A two-channel system can be surprisingly satisfying with the right equipment and setup.  Everything can be improved.  I was rather happy feeding a Marantz DVD into a Bryston B100 SST integrated with a separate CD player for redbook CDs.  But… it was a bit cluttered and annoying to have one extra box and remote.  I wanted to use my DVD player as a transport and free up my Linn player.  I stumbled upon the Pacific Valve Modified Lite Audio DAC AM.  It was suggested that it could equal the openness and soundstage of the Linn for a $499 list price and $340 sale price.  Could it be true?

Overview

Pacific Valve, based in IL, has made a small name for itself importing and modifying vacuum tube components for sale.  This particular model is sans tubes.  They take a Lite Audio DAC AM and modify the internals.  This oversampling DAC has a built in headphone amplifier and has a front panel selectable input for the three inputs; coax, Toslink, and AES EBU.  Front panel LEDs indicate the chosen input as well as the digital frequency.  I have only seen 44.1 and 48 yet it supposedly does 96 Khz as well.

The DAC AM modifications include replacing four Fairchild Op Amps with AD827s, three stock capacitors in the critical signal path to ELNA caps, and 6 Vishay RA resistors replace others in the critical path areas.  Having done a fair amount of DIY speaker crossovers, I have found that decent parts do make a difference and opted for the modified DAC AM.

Out of the box

The package arrived by a smiling UPS man who is amused at all the audio related parts coming to the house.  When I unpacked the box, I see that the real box is marked for 220V operation.  Excitement turns to frustration and resentment.  A quick email and phone call to Pacific Valve were in order. A relaxed southern gentleman contacted me within 15 minutes.  He took some information and assured me that the box was mis-marked and that it was 110V.  I appreciated the prompt response because I was now in business.

Setup

The stock power cord was discarded per the company's recommendation.  Given the budget high end flavor of this DAC, I used a trusty Volex 17604 shielded 14G 3 conductor cable.  Later comparisons found this to work very well with this DAC. The Volex was plugged it into a Furman PST-8 D power strip and the analog outputs were filled with Blue Jeans LC2 interconnects continuing the budget cable theme.

The DAC AM is small enough to be placed alongside a standard sized CD or DVD player on a 26” shelf.  It looked right at home on my 29” maple shelf next to a DVD player. The too-bright red LEDs detracted a bit from the appearance.  When I took it out of the box, I imagined it would be cheap and light with lots of plastic.  The build quality was actually quite nice.  It’s a solid unit with a metal chassis and a rather nice faceplate. The chassis did vibrate when I turn up the music.  I haven’t been able to tell if it affects the sound.  I applied 4 small Sorbothane pods to the feet which seem to have made little difference, if any.

 

How does it Sound?

When I first fired the DAC AM up, it was a tad on the bright side but not annoyingly bright.  The original application was to use it in my smaller system comprised of some Maggies, a budget sub, passive preamp, Forte Model 5, a Squeezebox and an old carousel CD changer.  It sounded so good I ended up putting into my main system. The first thing I noticed about the sound is that it actually embarrassed the Redbook section of my Linn Classik.  It has the same openness and soundstage but everything was cleaner and smoother.  An increase in dynamics was something that I had hoped for but was surprised to actually get.  I forgot how much fun a dynamic driving rhythm can be.  The bass was less obvious but noticeably stronger.  All of a sudden all the trinkets in the room were rattling to the bass even though there seemed to be less deep bass.  What had happened is that the deep bass had tightened up quite a bit.  It was tighter but with more slam.  I literally spent about 2 hours playing test tones and finding the rattling sources and “treating” them.  I didn’t mind.  This thing was sounding great.  It had not even been fully burned in yet but I knew I was not going to send it back.

After about 2 weeks of playtime, the sound had warmed up quite a bit.  I kept it on all the time and still do, mainly because it’s a pain to turn off without a remote control.  Note taken about the sound at that time still hold true.  The highs seem a bit rolled off but very well delineated.  Cymbals sound much more enjoyable, particularly the decay which seems just right.  The soundstage is quite wide and accurate but perhaps a bit further back than portrayed by the Linn, but then Miles Davis comes right to the forefront for his solos. No complaints there.

In addition, the Pacific Valve modded DAC has a sense of smoothness and palpability that I have only really heard through very expensive systems or Vinyl.  Yes, I did say vinyl. That immediately led to me feeding it some Led Zeppelin.  “Houses of the Holy” had that sense of openness and space combined with a lot more inner detail than I expected.  The guitars at the beginning of “Over the Hills and Far Away” were eye-opening.  Robert Plant’s voice showed some over modulation of the recording itself in some peaks in “The Ocean”.  The fact that it comes through is a function of the resolution of this DAC.

Diana Krall’s tunes usually sound a bit on the warm side via this DAC.  The inflections in her voice are magic.  She’s in the room singing just for me, right?  Her voice can sound smokier with this DAC than I remember and when I moved on to Dire Straits, the sound was outstanding.  In “Her Latest Trick” you can clearly hear Mark Knopfler take a breath between “And all I can do is hand it to you” and “and your latest trick”.  The song “Private Investigations” is an absolute imaging joy not to mention a big testament to the dynamic capability of this DAC.  I have been enjoying Miles Davis and Duke Ellington quite a bit through this.  “Kind of Blue” really just takes you away into the music.  The release I have was re-mastered on an all tube Presto machine and the added tube characteristics came through clearly.

                                                                                                                                                                                                                                                                                                                                                                                     

Although the CD section is quite nice, this thing really shines with higher resolution DVDs. A good example of this is the Beatles “Love” release.  The DVD section sounds absolutely amazing through this.  The CD section is impressive as well.  It’s lively, dynamic, and detailed.  The Beatles “1” sounds annoyingly bright in comparison.

A fair testament to this machine is that after I added it, I found music was being played in the home more often.  There was less TV and more music and conversation.  I came home one day to find my wife had a random mix of Rachmaninoff and Nirvana playing through it.  Whoa!  At least we know it’s suited to all types of music.

I mostly used a Marantz DV4300, an old Nakamichi MB-2s, a Panasonic DVD player, and a Samsung high definition tuner as digital sources to feed the DAC.  The Marantz was not as good as a transport but the real differences turned out to be in the cables.  The sound seemed to follow the cable more than the transport.  I started out with a decent budget coax from BlueJeans and a Mitsubishi Toslink POF cable   The Mitsubishi POF cable sounded dull and lifeless in comparison to the BlueJeans coax.  I spoke to the folks at Pacific Valve and they said that they try to use good quality coax with this unit as they don’t like to invest in expensive optical cables.  I found a glass optical cable and tried it out.  I then had a series of double blind shootouts with these cables.  The short version is that the BlueJeans coax and a Dayton GOC-3 from PartsExpress came out the clear winners with the number of folks preferring the Dayton cable beating the BlueJeans by a margin smaller than the margin of error.  There was a difference but folks could not agree on which was better.  In my opinion, the Dayton glass optical cable was a little smoother and warmer than the coax but with better sounding highs and imaging.  Others preferred the livelier BlueJeans coax but nobody felt real strongly about the difference between these too.  We all agreed that the POF cable was the loser of the bunch in this setup.  For reference, the two favorite cables were under $30 for a 3 foot cable.

Headphone Amp

I tried the headphone amplifier a couple of times.  It was as good as I remember but I am not a headphone expert so I let a few others try it out.  There were no complaints and basically thumbs up across the board.  I guess it is OK that the volume for the headphone amp is not remotely controlled as you’re tied to the DAC in that case anyway.

Comparisons

I compared this DAC to the stock DACs in every transport mentioned in this review so far.  There was really no contest.  The modified Lite Audio is in an entirely separate class.  That being said, I did a quick comparison to some more formidable foes.  Both the Rega Apollo and Bryston B100 SST’s DACs are a tick up from this DAC in sound quality.  They are both a bit less warm and more neutral and are a bit silkier in the critical midrange.  A good guess as to why is jitter.  The Rega has one clock vs. two asynchronous clocks in the case of using a separate DAC.  The Bryston DAC attacks jitter by buffering up and re-clocking the data.  I thought about purchasing each of these.  I chose the modified DAC AM over the Bryston merely for price.  I think about that each time I have to manually change the DAC AM’s input selector.  The Bryston DAC is remote controlled just like any other input on the B100.  I chose the DAC AM over the Rega for both price and the fact that I get to enjoy DVD movies in very well defined two channel with the DAC AM.

Visitor

Before the whole cable double blind test, a veteran audiophile friend of mine had stopped by to visit. After talking a while over Joshua Bell in the background, we ended up cranking the system up with some old releases we both knew well.  By the second song he’s obviously engaged with the music.  He’s sitting up in that “listening” position like the dog who’s listening for his master.  Eventually, he slowly turns his head to face me.  His eyes are big and wide a slightly bewildered expression.  He quietly says, “This sounds gooood”.  He then hones in on the ugly red LEDs of the DAC and goes over to investigate.  Next thing you know we have the Revel F30s in and we’re ripping through CDs like kids with new toys.  He ended up buying one of these DACs for himself online that very night!

When his DAC arrived he agreed with me about the initial brightness. Three weeks later he thanked me and said how much he loved it.  It’s a bit embarrassing writing such a positive review, but I really like this DAC.  That same friend stopped by last night and we both agreed on every positive.  I should note that he tried THREE transports and found clear differences.  The old Denon was just OK.  The old Sony was not very good.  He said it matches really well with his new Pioneer SACD player which he is really using for just redbook and DVD-A in two channel.  Note that he used the same power cord and coax.  I think it cost $7.  Not bad.

The Good

I found this unit to be fantastic at its $340 sale price.  I might even buy another to go with a squeezebox.  For a specific set of folks, this is an amazing machine and a great value.  If you have an older transport that you want to bring back to life, or juice up your Squeezebox with maximum Mojo, then this is the perfect solution for you.

                               

The Bad

Those who want to use their DVD players for both surround sound and CD will need to look elsewhere.  This can only decode PCM. Another bad thing is that there is no remote control.  This is rather bothersome for those who want to connect everything through the DAC.  One must get up and physically switch the input.  This is a black mark for a unit that performs so well.

The Ugly

My wife hates the brightness of the red LEDs on the front and the fact that they’re spread out at an angle. At a distance, it makes it difficult to discern which input is selected.

 

The Pacific Valve Modified DAC AM is recommended for anyone who seeks an improvement in audio quality over a basic, entry level two-channel stand alone CD or DVD player if they can get by without the convenience of a remote control function. At its price, it represents a very good value. Our policy is that Stereomojo Maximum Mojo awards can only be bestowed by the publisher or by a consensus of more than one reviewer. Therefore, I enthusiastically place the Pacific Valve Modified DAC AM into nomination for our prestigious award.

Associated Equipment

Various Combinations of the following;

Pacific Valve Modified DAC AM (now it’s mine.  $340 on sale)

Bryston B100 SST integrated amplifier

Forte Model 5 amplifier

Niles Passive preamp

Linn Classik

Marantz DV4300 (which died during this review)

Panasonic DVD S25 (surprisingly good transport for chump change)

Nakamichi MB-2s (really old but a decent transport)

Samsung high definition TV tuner

Revel F30 speakers

Magnepan MC1 speakers

B&W ASW600 subwoofer

Several sets of DIY speakers

Cardas Crosslink 1s speaker cables

BlueJeans speaker cables

BlueJeans LC1 interconnects

Monster M1000 interconnects

Power cables from Volex, Belden, and Audioquest NRG-2.

Home