Monthly Archives: April 2013

System Upgrade Part 4: DacMagic

As many know, I really do not care for the sound of digital.  Not all digital–DSD (via SACD) is fairly nice, and higher resolution files tend to reduce the characteristics of digital sound which I do not care for.  With standard CD-grad digital, however, I can hear the low resolution.  At higher frequencies, a raw digital signal looks like a sawtooth in comparison to the analog original…and I have heard this, especially when in close proximity to a speaker.  The highs have a “buzzy” sort of sound to them that no amount of digital filtering or dithering can cover up.

cambridge-audio-dacmagic-convertor-digital-analog-2522454[1]I was relying on the DAC (digital to analog converter) built into my Pioneer Elite DV-45A for all these years.  As it is a “premium” player, I had expected somewhat better sound out of it.  SACDs do sound nice, as do some of my DVD-Audio titles.  Yet I found that as I was listening to CD digital, I was unconsciously grinding my teeth.  Not only that, digital seemed to always have a constant “glare” in the upper mids that seemed to make the sound cold and lifeless on many titles.  And the older the CD, the worse the sound–many of those early reissue titles sound absolutely horrid, many unlistenable.

The Musical Fidelity X10-D tube buffer stage did help the digital output greatly, but that was one of two steps I was contemplating.  The other step was to get a mid-range DAC to try in the system.  And now that I have a Cambridge Audio DacMagic on hand, I have heard what a DAC can do for a system.

The DacMagic is not without its quirks.  And, I am having issues with sources of my own that are preventing me from hearing all of my PCM digital through the DAC.  (For example, the DV-45A does not output 88.2kHz digital through the digital outputs!)  The WDTV Live Streaming Media Player I purchased also turned out to output signals only at 44.1kHz or 48kHz, so I still have no way to listen to my high-res FLAC files.  Shameful.  I can go as high as 96kHz/24-bit using an outboard USB sound device on the laptop, but that defeats the purpose of having a media player that handles these issues simply.

Anyway, that debacle will be solved in a future installment.  For now, back to the DacMagic.  My main question in all this: would I be able to hear a difference?

Turns out, I do hear a difference.  Comparing the output of the DV-45A to the DacMagic, the DV-45A has a thinner and less musical sound.  The DacMagic is fuller and has more body, especially on primitive CD-level sampling rates.  It does a credible job of getting inside the music and making CDs (and 44.1kHz/16-bit FLAC files) sound better than they have any right to sound.

Is the combination of the X10-D tube buffer and DacMagic DAC too much?  No!  If anything, the two are complementing each other.  The DacMagic smooths out and makes the digital more musical, where the X10-D adds a certain fullness, warmth and imaging quality that makes the music bloom beyond the speakers.  The two sound very nice together, and it is understandable that some companies offer a DAC with a tube output buffer stage–I find it to be a very pleasant and musical case of synergy.

Music through the DAC/buffer combination often create moments where you are distracted by the music, stopping to listen to something you may not have noticed in a familiar piece of music.  Some vocals over the combination are almost goosebump-inducing now, and acoustic music really shines.  Something like the Bill Evans album Waltz For Debby (which I actually play from an audio DVD at 24-bit/96kHz) really gives you the experience of being at the Village Vanguard when it was being taped.  Michael Franks’ voice is also in top form; on The Art Of Tea, you get the fullness of his voice without the “chestiness” that muddies the sound.  Recordings that could lean toward sibilance are tamed down into listenability.  Even older recordings, such as Cal Tjader’s Several Shades of Jade, bring out the detail and space between all of the percussion instruments.

While the DacMagic is good, I am looking to upgrade to a DAC that will take a full 192kHz/24-bit and 176.4kHz/24-bit source.  Cambridge has newer products that can handle it, and the Schiit Bifrost is also a nice unit in a similar price range that can tackle all those sampling rates.

After that, I need to tackle finding a media player than can play back the pure FLAC files as is, without any downsampling or digital processing (including a volume adjustment in a media player).  Short of playing music from a laptop, I do not even know if I can find what I need at a price I can afford.  In other words, for simple processing of FLAC files into a direct S/PDIF signal, there should be minimal expense involved (not something in the four figure range, in other words).

It’s been awhile since I’ve pulled out stacks of CDs to sample, and this tube buffer/DAC combination has had me doing it.  The whole experience so far shows that I really could stand to do major upgrades to all of my components, but the budget is not there as of yet.  If a player like the Oppo BDP-105 had a suitable analog output, I might be tempted to bypass using an external DAC. And rather than a tube buffer stage, I might be inclined to find an Audio Research SP-10 or SP-11, both of which are tube-driven.  But for now, I have a sound that is more listenable than back when I started on this mini-quest.  Mission (somewhat) accomplished!

The epilogue: if I had to recommend a component to improve digital sound noticeably, what would I recommend from the components I’ve tried?  It’s true that the DAC made noticeable improvement, but the tube buffer is actually what gave me the biggest boost in listening pleasure, along with having the advantage of being able to try different sets of tubes to affect the sound.  The buffer just gave the whole presentation a lift: imaging, body, fullness, properties I felt were somewhat lost with digital playback.

System Upgrades Part 3: swapping Hafler preamps

For the past dozen years or so, I have been using a Hafler DH-110 preamp in my system.  Functionally it does not offer much that my older DH-101 doesn’t, other than an extra set of outputs.

Along with my other upgrades, I decided to swap the DH-101 back into my system.  Having read some accounts online, many audiophiles still remain impressed at how good of a preamp the DH-101 is.  I built this DH-101 back in  1982, and the leap forward in sound was amazing at the time.  Having swapped it back into my main system, I am pleased to say it sounds as good as ever.

One comment about the DH-101 is that the background is very “black”.  This means that the music comes out of virtually total silence, adding no noise to the music at all.  Granted, I can crank the volume all the way up and hear some sort of hiss or hum, but my power amp would turn itself off at half the volume setting.  Even after years of non-use, the “blackness” is still there, even though the capacitors are over 30 years old now.  Upgrading the caps might be an option in the near future, to freshen up the preamp to original specs.  But until then, it is sounding awfully good.

In comparison, I now feel that the DH-110 sounded different–perhaps a bit softer or even duller.  The DH-101 seems more precise, more immediate, but not exactly brighter per se.  A buddy of mine way back then commented about my then-new DH-101:  “Damn, that bass is tight!”  We were spinning the Earth Wind & Fire Raise album at the time, and the bass was just totally on cue, whereas the hacked integrated amp I previously used just sort of slurred the sound all together.  The DH-101 gives me more inner detail and to me, seems to breathe a bit better through the midrange than the DH-110.

433105-no_2_david_hafler_dh101_preamp[1]One annoyance of the DH-110 is the detented volume control.  This is not a stepped attenuator, but just an extra wiper on the potentiometer that makes the control operate in steps as opposed to a smooth transition.  The problem, though, comes with newer components that have such a high output that it is nearly impossible to get a low volume that you are comfortable with since the correct volume is between steps on the volume control.

The rotary switches were also becoming more corroded in the DH-110.  I had done a full strip-down a couple of years ago and sprayed all of the switches with deoxidizer, but the frequent channel dropouts in recent months drove me to finally retire it for the time being.  I would probably press it into service in a second system at some future point, perhaps even replace the capacitors and see if the sound improved.

The DH-101 has been a nice fit with the tube buffer and the change in speakers. It is much like having a familiar old friend back in the system.  I have toyed with building a tube buffer stage into the preamp, as it would just fit the space provided.  That would really take it over the top!  I would, of course, offer an option to bypass the buffer if needed.

One thing that disturbs me is the poor condition of the RCA jacks on the back.  But, I have a cure for that, and it may be something I can market via this website: an upgrade that many have hoped for, but few (if any) have attempted.

There is one more system upgrade coming…stay tuned!

Bobby Troup and His Stars of Jazz: a swinging romp through the past!

Bobby Troup And His Stars Of JazzI took a chance on this one. About 15 or so years ago, I had to pad out an order for some BMG Spain import titles. Along with some assorted other west coast jazz CDs, I grabbed this one. I was not let down at all: this album features the cream of the crop of west coast jazz musicians! The Candoli brothers, Plas Johnson, Bud Shank, Frank Rosolino, Jimmy Rowles, Shelly Manne, Monty Budwig, Mel Lewis, Red Norvo…and plenty of other familiar names. The album was recorded in Hollywood on three dates in late 1958, and features the arrangements of Jimmy Rowles on eight of the tracks, with Shorty Rogers contributing the remaining four.

What this album is NOT: a soundtrack album. If the name “Stars Of Jazz” sounds familiar, Bobby Troup hosted a television series called “The Stars of Jazz” back in the late 50s. While there were a great many performances from that series (some of which are now available on DVD), this album is a related but different project: a showcase for Bobby Troup’s dusky vocals set against a swinging west coast big band. The song selection is varied: it ranges between popular standard songs such as “Sent For You Yesterday”, “Oh! You Crazy Moon” and “I’m Through With Love” and lesser known tunes. Shorty’s contributions include clever swinging arrangements for “Take Me Out To The Ball Game” and, believe it or not, “Tiptoe Thru The Tulips With Me” (before it was even a glimmer in Tiny Tim’s eye).

The band’s performance is top notch. I also have a feeling that given the number of musicians, the recordings may have involved either a rotating lineup of musicians in each band, or two different (but still “all-star”) big bands. The Shorty Rogers tracks sound like something right off of one of his Giants albums. It is all so cohesive, though, that it serves to showcase the great ensemble work these musicians were all capable of. As for Troup’s performance: he is no vocalist that is going to turn heads with dazzling technique. But what he lacks in ultimate polish and technique, he makes up for with an easygoing attitude and enough jazz chops to demonstrate that he “speaks the language” of jazz. And surprisingly, all piano duties are handled by Jimmmy Rowles–Troup sits out the piano in favor of vocals on this project.

Quite enjoyable, and quite recommended! Especially if you are a fan of west coast jazz or any of the fine musicians who were a part of that 50s/60s scene.

System Upgrades Part 2: swapping the Grafyx SP-10 speakers

Shortly after receiving the Musical Fidelity X10-D tube buffer, I felt I needed to upgrade the other components.

When the tube buffer arrived, I took the opportunity to also swap out my speakers.  In an earlier post, I extolled the virtues of the Grafyx SP-10 loudspeakers I own.  I had previously swapped out, then sold, the Boston Acoustics A-150 speakers I had paid only $30 for.  I enjoyed them, but felt the bass was a bit constricted due to having refoamed the woofers.  The mids were also not as smooth as I would have liked.

The Grafyx SP-10W pair of speakers I bought circa 1982 have identical componentry to the SP-10 pair I bought back in 1978.  The cabinets differ: the older pair uses vinyl veneer, whereas the “W” designation put nicer moldings on the front and covered the whole thing in genuine walnut veneer.  The emblems were upgraded to cast bronze, and the grille cloth was black as opposed to what I’d call a dark chocolate brown.  I had rewired them with far better OFC wiring.  They look nice!

Yet, I always felt they were not as good sounding as the original pair I bought.  It was time to swap the pair, and see if I really noticed a difference again…and indeed, I have.

The tube buffer has its own charm (the full write-up is in Part 1 of this series), but this pair of speakers is, to me, much more musical.  It is like the tube buffer: the change is subtle, but noticeable.

I still feel the mylar dome tweeters could use some minor improvement.  In fact, there are some cloth dome versions still out there in the wild.  Since the voice coil unit can be removed and swapped between magnets, I may locate a pair of the cloth dome tweeters and try them in this system.

The bass might be a little smoother in this older pair, yet it still extends quite deeply.  That is the charm of the SP-10 when I first heard it against the Polk Audio Monitor 7: the bass just extended much deeper.  In the right room, you can get clean response down to 32Hz (a low “C” on the scale).

So, what are the differences that make me still prefer this older pair?

First of all, the midrange.  It always seemed as though the newer SP-10W set was a little brighter and had a little more boom to the bass; turns out that what I’m really hearing is a fuller midrange in this older pair.  And it really hits a nice sweet spot!  These are the pair that the old $ensible $ound magazine raved about.  What I notice is a nice, full sound to the system–it just seems to meld together nicely.  In the newer pair, it now seems like the sound was disjointed–highs, lows, but no full midrange that really glued the whole spectrum together.

In addition to that midrange, it seems as though this pair images the soundstage better.  Perhaps the enhanced midrange helps pinpoint the locations of the individual instruments.  Or, it could be the cabinet construction.  The speakers likely have the same or very similar internal dimensions, but the SP-10W is about 1-1/2″ wider across the front, while the cabinet depth may be about 1 inch less at the most.  Both pairs have the baffle board on which the tweeter is mounted, which places it flush with the speaker grille and eliminates diffraction.  The edges of the older pair are slightly beveled, where the SP-10W were squared off.  The tweeters are identical.

And speaking of the imaging, I still do notice some of the “vertical blind” effect if moving from side to side.  I blame this on the tweeter’s plastic enclosure–it is concave, with a disc and six supports over the top of it.  While I do not want to remove the protection this provides, I often wonder what a similar dome tweeter would do for the sound, or even a ring radiator.  Yet, changing the tweeter unit would alter the sound of the whole system, and would require crossover modifications.  More on that shortly.mx4jbbJeW5mtmoXwC15X7CA[1]

The sound, in tandem with the tube buffer, really blooms.  I hear a fullness beyond the range of the left and right speakers, yet the focus of centered voices and instruments appear dead center–the proverbial “phantom center channel” sounds more solid than I ever remember hearing it.  Voices, especially those of alto-range female vocalists, sound superb, as do acoustic instruments like the piano, which seem to hover in space now.

I have often wondered why these two sets of speakers could sound so different.  Yes it’s subtle, but over time I start being fatigued by the newer SP-10W pair than I do the originals.  One issue I had with my older pair is that the tweeters gave out.  These shipped from Grafyx with the Philips AD-0162T8 tweeters.  Madisound Speaker Components used to stock these replacements for about $12 each, and I ended up purchasing the AD-1624T8, which was the identical tweeter but with ferrofluid cooling in the voice coil gap.  I wish now I had purchased the AD-0163T8 soft domes instead, or in addition, so I could experiment.

But why should the tweeters matter?  I have two theories regarding the change in sonics.  First, I thought that Grafyx may have wanted to add a little more “sizzle” to the line by goosing the lower and upper ranges by reducing the midrange slightly.  However, one other idea came to mind much earlier: the tweeter crosses over at a somewhat lower frequency, and I suspected that Grafyx may have changed the crossover point to reduce warranty claims or give the tweeters a longer life.  It’s a moot point at this stage, 30 years later, but those are the only two reasons I can think of for re-voicing the system.  I may at some point rebuild the crossovers with fresh capacitors, but I will also take note between the two systems to see if any of the values were changed on the crossover boards.

Until I get the Sequel IIs in the listening room, though, these older SP-10s are doing nicely.  I can’t help but recommend them highly, especially for the money.  You end up with a cabinet about the size of the Large Advent, but without the many downfalls of that speaker (including the Advents’ finicky “fried egg” tweeter, and the woofers with the fragile voice coils that are pretty much goners if they even think about bottoming out).  And these image far better than my Small Advents ever could.