Audio 2013

Audio 2013
January 13, 2013

I used to talk from time to time about some of my audiophile pursuits. I thought I would update this a bit.

June 21, 2009: Summer Slack-Off 1: Headphone Audio
August 24, 2008: Five Audio Systems
July 15, 2007: Give Yourself the Gift of Music

I like music. If you like music too, it is worthwhile to arrange things so that you can have satisfying music reproduction in the home. This is more complicated than it sounds, especially since so many can get lost in a miasma of gear-twiddling. Here are a few things I’ve learned over the years.

These days, there are really only a few “modalities” which I find are the most productive. One is the high-efficiency horns route. Another is the dynamic driver on open baffle, often a wideband or full-range item. The third is headphones. I’ve done all three in style.

For a big horn rig, I once had some RCA “Ubangi” bass boxes, with twin Altec 515s per channel, topped by a 5-foot-long 200hz horn run with a pair of Western Electric 720a drivers per side. This was driven by some 45 SET amps, with an interstage-transformer-loaded 10Y doing driver duties. The efficiency was around 110db. This was really splendid. I would enjoy having a big horn rig again sometime. I couldn’t find a buyer in the Northeast for the wonderful RCA “Ubangi” cabs, even at a price ($1500) barely above the value of the Altec drivers alone. This just goes to show how few people in the U.S. are on the hunt for the real audio goodies, as opposed to $25,000 shoeboxes from Magico or YL. The RCA basshorns ended up in Hong Kong. It cost $400 just for custom crating. The sofa-sized beasts shipped on two pallets.

For an open-baffle rig, I had some 8″ field-coil Fertin fullrangers, with a pair of 15″ woofers per side for bass. One fellow, who had heard some very ambitious systems in his New York City audio club, called it the best-sounding dynamic driver setup he had ever heard. This was even when it was being driven by a $125 Tripath amplifier. This is a very good way to go for a smaller space, less than 400sf for example.

For the last four years, I’ve been listening to headphones exclusively. We also have a “kitchen system,” which consists of some Fostex 120A drivers in boxes, plus a subwoofer, but that is more of a “fun” system than a serious one.

Headphones are really one of the best ways to go about this process. That is one reason why headphones have been a hugely popular corner of the audio arts over the past ten years or so. You can put together a stonkingly good headphone rig for $2,500, which barely gets you anything at all in terms of normal speakers. You can listen to any kind of music, at all hours, without bothering anyone. You don’t need a separate room, or room treatments, or all the other stuff that tends to go along with more ambitious speaker systems. Plus, headphones are by nature a lot simpler. Usually, they are single fullrange drivers, and superefficient at a typical 97db/mW (that’s milliwatt). We don’t have the constant battle between refinement and power, simplicity and complexity, that characterizes regular speaker/amplifier approaches. Sometimes I daydream about something like the Danley SH-50s, with a multi-amp setup and a digital crossover. Then I think — too much bother!

I’m using Sennheiser HD600 headphones, with the Cardas “smurf” cable. I’ve had these for about ten years. They are not very fashionable today. But, they “sing” in a way that some headphones, which are supposed to be better, do not. This is not a bad way to start, especially since you can find them used for about $300, with the aftermarket cable. Maybe I’ll try the Sennheiser HD800 this year, and maybe I’ll find that I don’t like it as much. I experimented with a heavily-modified Denon AH-D2000, at roughly three times the price of the Sennheisers, which the creator says surpassed even the legendary Sony R10s that he owned for seven years. For me, I couldn’t get this to work at all, with much break-in and several amp combinations. The lowly Sennheisers crushed them.

Headphones are clamped to your head, and benefit greatly from refined amplification. I have a few items here: one is my homebrew 01A-71A SET amplifier, with battery power on both filaments and plates. This is a rather exotic beastie, weighing about 200 lbs in five boxes (amp, battery, separate TVC, two battery chargers). It took me a while to dial this one in properly. The result sings wonderfully, especially on the Sennheisers.

For comparison, I also have a Bottlehead Crack headphone amp, fully tuned with CCS boards. This is an all-tube design, with a 6880 cathode-follower output. This does not have the same level of refinement, but those Bottlehead guys have good ears, and it gets you pretty close in a muuuuuch smaller chassis and much lower level of complexity.

I also have the headphone output of the CEntrance DAC mini that I’m using for digital duties here. It is supposed to be a class-A jfet output of some ambition, but it leaves me cold and uninvolved. I would like to try a few more solid-state amplifiers, but in general I find that I prefer tubes, and vintage SETs in particular. It would have been convenient if the one-box CEntrance unit could replace my piles of tube gear. No luck.

Vintage directly-heated triodes, those vacuum tubes from the 1930s, took the audio world by storm in the 1990s. They are not so fashionable today, due to their high costs, low power, and limited bandwidth. However, after listening to many alternatives, I find that they still sound the best by a large margin. On speakers, I generally prefer SETs on horns. With 110db horns, that 45 can really sing. On headphones of course, power is not an issue. I would be interested in hearing some of the more refined contenders such as Nelson Pass’s SIT amplifiers or the Burson headphone amplifiers. In fact, I’m experimenting myself with solid-state headphone amplification here, with a single-stage, no-feedback jfet-based amplifier for headphones that I call the “Beast of Ten JFets.” (You would have to be familiar with Nelson Pass’s work to get that one.) It is basically my headphone version of Pass’s SIT amp, with a single 92 ohm resistor used as a load. Of course it is a Shinkoh tantalum. Power will be supplied by a pair of 12V batteries.

Digital-to-analog converters have made huge strides in recent years, and there are a lot of good items out there now for less than $1000. The CEntrance unit was a huge step above the DIYParadise “Monica” DAC I was using previously. These days, it’s pretty much a USB-to-DAC world. I packed up my vinyl turntable (a Micro Seiki unit purchased 27 years ago) and put it away in the barn for a while. I bet you could find a better unit than the CEntrance, for the same or less money now.

My suggestions today: go with triodes and horns if you want a big speaker rig. If you want a smaller speaker rig, go with widebanders on an open baffle. I could have a lot of fun with simple FE103s on open baffle, crossed around 200hz to some cheapie Parts Express powered subwoofers — especially in a small room. I would power this with a 300B amp or perhaps a Gainclone amplifier. I would also try the Hypex NCore 400 boards, but my investigations in Class D in the past have been rather disappointing. The DIYParadise “Charlize” Tripath amplifier, which is a pretty good one for its breed and in this case battery-powered, was nowhere near as good as a Gainclone and not in the same universe as my modest 2A3 amps. I listened to the NuForce Icon in the kitchen system for years, and recently replaced it with a $200 Chinese tube amplifier from eBay. The little Chinese job is only about a hundred times better.

I admit to having a soft spot for vacuum tubes, on the principle and style of the thing. This is a little like those who insist on Harleys even though the Japanese bikes are better in every technical sense. But, on top of that, they also sound better.

For headphones, I suggest starting with the Sennheiser HD600 or HD650, which are available used (try for not much money. Even if you later go to something else, this will provide a good frame of reference. The Bottlehead Crack amplifier is a great pairing for this. You can get this as a kit, but I would have it built and add the CCS upgrades. For a source, you have a lot of options, and I would look at the recent reviews at for some ideas. The Asus Xonar Essence Muses sounds interesting. CEntrance also makes DAC-only devices that are quite inexpensive. You give up the headphone stage and preamp functionality, but as I mentioned these are not that great anyway. The digital and USB stages are identical, and it’s less than half the price.

The Audirvana music server was a surprisingly huge upgrade in 2012 — by far the biggest advance of the year. Use it.

The other big advance of the year is Spotify. At $10 a month, you get access to an immense library of music. Yes, it is on MP3, but at 320kbps at least. No, it does not sound as good as 24/96 or even 16/44 over Audirvana. Not nearly. But, it is still maybe good enough — especially for those recordings (all pop) which are themselves rather low-grade at best. Spotify is undermining my audiophile ambitions, as the lure of new music instant gratification overwhelms my distaste for the MP3 sound.

The combination of a used Sennheiser HD650 with Cardas cable ($350), Bottlehead Crack ($600), and CEntrance Dacport LX ($250) comes to $1,200, which is pretty small beans for admission into serious audiophile territory. (Note that the Crack amplifier is only compatible with high-impedance headphones.) I would also consider the new Burson Conductor, which puts DAC and amplifier into one box for about $1,900. Apparently it is pretty good, although I would want to hear it myself before handing out accolades. After the modded Denon experiment, I have learned that what other people like and what I like can be completely different. Also, my success rate with solid-state gear is rather low. I remember all the gushing that accompanied some Class D equipment, but I’ve never been able to get it to sound good.

The Asus Xonar Essence Muses ($899) is another one-box solution at a lower price point, also very well regarded.

Add Audirvana ($49) and, eventually, a decent USB cable (Audioquest Cinnamon $60, Elijah Audio quad $200). If you’re smart, you’ll just stop there and enjoy the results for about three to five years.

UPDATE: After reading recent articles by Lynn Olson, who I have followed for years and who has a similar approach to mine, I decided to get a new DAC based on a NOS R2R architecture. Today, there are only a half-dozen or so such designs available, and fewer than that under $2000: basically the PCM1704-based Monarchy NM24 (a monster value at $1050) and the Metrum Octave ($1500). I got the Metrum Octave, used.

This is nothing new for me. I point-to-point wired a “Kusunoki-style” 4x TDA1543 DAC back in 2001, and enjoyed its fresh and languid style immensely, although I later concluded that it was somewhat crude. I later tried several attempts at DIY-ing a TDA1541-based DAC, which showed great promise, a far more elegant presentation than the TDA1543, but were buggy and problematic. I decided that DAC-building was not for me. I moved on to the TDA1545-based DIYParadise Monica DAC, the first USB-input DAC. This was also pretty good, although rather simple and somewhat crude, and disadvantaged by a first-generation USB input and a jfet-based output stage. These are all NOS R2R designs. The CEntrance DACmini, a delta-sigma design, was much more refined than the Monica, and replaced it. At that time, I was valuing the clarity and even-handedness of the CEntrance, the far superior USB input and the ability to go to 24/96.

Following Olson’s suggestions, the Metrum went in and immediately showed much more life, color, ease and grace than the CEntrance. This is a major step forward for me — the first refined NOS R2R design I’ve had, since I missed the boat on the TDA1541-based DAC years ago. Plus, it goes to 24/192 which the TDA1541 never could. The Metrum is more expensive, so you would expect it to better. However, it is not just a matter of price — Olson says that the characteristic delta-sigma sound is present at all price levels, even $10,000+.

Going forward, I see no reason to stray from anything but the NOS R2R architecture. There is simply not enough time to make more mistakes. This is analogous to my own fondness for antique directly-heated triodes in single-ended or no-feedback push-pull configurations. They are expensive and problematic, but the tone … ! There are many other options, but I can say that after a decade I’ve never found anything that sounds better, within their rather considerable limitations. It is all just as Dr. Gizmo said years ago: King Tone. The Metrum has it, the DHT SETs have it, and the Sennheiser HD600 has it.

Like Lynn Olson, I think that most reviewers don’t even hear this stuff. They don’t really have experience with it — even those who have owned DHT SET amplifiers in the past. They are compromised by delta-sigma DAC sources, or inappropriate speakers, or maybe they just never clicked with it.

The combination of Audirvana and the Metrum DAC has been a gigantic leap forward for me, and really reveals the lucid majesty of the (super pain-in-the-ass) 01A-71A amp and Sennheiser headphones that I put together over a decade ago.

If you want something simple and a super value, get the Monarchy NM24, and some used Sennheiser HD600 or HD650s. The NM24 can drive the headphones off the preamp output. I would use USB input via the M2Tech Hiface 2 USB-SPDIF convertor, since the NM24 has only an SPDIF input. Total cost would be about $1700, less if you can find a used NM24.