January 2015

World Premiere!
Parasound Zdac v.2 DAC And Headphone Amplifier
Another audiophile bargain from this San Francisco high fidelity audio company.
Review By Anthony Nicosia

 By now audiophiles the world over have heard of Parasound, a company specializing in high end audio, home theater and custom installation gear, all at affordable pricing. A privately held company it has been led by its President Richard Schram since its founding in 1981. Having owned their products in the past and currently in possession of their A21 power amplifier makes me no stranger to the company. That and the fact of having written a review about their then new Parasound JC3 Phono Stage in the April 2011 issue of Enjoy the Music.com makes me quite familiar with the brand. The Zdac v.2 is a replacement for the original Zdac. The differences between the newest version and the original being the addition of an analog volume control for use without the need for a preamplifier, a new headphone amplifier of increased gain, dual headphone output jacks and Lightning Jack Apple equipped IOS devices. These devices now allow you to send digital audio signals directly to its USB port via an optional Apple Lighting to USB Adapter. The Zdac v.2 also has improved system integration with 12-volt triggers and additional preamplifier features. You get all this while Parasound has only increased the price of the original Zdac from $475 to $549, which is only $74 more.

A Detailed Look At The Zdac v.2
Looking directly at the front faceplate from left to right you will first see a power and then an input button. The input button when pressed three times switches from the optical coaxial or USB input connections. To the right of the display are two gold plated headphone outputs, one for 1/8" the other 1/4" connectors. Use them individually, depending on which size is needed, or both can be used when you want two people to listen, each with their own headphones (then an adaptor might be necessary if both headphones have the same size input jacks). Actually that is kind of a romantic notion for couples into late night listening sessions, not wanting to wake children, pets or others within the home. Of course the volume would have to be set at a level both would be able to tolerate as one volume control manages both sets of headphone output jacks and each cannot be set at different sound levels. That is of course a very small price to pay for the luxury of dual listening.  With its10 Ohms output impedance and high gain the Zdac v.2 can drive headphones with impedances up to 600 Ohms. In the middle is the already mentioned digital input display with labels of OPT (obviously for TosLink optical),  COAX (S/PDIF) or USB. Finally on the far right of the front panel are two volume knobs, the first controls both headphone outputs with the other being for the sound level of loudspeakers if and when the Zdac v.2 subs as a preamplifier or is put in variable mode (more on that later).

On the back, left to right there are one set of balanced outputs for XLR cables, another for unbalanced RCA cables, it is always a plus to be given a choice of both. There is a volume control lockout switch labeled "Fixed" and "Variable". When switched to "Fixed" the front panel Main Volume control is disabled with the Zdac v.2 set at a "Fixed" maximum output. Use this when using a preamplifier, integrated amplifier or receiver to control volume levels for your audio system. It may also be used if your source components have their own volume controls. When switched to "Variable" the front panel Main Volume control is now engaged. Once set, their output levels are now controlled by the position of the Zdac v.2's Main Volume control knob. This setting should be used if your Zdac v.2 will be connected directly to your power amplifier. Consult the owner's manual for complete details. Of course, we also have three digital inputs for optical, coaxial and USB connections. With the USB input one may play music from a PC, MAC or Linux. You will find that Parasound has included a USB cable with the Zdac v.2. You might though also want to purchase The Apple "Lightning to USB Camera Adapter" which would then allow for a direct digital audio connection between your Zdac v.2 and Lighting equipped Apple product (phone, tablet, iPod). This adaptor can be purchased separately through your Apple store. From there all one need to do is plug the "Lightning to USB Camera Adapter" into your Apple product, and then using the standard USB cable included from Parasound, connect the adapter to the USB input of your Zdac v.2. Select the USB input on the Zdac v.2 and start playing music from your Apple device. The Zdac v.2 also comes with a factory supplied trigger output cable so one may now join it with other gear eliminating the need to turn each on or off separately. One last thing of note is the IEC outlet located on the rear. Here you may use the factory supplied cable or something of an aftermarket variety if you prefer to experiment. For this review the factory cable sufficed.

Now turn over the Zdac v.2 and look at its underside. Here you will see an AC voltage selector switch that can be set for either 115V or 230V, whichever is appropriate for your particular area of use. Damage caused by connection to the incorrect AC voltage will not be covered under the company warranty so please check this carefully and set it appropriately.

Inside there is a larger than expected internal toroidal power transformer. This, rather than a wall-wart, connector from machine to wall outlet and thus provides greater power for those peak current demands during difficult musical passages and works well at reproducing lower bass frequencies. Both optical and coaxial inputs will support 24-bit/192kHz sampling frequencies, while the USB connection is limited to 96kHz. All three inputs feature jitter reduction and are re-clocked and up-sampled to 422kHz/24-bit with asynchronous sample rate conversion for USB, optical and coaxial inputs alike. USB Streaming Controller is a Texas Instruments TAS 1020B. Being what I would consider half-sized at 8.5" wide by 10" deep and 2" high it took up only a small spot on a shelf inside my audio cabinet. Its size suited me just fine as it left room for some audio odds and ends within my racks limited real estate. Later when moved into my home computer system and sitting atop a desk it again took up a very modest amount of space allowing it to fit in rather easily. Making a move from one room to another was aided by the fact that the Zdac v.2 weighed only a modest five pounds.

A Variety Of Listening Pleasures
From time to time my Samsung HD841 DVD/CD player finds itself in my main audio system. Each time this happens it brings back memories as to why it has endeared itself to me over the years. One afternoon awhile back, C.C. Poon of Monarchy Audio and myself were enjoying music over at his companies listening room in South San Francisco when he showed me this overachieving CD player. Suggesting then that at its list price of only $250 it was quite the audio bargain I purchased two of them when they went on sale for $99 each. Listening to Mary Chapin Carpenter's Hometown Girl [Columbia CK 40758] with the Zdac v.2 attached to the HD841 via an Anti-Cable digital cable and two Audience e interconnects (both modestly priced cables) going straight through to my preamplifier, was an enjoyable experience indeed. The Zdac v.2 definitely took the Samsung to another level as it fleshed out a bit more of everything that could be found on the CD. There was a sense of true ambience that was evident in all performances. Bass sounded more natural and focused without losing weight while there was a greater front to rear depth presentation to give the soundscape a better sense of three-dimensionality. To test the Zdac v.2 a bit further out came my copy of Janis Ian's Breaking Silence [Morgan Creek 2959-20023-2], an excellent recording by the way. It should be noted that sometime during this listening session, I literally laughed out loud. Not at the Zdac v.2 but marveling at how great it truly was in combination with an inexpensive CD player. On "Guess you had to be there" bass response was very impressive indeed. Its accurate bass definition brought joy to my Magnepan 3.6's with their two optional DW-M bass panels. Not a bass machine alone, the Zdac v.2 was also quite capable of bringing detail to the upper sonic frequencies and adding a sense of air that surrounded vocals.

Pulling out a Cary CD500 (on loan from Blue Moon Audio in Pacifica) to substitute for the Samsung brought with it some trepidation on my part. After all the Cary sold for a bit over three thousand dollars when last available and has received many rave reviews since its introduction and here I was substituting a $549 product for this players already fine internal DAC. But this hobby of ours is all about experimenting and that is what some of the fun is about. Nothing else was changed, same cables, same setup. Being familiar with Parasound products it kind of was and kind of was not a surprise to find the Zdac v.2 performing in a spectacular way when paired with the CD500. Things did change slightly of course, with the Zdac v.2 bringing in a little bit more detail and giving up a slight bit of an analog laid back quality the CD500 is known to possess. We are talking small differences here and it must be said this matchup was simply wonderful. Which you would prefer is a matter of personal choice of course. On Diana Krall's The Look of Love (Verve 314 549 846-2) "I Remember You" the space surrounding vocals was quite breathtaking. It made this song the type you would love to sit and listen to with your significant other over a glass of good Napa Cabernet, Pinot Noir or even Chardonnay. Not the cheaper varieties mind you but rather something of the highest quality to match this beautiful sonic experience.

One particularly nice quality about the Zdac v.2 was that it never overpowered you with a too forward presentation; the type which threw the music straight at you. Rather, the performances stayed within an appropriate soundstage before you while exhibiting good front and back layering of the images of individual performers. Moving onto something with a little more complexity in slipped the Grateful Dead American Beauty CD [Rhino R2 74397]. On the opening track "Box of Rain" the Zdac v.2 made sure there was no doubt as to the location of individuals and instruments with each one clearly standing out with their own separate distinct onstage presence. Again, the sharpness of the attack transients was ear catching and well received by me. This combination of DAC and transport was so good that my wife came over during a TV commercial to ask me some questions. When asked if she liked what she had heard her response was a very affirmative yes. The Zdac v.2 gets a big thumb up here as she is usually mute on the numerous comings and goings of my various audio gears. If you value detail, this is one great DAC that should give you many hours of pleasure. Do not be surprised if it takes your listening sessions deep into the night and perhaps the early morning as you lose yourself within its magical spell.

Checking it out as a DAC/preamplifier a pair of RCA cables ran it straight into my Parasound A21 power amplifier, bypassing my systems own preamplifier. Doing this of course required me to reach around and flip the switch to variable so that volume was now controlled by the Zdac v.2's main volume knob. If you try this please be sure that the main volume control knob on the Zdac v.2 is set to its lowest point and only then when music is playing bring it up slowly to a comfortable level. Nobody would want to permanently damage their ears or equipment with a silly mistake like this. Actually the Zdac v.2 in this instance could have been set to "fixed" thus setting its output level to maximum, as the Parasound A21 power amplifier has gain controls for both left and right channels on its back panel where the volume could then be controlled. If you do this once again be careful and start the settings at the lowest point on your amplifiers gain control(s), then turn it up slowly until a comfortable sound level can be reached. My personal pleasure is to use my own preamplifier with its remote control so that if something gets too loud quickly it can be easily controlled from my listening position, but that is me. To compare my own $5000 preamplifier with the $549 Zdac v.2 would not be fair. If you run this as a DAC/preamplifier it would be my assumption you are putting it into a system to match its price point. Though it was surprising how well it did sound run this way. My guess is you could put it into a very decent audio system and not be disappointed. In fact after the initial direct comparison with my own much more expensive preamplifier it was easy to sit back and enjoy all it had to offer. As you can probably see by now this review was beginning to show what a great value and versatile component the Zdac v.2 is. Using it as a DAC/preamplifier might surprise you, as it did me, while maybe saving you some extra expense as well.

It was now time to bring out my Sennheiser HD497 headphones and check out the Zdac v.2's headphone amplifier. Those who enjoy headphones know that while allowing for late night listening without disturbing others it also takes the room acoustics out of the equation. With headphones music is piped directly into your ears and room construction, placement of furniture, the shape of one's room, well they no longer matter to the sonic experience. Not only that but if this is your only means of listening then the cost and placement of loudspeakers will no longer be a consideration. For these reasons it is good to have a quality headphone amplifier in your system and the Zdac v.2 brings us that. If you are used to a loudspeaker based system (as most probably are) you need do no more than plug in your headphones to either of the two headphone jacks on the front panel. Once done your loudspeakers will cease playing music and your headphones will now take over. Volume for the headphones will now be controlled by the Headphone Volume knob on the front panel of the Zdac v.2.

Take heed from the following warning found within the Parasound Zdac v.2 owner's manual:
Note: Headphones can create dangerously high sound pressures levels without the audible distortion you would hear from loudspeakers at comparable volume levels.... To protect your hearing please do not listen at high volumes for an extended time.

My Sennheiser's are not particularly hard to drive and so the Zdac v.2's high current headphone amplifier drove them with ease. Stereo imaging was quite excellent as was once again bass response. If you are using a receiver with a built in headphone amplifier this just might be your ticket to a big upgrade for a headphone listening experience. I quite happily sat down and enjoyed my Sennheiser HD497's in combination with the Zdac v.2's headphone amplifier as CD after CD spun on my player. Once again a detail magician, the Zdac v.2 rendered my CD listening experience pleasurable indeed. Never did it exhibit shrillness in the treble region but remained smooth and natural. This was definitely a quality headphone amplifier performing way beyond its price point.

Upgrading the music found on your portable devices for playback through your home stereo is a good idea. Here the Zdac v.2 gives you the ability to bypass a portable units cheaper internal DAC and to replace it with the Zdac v.2. While I did not try it that way, the Zdac v.2 was however hooked up to my home desktop computer, one that my older son and I had bought piece by piece after which we assembled it ourselves. He being a software engineer partitioning the hard drive and setting up all the software was a snap. My computer loudspeakers are a pair of powered M-Audio AV-40's. RCA Audience e interconnects connected the AV-40 to the Zdac v.2 via its outputs while the Zdac v.2 connected to my computer using the factory supplied USB cable. This was all really quite simply and it was up and running within minutes. You can see the owner's manual for instructions on how to set the Zdac v.2 as the default audio device. Being that the Zdac v.2 volume controls operate purely in the analog domain it should not adversely affect the music's resolution coming from your computer. Because of this Parasound recommends leaving the computers volume set at 100% and to control listening levels with the Zdac v.2 or any accompanying audio system. When listening this way there was a much improved three-dimensional quality to the music and digital harshness was held in check. Once again the sound was noticeably easier on the ears and allowed me to listen for hours on end without that dreaded listener fatigue that often accompanies gear of much lower quality. The M-Audio loudspeakers sounded better now than they ever had, to a degree that when playing B.B. King's "Everybody‘s Had the Blues" my whole body got into the rhythm, as it should. Mid bass response was no slouch either as there was now appropriate heft in that region as well, overall a very balanced presentation.

Conclusion
To sum this all up quite simply and quickly, the Zdac v.2 is a versatile product capable of performing a multitude of tasks. It never failed to perform admirably, not only within its modest price point but way beyond. You may use it as a stand-alone DAC (digital analog convertor) or DAC/preamplifier combination. You might even want to use it to play music from a mobile device through your home audio system or to be attached to a computer of the portable or desktop variety. You will probably feel like using it in a number of different ways as this new product did a great job of representing itself wherever it was placed and, at five pounds, was easy to pick up and move around. Even if you do not want to use the Zdac v.2 as a DAC because you like your digital player the way it is, consider using it just for its headphone amplifier and computer capabilities. You might even consider using the Zdac v.2 as a preamplifier for moderately priced audio systems looking to simplify and keep costs down. Given its pricing structure, versatility and quality surely most lovers of music will find a way to place the Zdac v.2 into their systems somewhere and come away smiling. At $549, this product "sings" and is another example of what the good folks at Parasound are churning out in the way of quality products with down to earth pricing. Be careful though and do not let that modest price tag fool you into thinking it is not all it should be, as it is that and more. So if you want to dance, check out the new Zdac v.2 from Parasound.

The Listening Environment
The review room is eighteen feet eight inches long by thirteen feet wide with loudspeakers and equipment kept on the short wall. The cathedral ceiling starts at eight feet on the short wall slopping upwards to reach a height of thirteen feet in the middle than returning to eight feet at the opposite end. The hardwood floor is partially covered by a nine by six foot oriental rug lying down the long ways facing toward the loudspeakers, placed dead center between but not under the listener or the audio rack. The room has no doors but there are two openings. One opening is in front of the right loudspeaker on the long wall giving access to the hallway the other behind the listening position to a formal dining area. There are three large floor-standing GIF Tri-trap acoustical panels two standing atop each other in the left corner and one in the right of the short wall in front of the listener behind the loudspeakers. There are also two acoustic panels from Acoustic Revive (AR) located on the wall directly behind each loudspeaker. A third AR panel is placed flat against the right side wall near that walls loudspeaker. The fourth and final AR panel is located behind the listener and to its left blocking a partial portion of the opening to the dining room located behind. Numerous Auralex Studio foam squares are placed along walls and high up in each of the four corners of the room. All the audio equipment is located in a Synergy Twin S30 Salamander audio rack placed about a foot away from and in the middle of the short wall opposite the listening position.

Review Equipment
Magnepan 3.6R Loudspeakers placed on special custom made three wooden layer platforms
Two Magnepan DWM Bass Panels
Aesthetix Saturn Calypso Line Stage Tube/Hybrid Preamplifier
Parasound A21 Power Amplifier
Samsung HD-841 CD Player
Cary Audio CD500 CD Player
Audience aR2p-TO Power Conditioner
Acoustic Revive RPT-4 Ultimate Power Supply Box
Cherry Synergy Twin S30 Salamander audio rack

Specifications
Type: Solid-state digital to analog converter, preamplifier and headphone amplifier
Supports Incoming Digital Word Lengths: 16 bit - 24 bit 
Supports Incoming Digital Sampling Frequencies:
  Opt & Coax
       8 kHz, 11.025 kHz, 16 kHz, 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz. 
  USB
       44.1 kHz, 48 kHz, 88.2 kHz and 96 kHz 
Upsampling Frequency:  422 kHz/ 24 bit (all inputs)
USB Streaming Controller: Texas Instruments TAS1020B 
Sample Rate Converter: Analog Devices AD1895
D to A Converter: Analog Devices AD1853
Headphone Amplifier: Texas Instruments TPA6120
Frequency Response: 20 Hz to 20 kHz ±0.2 dB
Channel Balance: < 0.05 dB, 20 Hz - 20 kHz
Channel Separation: > 95 dB, 20 Hz - 20 kHz
Signal to Noise Ratio: 110 dB, A-weighted
THD + Noise: < 0.015 % 
Audio Output Level, RMS (maximum): 
  Unbalanced Variable: 2.4 V 
  Balanced Variable: 4.8 V 
  Unbalanced Fixed: 2.2 V 
  Balanced Fixed: 4.4 V
Output Impedance: 
  Line Out: 160 Ohms, unbalanced or balanced 
  Headphone Out: 10 Ohms
Dimensions:  8.5" x 10"  x 2" (WxDxH)
Weight: 5 lbs.
Colors: Black or Silver
Price: $549

Company Information
Parasound Products, Inc. 
2250 McKinnon Avenue
San Francisco, CA 94124

Voice: (415) 397-7100
Fax: (415) 397-0144
E-mail: sales@parasound.com
Website: www.Parasound.com