pantherairsoft Posted December 6, 2011 Share Posted December 6, 2011 Hey guys, My Crown XTI1000 power amp is on its way back to crown due to a faulty display board. I don't own a spare amp, but there was a 2nd hand Hartke HA4000 in our works store room (I work for a company similar to Cash Convertors), which I was able to 'borrow' until my power amp comes back. Yay I thought... Got to the studio today, plugged in and powered on an while it 'works' the volume pot is very loud and crackly - a blast of switch cleaner I'm sure will sort it. Worse though, there seems to be the occasional crackle in sound when not touching the knobs, followed buy VERY loud pops and/or bangs - these are amplified higher than the volum of the bass signal. The pops etc do not seem to be related to a specific connection as happen on both input jacks and are not related to the wiggling of a cable etc... Just seem to be when it wants. It can be quiet for a minute or two, then bang 3 or 4 times. I've opene it up and can't see any dry joints etc, everything seems intact. I'll blast some switch cleaner onto the volume pot and in the jack sockets but I'm not convinced it'll help... I tried a couple of different leads as well to rule that out. The only non PC thing I was doing is not using a regular speaker cable. This was because the amp only has jack outs an I only own speakon to speakon cables. I used a high quality instrument jack-jack lead with a jack to speakon adapter on one end. The cable and adapter are usually used for other things and both perform fine so I can't see this being related to the issue, but is worth noting for completions sake. Other than switch cleaner... Anyone have any ideas what would cause this. The bangs are very loud and aggressive and do not sound at all healthy for the cab. In between the bangs and occasional ceackle the signal sounds perfectly clean. I'm eager to get this working as I'm totally without an amp! Thanks Shep UPDATE: Just noticed that with no instrument/nothing plugged into the inputs the noises do not seem to happen, nor does the volume pot crackle! So maybe it is related to the input sockets and switch cleaner may well work!? Quote Link to comment Share on other sites More sharing options...
icastle Posted December 7, 2011 Share Posted December 7, 2011 Don't think it's something you'll fix with switch cleaner. Sounds more like a bad joint somewhere around the jack socket to me. Hartke were notorious for poor quality PCB manufacture a while back. They're easy enough to fix but it takes a little time, patience and a few soldering skills. Quote Link to comment Share on other sites More sharing options...
Slipperydick Posted December 7, 2011 Share Posted December 7, 2011 As has been said, Hartke are prone to dry Joints. AT YOUR OWN RISK, and only if you feel competent to do it. With one hand in your pocket, the amp powered up and turned on, and preferably a signal feeding it from yer iPod or something, but NOT an earthed Bass or guitar,, Try poking and tapping around the PCBs with something insulated, like a plastic knitting needle or the handle of a plastic knife. If its a dry joint you should be able to make the fault happen, and isolate the area. Also might be worth trying warming the innards up with a hairdryer. Quote Link to comment Share on other sites More sharing options...
pantherairsoft Posted December 7, 2011 Author Share Posted December 7, 2011 Thanks guys. I think I may write this one off then. It's not my call to get it repaired and was only 'borrowing' it for a few days... ... Priority now should be to borrow a different amp! Quote Link to comment Share on other sites More sharing options...
pantherairsoft Posted December 7, 2011 Author Share Posted December 7, 2011 Guys, If we think it's related to the input, could I still use my EBS Pre amp connected to the effects return to treat the Hartke as a power amp? Quote Link to comment Share on other sites More sharing options...
Adrenochrome Posted December 7, 2011 Share Posted December 7, 2011 [quote name='pantherairsoft' timestamp='1323252892' post='1460981'] Guys, If we think it's related to the input, could I still use my EBS Pre amp connected to the effects return to treat the Hartke as a power amp? [/quote] Probably wouldn't hurt to try that. Quote Link to comment Share on other sites More sharing options...
pantherairsoft Posted December 7, 2011 Author Share Posted December 7, 2011 [quote name='Adrenochrome' timestamp='1323256053' post='1461021'] Probably wouldn't hurt to try that. [/quote] Good enough for me. If I get blown up it's officially your fault now lol Quote Link to comment Share on other sites More sharing options...
icastle Posted December 7, 2011 Share Posted December 7, 2011 Well if the amp works fine just by using the return socket and your EBS then that provides another indication that the preamp on the Hartke is unhappy. Depends on the sort of values involved here, but if your company has bought a knackered amp then they're stuck with it. Make them an offer in the 'scrap value' sort of range, sort out the duff joints and you've got a really reliable standby for a few quid. I've got an old HA3000 I keep for exactly that reason that had the same problems you describe - took me a couple of hours to desolder and resolder the cr*p joints. Quote Link to comment Share on other sites More sharing options...
pantherairsoft Posted December 7, 2011 Author Share Posted December 7, 2011 Just back from the studio. Switch cleaner has sorted the crackly volume pot - all gone. Switch cleaner in the jack sockets seems to of done some goo there as well as the crackles bangs and pops are slightly quieter and certainly less frequent - though this could be coincidence. Oddly though I could not recreate the issue playing my iPod through the amp, only with an instrument connected. Using it as a power amp run by my EBS pre, it performs perfectly! The Harke does nothing in this setting and the volume control does not work (assume that's pre not post) but it allows me to get decent volume and tone from my EBS. I have only tested this with a clean signal and won't get to throw my full sub bass doom at it until tomorrow and hope it holds up OK. So, definitely the pre and likely a dry joint around the input as you suspected. I'll have a hunt for that when I'm feeling brave! Quote Link to comment Share on other sites More sharing options...
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