Just curious. Plus how much ventilation needed at top?
@dclark2171 - 8.75in high w/ feet. I mounted the BHK250 in a glass rack with 9.5in vertical spacing and it never got hotter than 115F measured w/ laser thermometer. Measurement taken at hottest spot - center of heat sink on sides. Distance of 0.75in above the BHK250. I then removed the feet and added IsoAcoustics Bordeaux pucks and the height went to 9.5in, then changed rack posts to 11.5in and temp still never went above 115F. That is 2in spacing above the BHK250.
Great info I really appreciate it. I was thinking of trying Stellar monos, now leaning toward BHK250 and looking at my rack cofiguration.
@dclark2171 - Either BHK250 or BHK300s, they both sound amazing! In the BHK250 rack setup, the BHK250 never got warmer than 115F. As you can see, I had Isoacoustic Bordeaux pucks under the BHK250 on the bottom shelf. If there was a heat issue, it would have also affected the P20 performance and it did not. The BHK250 top is about 10F to 15F cooler than the heat sink (sides); most of the heat is radiated through the heat sinks on the side (convection). You need to consider that when choosing a rack or setup; however, not a huge impact. The BHK250 rack configuration timeframe was 11 months (both 9.5in & 11.5in rack spacing) before moving to the BHK300s and never an issue with the BHK250. In addition, that amp is very powerful for a stereo amp. Going to BHK300s was a definite step up; however, not as big a step as you would think and my speakers are 86dB SPL efficient.
The VTI rack (company in CA) is glass that is 0.40in thick and can hold 220lbs per shelf (spec). Either P20 or BHK250 shelf never had an issue. The rack is completely configurable with different poles for different spacing (7.5in, 9.5in, 11.5in, and 13in). The company is very easy to work with (Linda). I have reconfigured the rack many times (5 to 6 shelves) as I built and modified the system. Six shelves in the BHK250 rack configuration and five shelves in the BHK300s rack configuration.
Hope this helps.
My rack w/ BHK250
My rack w/ BHK300s