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Hafler P7000 runs 'hot' even at idle, normal?

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JoeKool

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I picked up this Hafler P7000, with the thought of maybe replacing my older P500's series amps, but it seems to run hotter even at idle, is this due to the more compact transnova design? I like the smaller form factor, but I am worried about the longivity of the unit with such heat generated. THe air blowing out the front at idle was about 110degrees. The older P500, and 505 were never that hot at idle. WOnder how hot it would get when I really pushed it.
Anyone familiar with the P7000 care to shed some light on this model?

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Re: Hafler P7000 runs 'hot' even at idle, normal? - STUART 07:10:22 02/09/05 (0)
Considering this amp draws 200watts at idle (2.3amps @ 120VAC)
and puts out 350watts into 8ohms and is a mosfet device..YEA
its gonna run hot at idle
This amps draws 470W/5.2amps @ 120VAC (1/8 power/8homs)
1100watts /12amps@120VAC/ full power into 8ohms.
NICE amp dood
I have a Hafler Mosfet amp and it runs hot idle as well
Dont sweat it....
I have a 4K Bedini class A amp that I cant run in the summer cause
its basically a heater in my living room.
I leave it run 24/7 in the winter and it helps heat the house.
:)
Re: Hafler P7000 runs 'hot' even at idle, normal? - Bob Lee (QSC) 14:31:06 01/31/05 (5)
Do you have access to an oscilloscope? If so, take a look at the outputs, with no signal into the amp. They should be very clean, both at zero volts. But I suspect that perhaps at least one channel on yours is oscillating. That would make it run hot even at idle.
- Re: Hafler P7000 runs 'hot' even at idle, normal? - JoeKool 17:27:53 01/31/05 (4)
  Thanks for the reply Bob, but I don't own an oscilloscope, just a Fluke DVM. I got it directly from the factory(Hafler) as a 'B' stock, so I would think they would have checked it out before sending it out. Or do they? Mhnnn...I have sent them an email but just haven't received a reply yet.
  - Re: Hafler P7000 runs 'hot' even at idle, normal? - Bob Lee (QSC) 08:43:25 02/04/05 (3)
    I should think they'd have checked it out, but there's always some possibility that something went wrong between then and when you got it.
    Another possibility might be an incorrect bias setting, causing higher than normal quiescent current to flow through the output transistors. I don't know how Hafler amps are biased, though.
    -Bob
    - Re: Hafler P7000 runs 'hot' even at idle, normal? - JoeKool 15:21:02 02/04/05 (2)
      Today I checked the bias and it was 435ma on the left channel and 425 on the right, the I reset them both down to 375ma which is less than the recommended 400ma. It seems to be running much cooler now.
      Thanks for the tips Bob. I am dissappointed by a lark of response from Hafler though.
      - Re: Hafler P7000 runs 'hot' even at idle, normal? - STUART 07:14:04 02/09/05 (1)
        
        In Reply to: Re: Hafler P7000 runs 'hot' even at idle, normal? posted by JoeKool on February 4, 2005 at 15:21:02:
        
        You shouldnt outa be messin with the bias setting when its set
        within spec
        Im tellin ya that this amp runs hot and its ok.......
        There are alot of amps that are class A/ B and they run hot to the
        touch at idle
        
        Re: Hafler P7000 runs 'hot' even at idle, normal? - JoeKool 22:52:17 02/12/05 (0)
        
        In Reply to: Re: Hafler P7000 runs 'hot' even at idle, normal? posted by STUART on February 9, 2005 at 07:14:04:
        
        Hey Stuart, thanks for responding, I actually did finally get to talk with Hafler Tech support and they did say that it does run hotter than their older designs, so I have set the bias at 400ma which is where they recommend it. Originally it was about 25-35 higher. It sure is a powerful amp.

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