There was an amplifier on demo at the recent AXPONA which I found interesting and maybe so to forum members. A monoblock pair of amps from Infigo Audio was driving a pair of Alta Alec (edit: Adam) speakers. The amps looked wonderful and this system sounded great (really nice speakers!), but what most interested me was the amps are said to be pure Class A and rated at 250W into 4 ohms. The heatsinks were cool to the touch, though, so I asked the rep if they're modulating output voltage. I was told the rail voltage is held constant, which implies they could instead be doing some new twist on an active current source like the Aleph series amps. Except they're claiming a lot more power and producing way less heat than the Aleph amps.
Anybody have an idea what could be going on with this amp? (I also would have guessed maybe $10-20k for the pair, yet they're priced at $50k! The entire ultra high end has jumped the shark on top tier pricing. It was nice to see so many new companies putting out products, though. Many new names to me, quite a few of them coming from Europe.)
https://infigoaudio.com/page/method-3/
Anybody have an idea what could be going on with this amp? (I also would have guessed maybe $10-20k for the pair, yet they're priced at $50k! The entire ultra high end has jumped the shark on top tier pricing. It was nice to see so many new companies putting out products, though. Many new names to me, quite a few of them coming from Europe.)
https://infigoaudio.com/page/method-3/
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claim of pure class A + 250W@4R + cold sinks = pure BS!!
now, without false claims , one can judge amps by sound quality , and that would be only fair and proper, if only rep team didn't dealt BS
now, without false claims , one can judge amps by sound quality , and that would be only fair and proper, if only rep team didn't dealt BS
For what it's worth, according to Stereophile:
The Method 3 sliding bias class-A monoblock outputs 250W into 4ohms. Input is XLR only, weight 62lb, and bandwidth 10Hz–100kHz (within 0.3dB). Due to sliding bias, heat output is claimed to be less than expected. "We use hundreds of transistors," Infigo CEO/founder Hans Looman told Stereophile. "We also use relatively low current feedback to make the amps extremely fast." The amps only consume 35Wpc in idle. Note the wavy surface of the enclosure, which is designed to reduce fin resonance and allow placement near loudspeakers.
https://www.stereophile.com/content...nd-cabling-meets-alta-audios-adam-loudspeaker
The heat sinks aren't that big, and they don't look optimized for natural convection.
The Method 3 sliding bias class-A monoblock outputs 250W into 4ohms. Input is XLR only, weight 62lb, and bandwidth 10Hz–100kHz (within 0.3dB). Due to sliding bias, heat output is claimed to be less than expected. "We use hundreds of transistors," Infigo CEO/founder Hans Looman told Stereophile. "We also use relatively low current feedback to make the amps extremely fast." The amps only consume 35Wpc in idle. Note the wavy surface of the enclosure, which is designed to reduce fin resonance and allow placement near loudspeakers.
https://www.stereophile.com/content...nd-cabling-meets-alta-audios-adam-loudspeaker
The heat sinks aren't that big, and they don't look optimized for natural convection.
35 watts idle for 250 watts classA output is a mirracle of engineering, its actually producing more power that it consumes
A THRESHOLD power amp by inventor Nelson S. Pass is a reference to compare others with for all performance metrics to include the inter relationships of idle power, output power, heat sink size etc.
"Many people" think EVs are suddenly going to become plentiful beyond Tesla, but JB Straubel (former Tesla exec) had a tweet awhile back warning that manufacturers need to "do the math" to get their battery cell supply chains in order. I think it says a lot about why Tesla is so much better positioned, even as it is having a hard enough time to meet its own demand.
It is certainly possible to make very good amps with sliding bias. And this one here most probably IS one. But their web page is full of marketing BS. Calling it pure class A does definitely classify for the BS department.
Regards
Charles
Regards
Charles
well, one really doesn't need sliding bias per se..... "all" you need is just to avoid xover distortion, no part stopping conduction
so, if one achieve that, whatever steady current is, BS Department can call it "Full Class A and Personal Flux Capacitor and WhatNot"
so, if one achieve that, whatever steady current is, BS Department can call it "Full Class A and Personal Flux Capacitor and WhatNot"
Broskie has written repeatedly about sliding bias. History and practice.
https://www.tubecad.com/2007/12/blog0129.htm
Like many clever ideas, the devil is in the details.