2. amps-preamps
  3. 175552-145771

Paul Klipsch was right - What the world needs is a good 5 watt amplifier

For those who are questioning whether a low power high quality amp would be able to properly drive any speakers I've recorded a short video demonstrating very high SPL level from a speakers with average sensitivity. The video is of very low audio and video quality as its recorded from my smartphone. However, the microphone used for measuring the sound pressure is MiniDSP UMIK-1 and the software used is REW (Room EQ Wizard). During the tests the amplifier didn't show any hint of stress of distortion

The speakers used in this video are Sonus Faber Olympica II and the integrated amplifier is Pass Labs INT-25. According to some third party reviews the Olympica's are thought load for the partnering amplifier as their sensitivity is averagely rated (88db) and the impedance curve drops down to 3 ohms in the bass region with a estimated EPDR (the point where the impedance curve is intersecting with the phase angle) of 1.6 ohms. The pass labs is rated at 25wpc @ 8omh and is said to be stable down to 1 ohm doubling its power at 4 and 2 ohms. According to the manual it can deliver 200wpc @ 1ohm before the protection circuit is activated. 

So, the point of the video is to show that the Pass with its poorly rated power (25wpc) can drive even demanding speakers to insanely loud levels without any sound degradation. 

  

 

celestial__sound
atmasphere's avatar
atmasphere
11,834 posts
 

I cant tell you how many components I bought in the last two "Covid Years" that had great reviews/measurements by "Audio Science Reviews" that I had to return because they were unlistenable.

IMO too little attention is paid to distortion spectra when amps are measured; IME its one of the more important things to study in an amp. The real problem here isn't the measurements, its what is defined as 'good'.

divertiti
225 posts
 

@celestial__sound 

I've great appreciation for topping devices and with great respect I think the PA5 wouldn't be able to drive those speakers above 80dbs before it will start clipping. Don't rely on laboratory measurements as the music is much more complex and dynamic and it is not 1 KHz sine wave

Measurements don't tell you how a piece of gear is going to sound, no matter what brand, especially not measurements from REW. The music playback in the video didn't sound too great, even considering it's compressed Youtube footage.

celestial__sound OP
102 posts
 

The music playback in the video didn’t sound too great, even considering it’s compressed Youtube footage

@divertiti The video is recorded with my 70$ smartphone (huawei). Don’t you think Wilson Chronosonic driven by D’Agoustino Monoblocks will sound the same on my phone? Don’t you?

Please don’t waste our time with comments like this ... PLEASE

mrdecibel
3,063 posts
 

I recently sold locally a Pass ACA amp I had purchased 2nd hand. With my listening habits being what they are, it did not adequately power my Lascalas. 

divertiti
225 posts
 

@celestial__sound 

The video is recorded with my 70$ smartphone (huawei). Don’t you think Wilson Chronosonic driven by D’Agoustino Monoblocks will sound the same on my phone? Don’t you?

Please don’t waste our time with comments like this ... PLEASE

You are so close to self awareness it's actually painful. You posted a video measuring an amplifier using REW and an SPL read out making claims about distortion and sound quality, on a $70 cell phone non-the-less. "waste our time" is exactly the right phrase to describe this thread.

More to discover