Solid State Power Amp Reviews

Yamaha MX-D1 digital power amplifier Specifications

Sidebar 1: Specifications

Description: Solid-state stereo power amplifier with class-D "digital" output stage operating at 352.8kHz. Maximum output power: 500Wpc into 4 and 8 ohms (24dBW, 27dBW, respectively) at 0.1% THD. Frequency response: 1Hz–100kHz, ±3dB; 20Hz–20kHz, ±0.5dB. THD at 10W/1kHz: <0.003%. Input sensitivity: 1.3V. Input impedance: 25k ohms. Damping factor: 200 (equivalent to an output impedance of 0.04 ohms), no frequency specified. Channel separation: 100dB. Dynamic range: 120dB or greater (IHF-A, low-pass filter at 20kHz). Standby power consumption: <0.1W.
Dimensions: 17 1/8 "(439mm) W by 2 7/8" (78mm) H by 17 3/16" (440mm) D. Weight: 23 lbs (10.4kg).
Serial number of unit reviewed: E010173.
Price: $4999.95. Approximate number of dealers: not disclosed.
Manufacturer: Yamaha Corporation, PO Box 1, Hamamatsu, Japan. US: Yamaha Electronics Corp. USA, 6600 Orangethorpe Avenue, Buena Park, CA 90620. Tel: (714) 228-3343. Web: www.yamaha.com/yec/index.htm.

COMPANY INFO
Yamaha
6600 Orangethorpe Avenue
Buena Park, CA 90620
(714) 228-3343
www.yamaha.com/yec/index.htm
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COMMENTS
georgehifi's picture
Submitted by georgehifi on October 29, 2018 - 11:20pm

"so to examine the MX-D1's performance at low signal levels, I used an active sixth-order low-pass filter with a 20kHz bandwidth and a floating input."

Wow, with this almost brick wall filter territory at 20khz on it's output and you can still see the switching noise embedded in the square wave. https://www.electronics-tutorials.ws/filter/fil57.gif
Would have been eye popping to see it au naturel, an unrecognizable square wave most likely

"so I caution readers (and Yamaha) not to take the specific graphs as representing anything more than broad-brush pictures of the amplifier's behavior."

Pretty useless having these graph shots if they don't represent what coming out of the output of these Class-D's for readers to see what being fed to their speakers.
There never used to be a problem measuring with the AP gear showing the results without filter when Class-D was first being measured, like with the Anthem M1 Class-D
https://www.stereophile.com/images/1212AM1fig02.jpg

Cheers George

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