QSC amps PL-340 & PLX-1802 fan cooling noise

[Massilia]

Hi,

Already posted in Amplifiers/Solid state but perhaps it is here in PA that the question should be posted...


I would be interested in those QSC amps (PL-340, and possibly the PLX-1802).
This is class H amps with switched supplies.

In particular PL-340 is described as "the ultimate analog amp" by QSC. It seems indeed to have very good performances.

As I would often use it in domestical environment (on my tri-amped HR JBL system), a critical point for me is the fan cooling noise. I would like not to hear it at low electrical power (or when music is OFF), let say at 1m distance.

Do someone knows these amplifiers (in particular the PL-340 or its brother the PL-325), and could confirm me the lack of fan cooling noise at idle output level?

Thanks in advance

Bruno

 

[JonSnell Electronic]

The fan only works when hot. They are noisy as there is no need for a quiet fan in commercial amplifiers. Keeping cool is the main criteria.

 

[Massilia]

Thank you.

I understand the point you mention (They are noisy as there is no need for a quiet fan in commercial amplifiers. Keeping cool is the main criteria).

If the fan only works when hot, I guess it should be OK when the music is at <1W level (most of the time when used at home!) or particularly, when music is stopped.
I bought a CX-800 Peavey few years ago, and the fan was always activated, even when there wasn't any music played. It was so boring for home usage, that I sold it quickly and re-installed my homemade amplifiers (without any fan, but using large thermal dissipators).

I wouldn't like to do the same error with those QSC...

 

[JonSnell Electronic]

The CX-800 has a temperature sensor also, maybe it was faulty?
At low level, I don't expect it will be an issue. Why not aquire a Crown MZ range. Dead quiet as they are designed for studio work.

 

[Massilia]

The CX-800 has probably a thermal sensor too, but the fan is always activated, even at power-on. Surely the fan speed is increased when the output power is rising.

The one I bought was a brand-new one, don't think there was a problem with it.

Thank you for the Crown MZ info, I will look at it. The Crown Reference was very interesting despite its high price, but it is no more produced. If the MZ serie is similar, it could be the good choice!

Thanks again,

Regards

Bruno

 

[indianajo]

I put my CS800s PA amp under the couch, where the sound of the fan is damped out by polyurethane stuffing. I listen at the 1.5 Vpp level also in my music room.(peaks are much higher on orchestral music). The room has carpet on the floor and record shelves on the wall, so it is not a loud resonant space. There is also a wood console piano and wood organ case in the room along the walls. I use 10 gauge 3SO extra flexible industrial wire to make up the extra length to the speakers at the end of the parallelapiped room (shaped like Wein Philharmonia hall).