Sansui au-919 & ventilation

[DB-7]

I would be interested to know with your fan experiment which direction do you have the airflow? Is the fan blowing into the amp or sucking the air out? Have you tried it both ways to see if there is any difference?

 

[penmarker]

As heat rises and the fan is on top of the vents, sucking it out would be the best way to enhance natural convection.

 

[StirFriedFrp]

Yes it sucks the air out. I didn’t try it the other way around.

I took some extra care to ensure that my thermometer is not IN the airstream itself. The fan stands on rubber edges which leaves no space between the fan and the amp.

 

[stereofanboy]

I have a turntable temporarily on top of my seldom used 919. I put hockey pucks under the turntable's feet and it seems to work fine.

Side note, it was years between the first time I read about using hockey pucks this way and the first time I saw a hockey puck in person. I didn't even know they were made of rubber.

 

[pjrengineer]

Great idea putting a fan on top of the 919. Mine gets quite hot in the summer in my garage setup. But it’s only 77 degrees today. I will measure it when it’s 93 and I can barely stand outside to see how hot it gets.

 

[Bright_Star]

The AU-919 sometimes poses as a grand piano

 

[jefferylhenr]

I see more heat coming off the heat sinks on the selector board than necessarily off the main heat sinks. I restuffed the power filters with new 10,000 uf 80 volt UCC’s and the heat and mainline draw went down noticeably

 

[NenzBenz]

For anyone who is interested: I bought a DHT22 temperature sensor, and taped it directly above the heatsinks of the AU-919. There is 4 cm free space above the amp:

View attachment 2746829

The sensor is connected to a raspberry pi. It measures the temperature every 5 minutes and writes the data to a Google Sheets file. These readings can then be put in a diagram. The following are two of such day readings. You can see exactly at what time I turn on or off the amp.

View attachment 2746831
View attachment 2746832

The temperature stabilizes at around 39 celsius. At this temperature the amp feels quite warm to the touch but definitely not too hot to touch.

The next experiment is to set some kind of warning threshold, if temperature exceeds 42 celsius or something.
Another experiment that I'd like to do is remove the 4 cm space and simply put the other machine on top (an MA7 on its feet). I am quite curious if there is a change in temperature to be seen in the readings.

How did you manage to power that fan?

 

[StirFriedFrp]

I am in Europe. I bought a universal power adapter with switchable voltage settings. 3,6 W, 300 mA. The fan runs fine on 12 volts. In addition I put a switch in between, so that I can turn it on and off.