Changing topic for a while, I was dissapointed to hear the BSS at first, not the audio output, but the noise that it's fans make. So I decided to look into disconnecting the fans, as others have apparently done. First, I looked inside. It seems that the brains of this BSS are an Altera Stratix 2 FPGA and two Analog Devices Sharc DSP chips.
The FPGA is from a family introduced over ten years ago, a 70nm process platform. But I guess it's maker must still regard it as a good chip, it seems to still be in production, and is available at Mouser for $460.00 Ouch.
The fans are four Sunon KDE0504pkv3s. I looked them up, and they are specced as some of the quietest 40mm fans available, at 18Dba each. So replacing them with something quieter probably wouldn't help. That's a lot of fans and It doesn't seem to me that the engineers would have put them there if they weren't needed.
I wanted to see where the heat was coming from inside the unit, and used the low tech method of putting my finger on all of the chips and cans. There are air flow dividers inside, the the left two fans cool the left side only, and the right side air is directed to the power supply and main board. The whole left side, where the input and output cards live, seems to be nice and cool. It doesn't make sense to me that those cards have two fans cooling them. So I disconnected those two fans right off the bat, and that works great, half the noise. My theory is that if you had ordered the unit with digital cards over there, you would probably still need those fans.
On the right side of the unit, the DSP chips were very warm to the touch, and the FPGA was hot, so hot that I couldn't leave my finger on top. Ouch again.
I decided not to just disable those two fans on that side. For some reason, these chips don't have heat sinks. Reverting to my old overclocking habits I decided to add some to those three chips. I cut an older Foxconn P3 CPU heatsink into four parts, with the bandsaw. Then I glued them in place on the FPGA and DSP chips. I used Arctic Alumina heat sink epoxy adhesive. It conducts heat well. And those heatsinks are there to stay.
I then disconnected one of the remaining two fans on the right side of the box.
There is a lot less noise with this single fan setup, it's hardly noticeable if you walk away from the rack. Now it's about the same noise level as the satellite DVR that lives in the same rack. I'm looking at adding a foam filter to the remaining fan to further silence it. And now you guys may be wondering if I'm OCD or something, and why can't I just leave anything alone. Well it was bugging me, and now it's not, so to me it was worth the time.
PS, For any fellow OCDs, to open the box you should have a Pozidrive PZ2 screwdriver available, and a 5/32 allen wrench.
(@#$% Pozidrive!)
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