John E. Johnson, Jr.

NAD M51 Direct Digital DAC

John E. Johnson, Jr.

 

Most audio component manufacturers have a DAC in their product lineup, and NAD is no exception. However, the NAD M51 is unusual in that it takes the incoming digital PCM bitstream and converts it directly to a PWM bitstream, which is then fed directly to the output. The idea has been around for about a decade, but the technology for implementing it was not fast enough in those early days. Now, with modern technology and techniques, NAD has produced what they call a "Direct Digital DAC", where the digital signal does not go through digital to analog conversion in the normal sense, but converted to PWM at 844 kHz sampling, with 35 bit word length. As you will see with the bench tests, the results are quite amazing, and the price is very affordable.

DACs

HiFiMan HE-500 Over-the-Ear Planar Magnetic Headphones and EF5 Headphone Amplifier

John E. Johnson, Jr.

HiFiMan is a relative newcomer (2006) to the audio product scene. Their specialty is headphones (including over-the-ear and earbuds) and headphone amplifiers. We have reviewed several of their headphones, with positive and enthusiastic findings. The HE-500, reviewed here, are over-the-ear headphones, meaning that they completely enclose the ears. This model also uses planar magnetic drivers, which unlike cone drivers, are flat, very thin plastic membranes, on which is attached a thin conductor. The membrane is near permanent magnets, and when the signal flows through the conductor, the opposing electromagnetic field on the conductive membrane is pushed away from or attracted to the permanent magnets, producing the sound.

Headphone and Earphone Reviews

D-Wings Cable Management

John E. Johnson, Jr.

All of us have had to deal with cable management in our audio and home theater systems. What we usually end up with is a tangle of wires that look like a mess. There are a number of cable management systems out there, but they most often involve tubes through which you pass the cables. D-Wings, marketed by UT-Wire, represent a completely different, and much easier to use, cable management product.

Audio Accessories Misc

Integrating High-End Two-Channel Audio into Home Theater without Compromise

John E. Johnson, Jr.

For those of us who enjoy two-channel (stereo) audio using a high-end system, but also like our home theater with surround sound, how to integrate the two setups without compromising the stereo high-end system has been a conundrum. In this article, I will show you how to have both systems interconnected, but not compromise the sound when you want to listen to your stereo CDs, or SACD in stereo.

Editor's DeskEditorial

NAD M3 Integrated Stereo Amplifier

John E. Johnson, Jr.

If you look at the specs of most stereo integrated amplifiers, the rated RMS power output is between 60 watts and 120 watts per channel. This is lower than the power output of outboard power amplifiers, which typically are about 125 watts to 300 watts per channel. Monoblocks go all the way up to 2,000 watts output. One of the main reasons for this is that in an integrated power amplifier, the preamplifier circuit is situated very close to the power amplifier. Keeping the high voltage, high current power amplifier signal from inducting noise into the preamplifier circuit is difficult. NAD apparently has solved this problem with the introduction of their M3 Integrated Amplifier, which has a rated output of 180 watts per channel, at 0.004% THD+N, and clipping (1% THD+N) at 220 watts.

Integrated Amplifiers

Velodyne vPulse In-Ear Headphones (Earbuds)

John E. Johnson, Jr.

With the prevalence of portable music players to the point that you must be from Mars if you don't own one, there is a huge aftermarket for high quality earphones (headphones is the category, with over-the-ear headphones, on-ear-headphones, in-ear headphones, in-ear-earphones, and in-ear earbuds being the specific type of headphone one is referring to). Velodyne, renown manufacturer of subwoofers, not to be left out of this trend, has released a set of in-ear headphones called the vPulse....and best of all, they sound like Velodyne all the way . . . a.k.a. very, very good.

Headphone and Earphone Reviews

Anthem P2 Two-Channel Power Amplifier

John E. Johnson, Jr.

Anthem's statement multi-channel power amplifiers are called the P series. They come in two versions, a five-channel (P5) and a two-channel (P2). My home theater test lab has a 200 watt x 5 amplifier which works great for the majority of applications, but it is driving electrostatic speakers (ESLs), and for a handful of Blu-ray movies, the amplifier will go into protect mode when at high volume, because ESLs typically have a very low impedance (1 ohm) in the high frequency range.

Power Amplifiers

Rein Audio X-DAC with USB Input

John E. Johnson, Jr.

USB DACs are hot items now because you can play music from your computer through them and into a set of headphones or to your main hi-fi rig. Some of these DACs only have a USB input, (no S/PDIF inputs) because their main purpose is for use with a computer. Of course, all computers come with audio ciruitry on the motherboard, and if you have a sound card installed in one of the PC card slots, it may very well have an S/PDIF output. However, their quality is often questionable due to the typically low cost of the sound card. Rein Audio, a German manufacturer, makes the X-DAC, which is a 24/192 DAC with both coaxial and Toslink optical S/PDIF inputs, but also, it has a USB input (24/96) to be used with your computer, giving you better sound quality than you would get from your computer's audio circuit.

DACs

Classe CP-800 Stereo Preamplifier

John E. Johnson, Jr.

Classé's new CP-800 is a high performance ("High-End") stereo preamplifier, but it is not just yet another preamp with minor changes from previous models. This one has the option of switching in some DSP that adds several EQ bands and dedicated stereo subwoofer outputs. If you don't use the DSP, it's not in the signal path, and you can still call yourself a "purist" audiophile. Have no doubts; this is a very unique product, and the performance is stellar.

Preamplifiers

Pass Labs X1000.5 Monoblock Power Amplifier

John E. Johnson, Jr.

We have reviewed several Pass Labs products in the past, and I finally decided to get a pair of what they call "Room Heaters", i.e., the X1000.5. These monoblock power amplifiers are rated at 1,000 watts rms into 8 ohms. They are similar in physical design to the XA200.5, but the XA200.5's are biased into Pure Class A, while the X1000.5's are biased about 80 watts into Class A, with the rest as AB.

Power Amplifiers

Home Theater Movie Renter’s Guide – February, 2012

The SECRETS Movie Review Team

To Kill a Mockingbird (Blu-ray), Dream House (Blu-ray), Dead Poets Society (Blu-ray), Manhattan (Blu-ray), Good Morning Vietnam (Blu-ray), Shakespeare in Love (Blu-ray), The Double (Blu-ray), Drive (Blu-ray), Rebecca (Blu-ray), Spellbound (Blu-ray), Lady and the Tramp (Blu-ray), Texas Killing Fields (Blu-ray), I Don't Know How She Does It (DVD), Tower Heist (Blu-ray)

Movie Reviews

Home Theater Movie Renter’s Guide – January, 2012

The SECRETS Movie Review Team

The Hangover - Part II (Blu-ray), Dolphin Tale (Blu-ray), Final Destination 5 (Blu-ray), 1911 Revolution (Blu-ray), The Rocketeer (Blu-ray), Contagion (Blu-ray), Colombiana (Blu-ray), Fright Night 3D (Blu-ray 3D), Killer Elite (Blu-ray), Rise of the Planet of the Apes (Blu-ray), The Scorpion King 3: Battle for Redemption (Blu-ray), Midnight in Paris (Blu-ray), Real Steel (Blu-ray), Blackthorn (Blu-ray)

Movie Reviews

Marc Audio Premium Line RCA Interconnects

John E. Johnson, Jr.

Marc Audio started its business of marketing quality audio cables in its on-line store only two years ago. They did not have all of their products available at the time of launch, so we reviewed what they had, as they became available. These included the Reference Line and the Signature Line. The Reference Line is their most expensive cable, but at $870/meter-pair for the RCA interconnects, they are not all that pricey compared to many other cables out there. The Signatures are their mid-priced cables ($549/meter-pair for RCA interconnects). Now, Marc Audio has introduced the Premium Line, which is their least expensive line of cables, at $158/meter-pair. Their construction quality - and more importantly - their performance, belie their very reasonable price, and I think they are one of the best values in cables out there.

Audio Cables