Hartke 5000 help ?

yeti195 · 04-13-2008, 05:26 PM

Hello everyone, I just found this forum. There seems to be a lot of good information here, and I'm glad I found it.

Here's my question that brought me here.

I have a Hartke 5000 bass amp head that is needing some help. It all works great in mono mode, but as soon as it's switched to bi-amp mode the high output is very distorted and sounds like a blown speaker. Again in mono mode all four outputs sound great. The direct out also works great in both modes.

Could someone please help me with a good starting point for troubleshooting, and maybe supply me with a schematic?

I know just enough about electronics to be dangerous, but I do have great soldering skills. I like being able to at least try to fix my own stuff, because I use it as a learning experience. Using the web and forums like this I have been able to fix a few amps now, and am very thankful for any help offered.

Enzo · 04-13-2008, 10:54 PM

If biamp high sounds crappy, what does biamp low sound like?

I'd say if the powr amps aer OK< then ther is something wrong in the crossover circuit or the output driver for thjose biamp output lines. First place I'd look would be at the output pins of all the op amps looking for DC offset. Several volts, not a few millivolts.

yeti195 · 04-14-2008, 11:30 PM

Hello, and thank you for the reply.

In bi-amp, the low sounds fine. The problem is just on bi-amp high. I checked the voltage on the out puts of all the opamps. On IC203 I read 14.58 vdc on pin 1. Is this correct?

Thanks again for the help.

Enzo · 04-15-2008, 07:56 AM

I don't see that section on the schematics. if it is an unused section then that would be OK. if it is in the signal path, then it is not OK. if the board is out, op amp UCs cost about 30 cents, I'd swap it out just to find out.

emenelton · 04-24-2008, 07:38 PM

I have a 5000. My amp sounded like the failure you described. The biamp/mono switch on the back went bad. Try moving the switch around while passing a signal through the amp, see if the sound is affected. The technician initially sprayed cleaner into the switch, which helped only briefly. I ended up having the switch replaced and the problem disappeared.

The audio does pass through that switch.

Hope that helps.

04-13-2008, 05:26 PM	#1
yeti195 Junior Member Join Date: Apr 2008 Location: Springfield, MO Posts: 2	Hartke 5000 help ? Hello everyone, I just found this forum. There seems to be a lot of good information here, and I'm glad I found it. Here's my question that brought me here. I have a Hartke 5000 bass amp head that is needing some help. It all works great in mono mode, but as soon as it's switched to bi-amp mode the high output is very distorted and sounds like a blown speaker. Again in mono mode all four outputs sound great. The direct out also works great in both modes. Could someone please help me with a good starting point for troubleshooting, and maybe supply me with a schematic? I know just enough about electronics to be dangerous, but I do have great soldering skills. I like being able to at least try to fix my own stuff, because I use it as a learning experience. Using the web and forums like this I have been able to fix a few amps now, and am very thankful for any help offered.

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04-13-2008, 10:54 PM	#2
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,366	If biamp high sounds crappy, what does biamp low sound like? I'd say if the powr amps aer OK< then ther is something wrong in the crossover circuit or the output driver for thjose biamp output lines. First place I'd look would be at the output pins of all the op amps looking for DC offset. Several volts, not a few millivolts.

04-14-2008, 11:30 PM	#3
yeti195 Junior Member Join Date: Apr 2008 Location: Springfield, MO Posts: 2	Hello, and thank you for the reply. In bi-amp, the low sounds fine. The problem is just on bi-amp high. I checked the voltage on the out puts of all the opamps. On IC203 I read 14.58 vdc on pin 1. Is this correct? Thanks again for the help.

04-15-2008, 07:56 AM	#4
Enzo Senior Member Join Date: May 2006 Location: Lansing, Michigan, USA Posts: 10,366	I don't see that section on the schematics. if it is an unused section then that would be OK. if it is in the signal path, then it is not OK. if the board is out, op amp UCs cost about 30 cents, I'd swap it out just to find out.

04-24-2008, 07:38 PM	#5
emenelton Junior Member Join Date: Apr 2008 Posts: 1	I have a 5000. My amp sounded like the failure you described. The biamp/mono switch on the back went bad. Try moving the switch around while passing a signal through the amp, see if the sound is affected. The technician initially sprayed cleaner into the switch, which helped only briefly. I ended up having the switch replaced and the problem disappeared. The audio does pass through that switch. Hope that helps.

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