Poorly Hartke HA3500

[TenLetters]

I have an old style Hartke HA3500 which has been well used for a good 6-7 years with no trouble at all. I have owned it for 5 of those but knew the previous owner and there were never any problems untill recently....

Basically when i turn the amp on everything powers up fine but the output is barely audible and sounds farty. Turning up the master has little to no effect on the volume of the 'noise'. If I give the head a good bang it seems to work fine for the rest of the day even after being turned off and on again. It seems to happen after being left for a while unplayed which at the moment is quite often as i dont use it as my main practice amp.

I assume from this that it is some kind of loose solder or something but really dont have the minerals to go snooping around when electronics really are not my thing. I change the tube in the pre-amp not so long ago and that didnt do a great deal not that i really expected it too.

I dont really want to go on banging my amp every time I have a rehersal that requires it as im sure thats not going to do it a lot of good in the long run.

Any ideas or advice/ things for me to check would be much appreciated.

Cheers, Adam

[Alien]

Yeah, sounds like a dry joint to me. It's probably in the power amp as that's where all the heat comes from.

If you don't feel confident to do it yourself, have a look [url="http://basschat.co.uk/index.php?showtopic=198"]HERE[/url] for an amp tech near you.

A

[ped]

Had exactly the same issue with mine mate, I ended up having to sell in the end anyway but the buyer agreed it was a dry solder joint and fixed it himself eventually. Great amplifiers when they work!

Cheers
ped

[DHA]

[quote name='TenLetters' post='410618' date='Feb 15 2009, 11:38 PM']I have an old style Hartke HA3500 which has been well used for a good 6-7 years with no trouble at all. I have owned it for 5 of those but knew the previous owner and there were never any problems untill recently....

Basically when i turn the amp on everything powers up fine but the output is barely audible and sounds farty. Turning up the master has little to no effect on the volume of the 'noise'. If I give the head a good bang it seems to work fine for the rest of the day even after being turned off and on again. It seems to happen after being left for a while unplayed which at the moment is quite often as i dont use it as my main practice amp.

I assume from this that it is some kind of loose solder or something but really dont have the minerals to go snooping around when electronics really are not my thing. I change the tube in the pre-amp not so long ago and that didnt do a great deal not that i really expected it too.

I dont really want to go on banging my amp every time I have a rehersal that requires it as im sure thats not going to do it a lot of good in the long run.

Any ideas or advice/ things for me to check would be much appreciated.

Cheers, Adam[/quote]

Hi Adam,

Yes I would say it's a dry joint. Find a techie near you as it should not cost that much to fix.

Dave

[TheRev]

[quote name='ped' post='410641' date='Feb 15 2009, 11:55 PM']Had exactly the same issue with mine mate, I ended up having to sell in the end anyway but the buyer agreed it was a dry solder joint and fixed it himself eventually. Great amplifiers when they work!

Cheers
ped[/quote]


That was me!

By way of an update though, the problem hasn't completely gone away....

Initially, my repair bloke believed the problem lay with the FX wet/dry mix knob on the back. he replaced it and the issue was indeed solved for a while. After a year or so later I was back to thumping the bloody thing to get it going. I still think the problem is dry joints but in the speaker out jack sockets - giving them a wiggle seemed to produce more output and less crackling. I moved to a Markbass head (I went lightweight) soon after so I never got round to replacing the speaker sockets to see if they were indeed the problem.

[Guest MoJo]

[quote name='TenLetters' post='410618' date='Feb 15 2009, 11:38 PM']If I give the head a good bang it seems to work fine

I change the tube in the pre-amp not so long ago[/quote]

Exactly the same thing happened to me after changing the pre-amp valve in my HA2000. Turned out to be a loose screw on the chassis. Take the lid off the amp and just check all the little screws on the chassis holding the circuit boards in. Sounds daft, I know, but it cured the problem.

[TenLetters]

Thanks for all your thoughts. I have not been able to try any thing out yet as i have been manic recently but sure i can get it sorted by checking these things when i have time.

Cheers