The Black Hole......

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#3,244
Nice amplifier. I would expect less mains spuriae (1W measurement) and lower HF distortion.

520PHJC1Pfig03.jpg


520PHJC1Pfig07.jpg
 
#3,248
Right on PMA! I saw that too, and I reported it to Parasound, weeks ago. Upset somebody over in Asia I believe. I hope to look into it with a hum pickup (sniffer probe) myself when I get the chance. It is embarrassing. I never checked the distortion, etc without my 400 Hz filter in place so I overlooked it, until I saw what JA measured in the review. Next time I will be more careful.
 
#3,254
I have some say in the product, and I can be sometimes annoying to the people responsible who put it together. My very BEST products have been built by my personal team and me, like the Vendetta Research Phono and the CTC Blowtorch. I rarely build my own power amps any more, just not enough space. BUT I do the audio circuit design part still, and I do have finished samples sent to me for final approval. I have a JC-1+ on my test bench in the other room, for example, and I measured it months ago, before a similar unit went for review. It measures OK, for a medium feedback amp, optimized for under 25W operation, but not clipping till at least 450W into 8 ohm, or much more into lower Z loads.
 
#3,255
john curl said:
I have some say in the product, and I can be sometimes annoying to the people responsible who put it together. My very BEST products have been built by my personal team and me, like the Vendetta Research Phono and the CTC Blowtorch. I rarely build my own power amps any more, just not enough space. BUT I do the audio circuit design part still, and I do have finished samples sent to me for final approval. I have a JC-1+ on my test bench in the other room, for example, and I measured it months ago, before a similar unit went for review. It measures OK, for a medium feedback amp, optimized for under 25W operation, but not clipping till at least 450W into 8 ohm, or much more into lower Z loads.
Click to expand...

John,

Just a question, no hidden agenda:
Why so much available power, who needs a potential of 1KWatt + when the objective is to get a system that’s optimized system for under 25 Watt.
It is probably no coincidence that up to 25 Watt the Amp works in class A.
Is it just a commercial issue, big is beautiful, to justify the price that wouldn’t be possible with less power or do you realy see auditory benefits.
But when more available power would mean better sound, what would be the next step, 5kW, 10kW ?

Hans
 
#3,256
Specific figures in the power of the amplifier are associated with the sound pressure that acoustic systems create. The calculation also has a conception of the sensitivity of these speakers. There are such formulas. They show that in order to create a sound pressure that reproduces the piano at its peak, it is about 110dB, for conventional speakers with a sensitivity of 96dB / W / 1m, an amplifier power of 25W is sufficient. However, for speakers with a sensitivity of 86 dB / W / 1m, 300W is required from the amplifier.


For speakers with a sensitivity of 90 dB / W / 1 m, 1000 W of amplifier is required to create a sound pressure at a peak of 120 dB. This is a level of studio quality.


I repeat that all these three calculations are for a small room with an area of ​​20m2 and a ceiling height of 3m. Or at a distance of 1 m from the speakers, if they are in an open space.
And these powers are musical peaks, and not constant, like for example the noise of a take-off airplane, etc.


High-End Gold Note - калькулятор звукового давления в комнате, усилите
 
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#3,258
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