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Specs for the bridged mono/one SMPS1200A400 or two SMPS600: 400/800/1200W @ 8/4/2 Ohm, safe to 1 Ohm but no rating. With one SMPS600: 400/800 @ 8/4 Ohm, safe to 2 Ohm but no rating.
Where do those specs come from? What, in your view, is the limiting factor/parameter for going down below 2 ohm?
Email from Bruno to me
So PS current and number of NC400 determines minimum impedance into which NC400 is safe and minimum impedance into which the amp delivers rated power. AFAIK this relationship is linear and unrelated to whether NC400 is single or bridged.
Thanks - I am curious, did Bruno actually use the word "safe"?I agree with the "minimum impedance into which the amp delivers rated power", as the amps become current-limited. But I am curious about the "safe" part. What does "unsafe" mean? Amp goes in to oscillation? Amp gets damaged?
Yes, IIRC Bruno used the word "safe."
It means you are, employing the late James Bongiorno's words to me, "tempting fate." It means to employ a load with less than the rated safe spec is "unsafe" and hence outside the intended use/application of the device. I presume all vital components have similar performance ceiling, meaning any number of immediate major component failures from one to most of the major components might fry. Conversely, if the many failure systems all work perfectly, you might replace only a fuse. That's where "tempting fate" comes in.
The point is, specs like minimum load impedance can be confirmed, and must be confirmed if there is any doubt, and to ignore or exceed the specs is "unsafe" and to be avoided.
I think we're going in circles, on the same page, etc.
Anything can fail. Current limit protection comes under the heading "anything."
The lower the load impedance the higher is current demand. If you believe current demand and load impedance are universally unrelated I strongly disagree.
When one clearly crosses the line (beyond gray area) re. minimum load impedance, and for whatever reason the amp's "current limit" protection simultaneously fails for any time period no matter how brief (they only must occur at the same time), what is the obvious or implied risk? Burn component and that acrid smell of money flying out one's wallet with which I'm all too familiar.
We're back to "tempting fate."
Roger, what you posted I have read is the case with stereo amp used as bridged mono. But IIRC Hypex principal Jan-Peter said it's not the case with bridged NC400, but that may apply only when bridged PS current is doubled vs. stereo. My 93 dB AudioKinesis Zephrin 46 speakers are unique in that each channel comprises two 16 Ohm separate loudspeaker loads: a "Main/On Axis" section and "Late Ceiling Splash" section. The two sections can wire parallel (8 Ohm) or series (32 Ohm). Bridged NC400 makes 100W @ 32 Ohm, so I'm anxious to audition it both ways. I shall also audition bridged NC400 powering the 16 Ohm "Main/On Axis" section, with my receiver powering the 16 Ohm LCS section.
But IIRC Hypex principal Jan-Peter said it's not the case with bridged NC400, but that may apply only when bridged PS current is doubled vs. stereo.
The only thing that solved fairly bad AC Mains hum in the bridged amp was to lift the chassis earth.
In view of the previous exchange in this thread, can you share with us Jan-Peters exact words?