3 replies to this topic

[usa_satriani]

Hello,

I am not a classical crown user as I use my amps mostly in my appartement  

I have 2 D75A, one K2 and a MT1200.

The MT1200 is used to power the LFE's of my home-theater system.

The problem is that during the quite scenes, the fan makes a lot of noise.

I'd like to put a 120mm papst fan, but I know that the MT fan also provides some voltage.

So what can I do ?

Thanks, Greg.

[DGlass]

We did make a lower velocity fan blade for the MA/MT series that made less noise . It was however usually only recommended for nothing larger than a 1200 and for nothing lower than an 8-ohm per channel load. Basically the air flow is slowed down enough with this fan blade that the larger amps, or even the smaller ones with a lower impedance load, may not get enough air flow to stay out of thermal when being pushed. The lower velocity blades are still available from our parts department as part number C6594-3.

The MT fan is need for the amplifier as it is also used for the low voltage Power Supply. Disconnecting the fan would cause the amplifier to not work. As I see it your only choices, for using this amp without fan noise in a home theatre situation, may be to relocate the amp or try the lower velocity fan blades.

[usa_satriani]

Thanks for your reply and the info for the fan.

I know that the amp doesn't work when the fan is disconnected because I tried it This is how I noticed that the fan was used for power supply. But what I wanted to do is a trick, like a resistor so the amp "thinks" the fan is still there and then put a big silent fan.

Anyway don't worry, the warranty expired a long time ago

Maybe I should change the amp to another K2 or a DC300

[DGlass]

Thanks for your reply and the info for the fan.

I know that the amp doesn't work when the fan is disconnected because I tried it This is how I noticed that the fan was used for power supply. But what I wanted to do is a trick, like a resistor so the amp "thinks" the fan is still there and then put a big silent fan.

Anyway don't worry, the warranty expired a long time ago

Maybe I should change the amp to another K2 or a DC300

There is nothing you could do (other than a complete redesign of the amplifier's power supply ) as the winding of the fan motor (transmotor as we call them) is the tranformer for the Low voltage power supply.

Going to a K series might be a better choice.