Hi all - hoping for some support or ideas…
I am using a BHK preamp. Sounds great. But when music is not playing - or in mute - for 15-30 mins - the preamp shuts itself off.
Not sure what the deal is.
I just bought the preamp on used market.
Ideas?
Thanks all!!
Terry
Sounds like it might be over heating? What’s its ventilation situation?
Hey Paul! Thanks for writing. There’s about 3 inches above the unit. And it’s sitting on an isolation platform. Does it also ventilate from below…?
From what I can see, in your picture, you’re blocking the vents on bottom completely. Yes all vents must be clear so convection can remove the heat from the unit.
Also….when listening to music for extended periods …eg greater than 90 minutes, the preamp works great - and does not shutdown.
Thanks George. I added some spacers. Will see if that helps…….but seems weird that it doesn’t shutdown when music is playing for hours - but DOES shutdown when no signal passing through.
Going to test the spacer theory….and stop the music and see what happens.
I agree, this appears odd.
2 to 3 inches above the unit with open sides is sufficient for ventilation.
Agreed TJ. Opening up the bottom vents is a free and quick test. Not passing a signal could be using a circuit not in use when playing music. As Paul mentioned it could be a thermal issue. If you’re comfortable with troubleshooting you could open her up and go at it with a heat gun and freeze spray.
Well….its been about 30mins and the BHK preamp is still powered up. Hopefully that’s all it was - a circulation / venting issue from below.
Thanks fellas!
I’ll write again if anything changes.
Peace out.
TJ
The reason the preamp was not shutting down when playing music is it runs in full class A. Class A generates the most heat at idle. When music is playing the power is used to provide music instead of creating heat. Don’t get me wrong it still creates heat but at a lower level. Never obstruct ventilation.
Very interesting. And helpful.
Yes, thanks again everyone.
I see said the blind man; Makes perfect sense. looks like the problem has been solved. Gotta love the K.I.S.S. approach.
Please note that this type of PS Audio chassis does not have side vents. Those are solid castings.
