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[This is the second part of a series started in February.  The first part is here.]

A few years ago I took a look at the AC power here at my house on an oscilloscope.  I had done this when I first moved to Yerington, Nevada in 1999 and saw a sine wave with a few glitches here and there.  Now I saw a strange waveform that was far from a sine wave.  To make sure this wasn’t caused by some odd load in the house, I shut off all the power except for the scope, and the waveform was unchanged.  I called my friend Wally in Sunnyvale, California and asked him to check his power, and he found essentially the same waveform.  Here is a waveform I took recently, which is similar to what I saw a few years ago:

What has caused the change over the last ten years?  My theory is that the amount of non-linear loads on the power grid has increased dramatically.  These are almost always power supplies with capacitor-input filters which draw current only at the peak of the waveform, thus flattening the waveform.  The large increase in the use of computers with their cheap switching power supplies as well as the program to replace incandescent light bulbs with CFL lighting is probably driving this.  I saw this “flat-topping” effect on the power line waveform when I worked at Tandem Computers in the 1980s.  The buildings were filled with multi-processor mainframe computers with multiple 1 KW switching power supplies.  However, the waveform at my house in San Jose, in a residential neighborhood, was a sine wave. The waveform I see now is deranged in a more complicated way.

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Clarisonus is about more than just the technology of sound - it includes the enjoyment of music as well.  A site that I’ve been going to over the years epitomizes the love of music: On an Overgrown Path.  It is run by Bob Shingleton, a retired executive from EMI in the UK.  What makes this site so enjoyable is the intensity and depth of Bob’s interests and his concerns about the future of recorded and broadcast music.

On an Overgrown Path takes its name from a piano piece by Leoš Janáček.  Classical music is Bob’s main interest, and he keeps an active eye on the current classical music scene, especially in the UK.  Over the years you see his special interests, including Southern France, music of Morocco and the Maghreb, minorities in classical music, corporate sponsorship of classical music, and the sad state of the recorded music business.  He has an especial grudge with Radio 3, the BBC’s ostensibly classical radio channel.  His complaints are polite and constructive, but you sense behind his writing a frustrated classical music fan who takes the art very seriously.  In addition to his hot-button items, he brings up interesting recordings, reviews classical events, and gives exposure to underdog performers and composers.

Bob Shingleton posts roughly once a day on his site, except for the occasional times where he takes a break for a week or two. On an Overgrown Path has many links to interesting sites, recordings, people, etc.  Oddly, you won’t find the name Bob Shingleton any where on the site; it took some searching to uncover its author.  You can see some interesting information on Bob plus an video interview with him from 2007 at another music site: http://doublebassblog.org/2007/07/on-an-overgrown-paths-bob-shingleton-discusses-blogging-on-video.html.  There is also a link on Bob’s site to a series of podcasts he makes titled “Chance Music“.  On an Overgrown Path is a fascinating and informing site - I highly recommend it.

It’s been over three years since I last described my main home listening system.  There have been several major improvements, which I will describe in this and subsequent posts, but first let me describe what has remained the same.

The speakers are still the old Celestion SL-700s that I purchased back in the mid-1980s.  Their clarity and tonal neutrality are still what keep me listening to them, although they do not have the dynamics and very low-level detail that a good horn system can give.  Their inefficiency (~86dB/W) rules out out low-power amps, but they are quite adequately driven by my home-brew push-pull 300B amplifier, the same since 2004, but with a few small tubes replaced.  They are running on the original Svetlana 300Bs, although the filaments need to be turned on about an hour before the B+, otherwise one of the 300Bs intermittently gets a filament to grid short.  This is a well-know failure of these early Svetlana 300Bs.  I put up with this because I like their sound.

The turntable is the same Randall Museum project turntable designed by Thom Mackris. I had a chance to sand the sides better with a power sander, so it looks better.  As will be explained later, the tonearm and its mounting platform have been changed.  The phono preamp is a prototype Artemis Labs PH-1 that has been used as a test-bed for various design changes.

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Before writing an update on my own “Music Computer” system as well as some of the issues with digital audio today, I want to describe an excellent site for anyone considering using a computer or external DAC to play their music: Computer Audiophile.  This is published by Chis Connaker, out of Minneapolis, Minnesota.  Chris combines digital audio technical knowledge, computer IT savvy, connections in the music industry, and a love of music.  Up until just a few days ago, Chris was the sole contributor to the blog posts, posting usually about once a week.  However, he has just added a second contributor, Kathy Geisler.  Kathy produces recordings and CDs, primarily in the classical music field.  This should add a broader prospective to an already good site.

Even though Chris has, up until a few days ago, been the sole poster of blog entries, most of the action in the site is in the comments area.  There are always the newbies with naive questions, but there are also highly experienced users including key people in the digital audio business, so the discussions are lively and can be highly informative, and are civil, too.  One thing should be mentioned, though, is that digital audio is still going through growing pains and there are always people who like to stick to one opinion or another.  So, when the discussion goes to “how many bits are really needed”, for example, don’t be surprised that someone pipes up saying that the CD Red Book standard is plenty and that 14 bits would suit him fine, too.  Other controversial topics are the sound of digital cables, the effects of upsampling, etc.  This comes with the territory, so, as they say, take these arguments with a grain of salt.  The truth is that there still are a lot of things we don’t definitely know about the defects in digital audio.

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This blog has been quiet for many reasons - writer’s block, travel, work. However, I plan to update the site and resume posting in the near future.  See you soon!

- John Atwood

Here is a site selling DRM-free high-def music that I have been meaning to write about for a long time: HDtracks.  Founded by David and Norman Chesky of Chesky records, HDtracks is an on-line store selling down-loadable recordings - virtually all of them versions of existing CDs or SACDs.  Their catalog has been growing over the last year I’ve been visiting them.  It does not carry the mainstream consolidated labels, such as Sony/BMG, Warner, or EMI, but it seems to have collected some of the best of the independents: check out their list of labels.  Notable for classical music lovers are its handling of symphony private labels, such as the Philadelphia Orchestra, Chamber Orichestra of Europe, Chicago Symphony, San Francisco Symphony Orchestra, and the New York Philharmonic.  It sells its recordings either as complete “albums”, or in many cases, as separate tracks or bundles of tracks.  There is a pdf file of the CD artwork and notes and each track has the metadata already added.

Even though the site is called HDtracks, many of the recordings it sells are from conventional CDs, i.e. 44.1K/16 bits.  The cost of these are $11.98 for the album and $1.49 to $3.98 per track, depending on the track size.  This is not bad, considering that the artwork/notes has already been scanned and the metadata is good. The formats offered for these conventional recordings are: AIFF (Apple’s equivalent of .wav), FLAC, and 320kbps MP3 files.  Note that the AIFF versions have no compression, so they are larger than the FLAC files, which are just as good.

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There has been some news recently on how the FTC (Federal Trade Commision) wants to crack down on undisclosed “sponsored” blogging.  The problem is that some companies pay bloggers to push their product or point of view, without disclosure.  This corrodes the trust that the public has in bloggers in general.  Since products, companies, and web sites are often mentioned and reviewed in the ClariSonus blog, I want to clarify the position of ClariSonus regarding sponsors and independence:

The www.clarisonus.com/blog site is supported personally by John Atwood, and accepts no advertising, sponsorship, or any other financial support.  In the future, if needed, individual donations may be accepted (such a through PayPal), but there will be no strings attached.

Product reviews are done solely one the basis of the point of view of the reviewer and are not done in conjunction with or even with the knowledge of the company or product reviewed. Companies are free to comment on a review, but any commenters that are found to have an undisclosed sponsorship related to what they are posting will have their comments removed.

Authors of ClariSonus posts may have financial interests in products or organizations mentioned in their posts. These interests must be disclosed, either in their introductory biography or in the post itself.  Authors for ClariSonus are chosen for their independence and integrity to avoid conflicts of interest.

The Privacy & Legal page on this site has been updated to reflect this policy.  This is not a change in policy but rather a clarification of what we have always done.  As a reminder of my own financial interests, I get royalty payments from Artemis Labs for the designs I’ve done for them and get royalty payments from Antique Electronic Supply for the One Electron line of transformers and chokes sold there.  I do occasional consulting jobs in the consumer and pro-audio business, and these jobs will be mentioned if relevant to an article or review.

- John Atwood

You may have wondered about the lack of blog activity for the last few months.  Nothing is wrong here, other than a heavy case of writer’s block and procrastination (the latter an Atwood family tradition). I’ve been working on projects around the house and have been busy digesting a huge pile of distressed electronic parts and equipment picked up at an estate sale.  Two other recent acquisitions include an old lathe and milling machine, so I hope to soon start building some mechanical parts - mainly for my electronic projects.  In any case, I hope to resume activity on the blog.

Over the last two months, I’ve noticed an increasing number of new user ids being created on the Clarisonus blog.  These all seem to have spam-like names and many come from Russia.  The only reason to create a user id on the blog is to be able to post a comment.  Since there have been few comments recently, the new user ids seem suspect.  To keep the blog database from getting clogged-up, I’ve deleted any suspicious-looking user ids.  If I have inadvertently erased your legitimate id, I apologize, but all you have to do is recreate it if you want to post a comment.

Loudspeakers for Music Recording and Reproduction, by Newell and Holland

There are a number of cookbook and do-it-yourself guides to building loudspeakers, but few aimed at experienced builders and those already in the industry. And no, you can’t find everything on the Internet, and separating the gold from the dross of PR-speak “white papers” in the AES Journal pre-prints is a major project in itself.

If you are interested in high-efficiency, high-headroom loudspeakers and how they are used in modern studios, this is the book to get. More broadly, if you are interested the key technical parameters that affect the subjective listening experience, this is one of the few books that has a rigorous and comprehensive coverage of the subject, backed by the two authors’ decades of experience in professional audio. Dr. Keith Holland is a lecturer in electro-acoustics at the Institute of Sound and Vibration Research at the University of Southampton, and Philip Newell is an international consultant on acoustic design with over 40 years of experience designing hundreds of recording studios (this is his fifth book on professional audio).

In addition to loudspeakers - which are covered by an introduction on acoustics, and moving on to separate chapters for the main types of loudspeaker design, loudspeaker cabinets, horns, and crossovers, there are chapters on amplifiers and cables, loudspeaker behavior in rooms, interfacing loudspeakers with the rest of the studio, subjective and objective assessment (with particular attention to the effects of phase delay at low frequencies and the midrange), challenges in low frequency design and the effects of these choices on transient response, and a final chapter on surround sound.

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What happens when history falters? When brilliance is forgotten?  When a brilliant mind dies tragically in obscurity and secrecy? This is essentially what happened to Alan Dower Blumlein, a British electrical engineer who developed many circuits and concepts we take for granted today, yet is barely known.  This obscurity was compounded by a confluence of bad luck and unfortunate behavior which delayed the first biography of Blumlein until 57 years after his death. I’ve just finished reading one of the two biographies that appeared in 1999: The Inventor of Stereo: The Life and Works of Alan Dower Blumlein by Robert Charles Alexander.

Blumlein was truly an electronic genius, at least at the same level as Edwin Armstrong, yet had the bad luck of working in a company (EMI) that didn’t encourage publication (Blumlein only published two papers in his career) and discouraged publicity (only four photographs of Blumlein are known to exist), and died while working on an extremely top-secret project (centimeter radar) during World War II, resulting in his war work being buried in secrecy. His only tangible legacy (other than his designs and inventions, which were widely used) were his patents - over 120 of them - which trace the path of his short career.

Here is a thumbnail summary of Blumlein’s life and accomplishments:  He was born in London in 1903 of an Alsatian father and South African mother (of Scottish background). He was an intelligent child, but only learned to read at age 12 when he realized this was important.  He picked up an interest in electricity as a child, which lead him on a path to a degree from City and Guilds College in London, a respected technical branch of Imperial College. In 1924 he got a job at International Western Electric (later to become S.T. & C.) analyzing telephone line cross-talk.  As part of this work, he invented a balanced bridge that allowed sub-picofarad capacitance measurements on phone lines, which greatly facilitated efforts of cross-talk reduction. He also developed very sophisticated compensation networks for buried and undersea cables.

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The lifetime journey of an audiophile can be long and varied. From the first music you heard as a kid on a hand-me-down radio to the hair-raising experience of hearing a world-class esoteric audio system, the enjoyment of music can still exist at all levels of audio reproduction. If the sound you hear is the result of what you make with your own hands, an even higher level of satisfaction results. In a world where manufactured devices come from a far-away land and are increasingly dense and disposable, being able to make and control a key aspect of your musical enjoyment is a precious ability.

There are many reasons why DIY (Do-It-Yourself) audio is feasible and enjoyable:

• The human ability to process and enjoy sound is extremely complex and not fully understood. Subtleties in the reproduction of sound can enhance (or detract from) our enjoyment and these subtleties are often under the control of the experimenter.
• Old analog recording and amplification techniques from 50 or even 75 years ago still provide incredible musical enjoyment. These techniques can be readily constructed by a skilled amateur, unlike, say, movie or video techniques.
• Unlike someone interested in chemical experiments, electronic experimentation is free and uncontrolled (so far) and old surplus electronic parts and equipment are readily available, allowing experimentation on a budget.
• Some aspects of audio reproduction, such as analog amplification and mechanical design, are accessible to the amateur.  Fancy college degrees or expensive industrial equipment are not required.
• There are many facets of audio reproduction, each with a deep history and technology, allowing almost unlimited fields of exploration for the inquisitive mind.
• With sufficient knowledge and skill, it is possible to build an audio system that sounds better than any commercial system available.

The result of these is that home-built or -modified audio equipment can be a fascinating and enjoyable hobby.  However, my appreciation of this has been dulled over the last few years as I have become more involved in consulting on commercial designs (mainly for Artemis Labs), and the increasingly high-quality, and in some ways, uncompromising high-end systems I have been exposed to. When your audible senses have become fine-tuned and almost any system shows various flaws, it is easy to fall into a superior, dismissive attitude to lesser systems. I have never been a believer in the one, ultimate “absolute sound”, but I was beginning to adopt an elite attitude about audio equipment, thinking that most systems “sucked”.  This attitude is readily reinforced by attendance of trade shows like the CES where (for a variety of reasons) the vast majority of the sound actually really does suck.

I had a pleasant reminder of my DIY audio roots, however, during a recent visit to Thailand, where my friend, Kamon, spent a day to bring me around to visit various audio DIYers he knew in Bangkok.  For example, here is Kamon and Mr. Pae (described in my posting from October 2007) discussing the system in his house in the outskirts of Bangkok:

Note: The following pictures can be seen at higher resolution if you click on them.

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For the first time in three years I attended the Consumer Electronics Show (CES) as well as the concurrent T.H.E. Show in Las Vegas. The CES has been the largest trade show for the consumer electronics industry in America for years.  It used to alternate between the coasts and Chicago, but the main show has been in Las Vegas since at least the mid-1980s, when I first attended it. This posting will give my overall impression of these shows, with no guarantee of completeness, fairness, or impartiality.

The bulk of the show is in the huge convention center halls and in the Sands Convention Center - the size and crowds earned this part of the show the name “the zoo”.  Showing off high-end audio requires acoustic separation between vendors, and the usual way to do this is to set up the equipment in hotel rooms that have had their beds removed.  As a result, the high-end audio part of CES was always separate from “the zoo”.  Over the years, dissatisfaction with the CES management plus the high cost of rooms caused an alternative show to be created: “T.H.E. Show” (The Home Entertainment Show). Up until 2007, the high-end audio part of CES was held at the Alexis Park Hotel, off the strip and quite far south of the convention centers.  T.H.E. show was held in the adjacent St. Tropez hotel, so it was easy to walk between the two high-end shows.  Both of these hotels are low-rise “garden”-style designs, spread-out, with no casino or slot machines (!). However, in 2007, the CES moved the high-end exhibits to the upper floors of the Venetian, a huge hotel/casino right on the strip, and part of the Sands complex.  T.H.E. Show then moved into the Alexis Park, which, although nice, was a long shuttle bus ride from the Venetian.  The slow economy has reduced the number of exhibitors, especially at T.H.E. Show, and lots of people I met at the Venetian didn’t even know of the existence of T.H.E. Show or didn’t spend the time to visit it.  It’s too bad, since I found the Alexis Park much more relaxed and convenient than the Venetian.

One of the first things you see when approaching the Alexis Park is this remarkable steel sculpture that plays music and follows you around! It is the creation of Solar Sound Sculpture, basically two men from the San Francisco Bay Area who work in an old steel shop in Oakland along with other large-scale sculptors.  I had a good talk with Justin Grant who built most of the sculpture and he explained that this had initially been shown at the 2008 Burning Man festival.  The speakers on the top have infrared sensors and servos that make the speakers track the closest person.  It is huge - at least 20 to 30 feet tall, and quite striking.  It can be run off solar panels, but in this set-up was running off storage batteries. Very impressive!

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