Wassink

    DirkJan Wassink Guest

    May 8, 2012
    This exaclty explains the problem I am having with my amp. Is there any way I can fix this?
    I saw in a lot of threads that its suggested to call this Joe Antonelli, But I live in The Netherlands so that really isn't that much of a option to me.
    This is also the second time this amp broke down on me the first time the transformer had a short circuit and I got a new one from Hartke them self, but it took the store where I got it almost 2 months to actually send it so I had to play gigs with a amp from a friend of mine. I don't actually want to do this again.

    Any advice on what to do?
  7. Larry Hartke

    Larry Hartke

    Feb 27, 2010
    Hartke Systems
    Hey DirkJan,

    You can contact my distributor in the Netherlands and they should be able to help you out. If you need further help just e-mail me at [email protected]

    Total Sonic B.V.
    Boekweitstraat 1B
    GK Nieuw-Vennep

    Phone: +0252 629 340
    Fax: +0252 629 364

    Website: http://www.totalsonic.nl/
    Email: [email protected]

    Thanks for playing Hartke!
  8. Freakin NINJA! Yet another reason to love my Hartke gear.

    SWERSH Guest

    Oct 12, 2012
    Moscow, Russia

    I would like to share the information, that, I hope, will be useful for Hartke LH500/LH1000 users.

    I bought some time ago LH500 amplifier. It's really good amplifier.
    However, I've found that my exemplar generates very big noise, even when volume control potentiometer is set to a minimum. My analysis of reasons showed that C302 and C306 polar capacitors in power amplifier are used in inverted polarity. I've opened scheme and found that these capacitors are mounted so in accordance with scheme. In my opinion, it's not correctly, because polar capacitors are very sensitive to polarity.
    If you open electrical scheme, you will see that output of amplifier has (should be tuned) zero potential relatively of ground. A current to a base of Q067 transistor provides some drop of potential (about 0.1-0.2V) on R316 resistor. Therefore, the bases of G067 and G302 transistors always have some negative potentials relatively of ground (-0.1...-0.2 V), but on the scheme the polarity of C302 and C306 capacitors are marked so that they should be set in inverse polarity. Manufacturer sets the capacitors in accordance with scheme, i.e. also in inverse polarity. As a result, some leakage currents through these capacitors may take place that generate big noise in my amplifier. Other exemplars may have much smaller noise but in any case life of these capacitors may be very short due to inverse polarity.
    I've replaced these capacitors (C302 and C306) by new ones, having mounted them in correct polarity: "+" - to direction of "ground" and "-" - to direction bases of transistors. Also, I've replaced nonpolar capacitor C304 by polar one, also "+" - to a ground and "-"- to the bases of the transistors.
    Now, after these corrections and a tuning of 0 V on output of amplifier by the SVR301 resistor, all polarities and voltages are true, and any noise is absent in practice at all.
    Now, I can hear just small noise of tube but only in maximal position of volume control potentiometer.

    I tried to inform Larry Hartke about my find, but didn't get any reply.
    I hope, my remark will be useful for all users of this amplifier.

    Finally, I would like to say that in spite of the mentioned remark, the LH500/1000 amplifier is very good. I am satisfied completely by its work and recommend it to all bassists.

    Best regards,
    Polardog likes this.
  10. pedroims


    Dec 19, 2007
    I have own two LH500 and I dont remember any noise at all, neither practice nor gig level. I would like to heard what Larry has to say about.
  11. will33


    May 22, 2006
    How cool is that? ^^

    Way to go, Sergey.
  12. SWERSH

    SWERSH Guest

    Oct 12, 2012
    Moscow, Russia
    I said already that it's not necessarily that the noise should be in each exemplar. No of course. Especially, if amplifier is new. However, after some time (maybe even after very long time), such noise may take place because these capacitors may be failed.
  13. Show N Tell

    Show N Tell Guest

    Jul 25, 2013
    I used to have a Hartke HA7000 head that powered a 410.5xl and 115xl cabs (still have the cabs). I was in love with the sound it had but after a while the amp started having a flanger type swishing sound to it when I would stop playing. I talked to the local authorized repair man in town and he said he could fix it but then he found out I used to bang his wife (before he knew her) and i didn't trust him with it so I traded it for a peavey t-max. Now they don't make them anymore! If I had known then that I could have talked to Larry Hartke myself and got it fixed i would have never gotten rid of it!