Turned out to be quite true in my case. : )
Ok, I’m ready to pay shipping and take it off your hands 
Already gone. 
Too late, Jedi. But keep trying. I love a guy who is always on the lookout for a free deal 
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We’re on it, sir. Making good progress on the speakers now.
I’ve got BHK 250 Serial Number 009 that’s been running fine since it was first delifered. the only reason I had to send it back was because the terminals went wonky and had to be replaced (and a few components were upgraded to meet current production units) But it works fine. I still think th four e HiFi tuning Supreme rail fuses I put in improved sonics quite a bit, so much so that it didn’t seem worth going to the 300 monoblocks.
And the Steets 950 I bought back in 1984 actually still works, (hence my sig), so amps are the least of your worries. I still have my IVH, but the volume pot went south so i don’t use it any more.
The only real failure I had was in one of my speakers: The now nine-year-old Martin Logan Spire right channel would drop out intermittently. Very annoying. (Was it the amp? Speaker? Swapped left/right channel at the amp: problem stayed with the right speaker. OK, focus on speaker.) I washed the panels, switched the ESL panel from right to left (problem stayed with the right speaker base and woofer amp) and I finally discovered a loose terminal inside the right speaker base. Screwed it down and it’s been running fine ever since. But, yeah, the vibrations from the speaker loosed the wire after 6 or so years. who’d a thunk?
But I may have to get the AN2 (what’s the new designation?) when I retire. That would be fun . . . .
If my ears don’t degrade like my Dad’s . . . .
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I somehow had missed reading your post. Thanks for the feedback about your experience.
Pretty neat that in this thread there was only one (that I recall) case of serious failure of the BHK amps, despite the heavy scrutiny looking for failure evidence in this thread
@Paul If given the opportunity to keep the amps running at an ideal temperature, what is that temperature?
I am looking at a few installation options and one of them could be a temperature controlled cabinet.
Thanks in advance,
Vince
I’d try to not over think it. Even though a temp controlled cabinet sounds pretty damn awesome! Excessive heat is obviously what you want to avoid. It’ll be able to reach its comfortable operational temp within a pretty wide range. I’d say anything between 65-78F and you’re golden.
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@jamesh - Thanks! This is exactly what I needed to know.
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Hey Jamesh 65-75F is seems like an idle cold range but in full swing
it seems the BHK 250 would probably reach 90-100F any thoghts?
Best wishes
I was referring to the temp within V’s cabinet, not the amp itself. Yes, the amp will be much warmer than 65-78F.
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Thanks whiz kid…indeed the temo inside V’s cabinet would
tend to keep things cooled down nicely…as you said earlier…
“golden”
Best wishes
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As an experiment, I put a AC Infinity AIRCOM T8 directly on top of a BHK 250. I set the it to maintain 90F. Before I put it in place I ran my system pretty hard for several hours (which is always fun!) to get the amp warmed up. When I placed the AIRCOM on top of the 250 it read that the temp was 107F. It took ~2 hours while still running pretty hard (more fun!) and the temp came down to 92F which it then maintained steadily. I’ve since adjusted the AIRCOM to maintain 95F.
Which brings me to my next question. If I can maintain an optimal steady 250 operating temperature, what’s ideal? Is there any drawback to running it less then 110F? Is there any degradation in sound or lifespan if I run it cooler then the 250’s natural tendency?
Quick question based on my limited A / B understanding of amplifier topology.
Class A - On all the time at idle
Class B - On half the time at idle
A “Class A” amp should not get “hotter” with music playing since it’s always at 100%.
*Question
So, the difference in heat dissipation at idle vs. cranked up in a Class A/B amp will be dependent on how far “cranked up” gets you into the B side of the amp?
Or, putting it another way, a “hot” class A/B amp that does not get hotter when “cranked up” is actually a good thing (staying on the A side of the amp)?
Unless my understanding of thermals in Class A/B is wildly off the mark? Thanks
I’m not certain there is a known value here. My guess is there’s a fairly wide range for this. Unless someone were to run this experiment and try to narrow in what the best sounding temp is, I’m not certain there’s a known “ideal temp.”
Too cold? Sounds bad. Too hot? Potentially sounds bad and degrades longevity.
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Lifespan of electronics we’ve always tried to maintain steady temperature and (low) humidity. This is more important than any ideal temperature (although operating well in the middle of operating temp is the goal and there are industry standards for this stuff). There are some things, like oscillators, which operate “within specification” over a wide range of temperatures but are more accurate within specific regions of that range. Knowing the specific part number would let us find these graphs and we could then try to operate within this ideal. Although, I assume that would be more critical for DACs / other digital components than Class A/B amps which should settle once a stable temperature is achieved. But, I’m playing Internet EE here today
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i like my electronics to run cool, and will take reasonable steps to keep it that way.
i have never, ever, had a failure of any electronic device in my life that wasn’t obviously due to mechanical damage or some other external reason.
these two may be coincidental, modern electrickery is very reliable anyway (but see my thread elsewhere on running budget eu destined gear on uk’s slightly higher voltages).
I worked at an R&D lab at Hughes for many years. We kept it cold (65F) and low humidity, I can’t remember how low, but I don’t think my skin has ever been that dry since. We also never turned anything off.
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