Ho! Ho! Ho! And a Merry Christmas, or whatever holiday you celebrate, to all. It's that time of year to thank G-d that the elections are over and the commercials have reverted to selling us product rather than politicians. I'm writing this in October, so I don't know the election outcome as yet, but I pray that it was a clear win for one or the other and not what we've gone through over the past three elections.
Anyway, it is that time of year when I make suggestions for audiophile presents for both giving and receiving, and even treating ourselves to some with whatever funds are left over after the Christmas buying season. Of course that is also dependant on whether we have any funds at all considering what the financial system is going through in October and how my retirement fund has shrunk to 1997 levels. Thus one product that costs nothing. Then I'll discuss a new single ended amplifier circuit from Jack Elliano of Electraprint Audio of Las Vegas.
First off I have to make a proclamation: HD-DVD is dead, and SACD and DVD-Audio are on their deathbed, having been beaten by Sony, of all companies, with their history of loss of standards battles (think VCR vs. Beta.) Long live Blu-ray. While Blu-ray concert discs are still few and far between and at this point there is still not one Blu-ray player that is built to the complete 2.0 standard or will play every Blu-ray disc out there faultlessly, and none yet that will play SACD, supposedly Sony's Gold Standard for music, the several discs I've been able to find of classical concerts prove that DTS-MA coding can deliver audio quality equivalent to SACD or DVD-Audio.
On the other hand I have found a couple of Blu-ray recordings which cannot be recognized by my Samsung HD-DVD, Blu-ray player but are by my home theater computer with Blu-ray drive as readable. Second, there are two others where the recorded sound is less than exemplary, probably due to either a poor recording engineer or sloppiness in the mastering process, showing once again that in recording, garbage in, garbage out prevails. So here are my picks for Great High Definition Recordings of the Year and great Christmas presents:
Violin Concertos 3,4,5
Electraprint Audio EP-SEA2 Tweeter
At my last CES two years ago, I spotted him at THE Show having lunch and schmoozing with fellow audiophiles and during our conversation he let spill that he had a new circuit design for a single ended amplifier. It uses a solid state power supply and TDA 2030 driver, a Sovtek 6A3 output tube, an inexpensive 300B variant and, of course, his inductors and transformers. Being the kindly soul that he is, he puts the circuit diagrams up on the web for all experimenters to freely use, asking only that they purchase the iron from him. The original circuit for this unit is at their website . He claims 21 watts output with less than 1 percent distortion from 18 Hz to 30 kHz, or about twice the output of the standard 300B SET amp. Now I know that it is anathema to some audiophiles to use solid state components in a tube amplifier circuit, but Jack's amplifiers have sounded so great over the years and he has such good ears, that I had to trust his judgment.
Up until now, I had been driving both my mid and tweeter horns with a single amplifier as they had had approximately the same sensitivity, but when I switched over to the RAAL tweeters, which sound superb and go out to the ultrasonic range without breakup, but are about 10 dB less sensitive, the mid horn had to be padded down so much that it affected its purity of sound. Thus, I needed a new set of three amps for the tweeters on my front three speakers. Unhappily, most SET amps are superb in the mid range, but due to transformer constraints have either a weak low or high frequency range and sometimes both. On discussing this with Jack, he mentioned that he had just designed a circuit that might just match my need for pure high frequency information.
It is a variant on the above EP-SEA2 design using parts, especially transformers that are chosen for their high frequency qualities, and an input circuit that includes several taps for different first order high pass frequency crossover points from 6000 to 9000 Hz. While the transformers can be purchased with copper, silver or his so-called partial silver stranded secondary (psss) and he suggested I use his solid silver output transformers, my bank book wouldn't allow it, so I settled for the psss units instead. Per my request, they were built as mirror images of each other using his recommended 6A3 output tubes rather than standard 300B's. They came with volume pots which I had asked for but ended up not needing as I needed the maximum input juice that my Marchand crossover would give me to match the RAAL driver with the mid-horn. The units were placed directly behind the drivers and connected with a short run of my favorite speaker cable hard-wired to the RAAL.
Before hooking it into the system one of the units was connected to my computer running the Windows MLS audio evaluation program which showed a low end frequency roll off of 6 dB almost exactly at the points determined by the internal crossover circuits various points, and the unit extended out to beyond 30 kHz, the maximum high end evaluation point of the computer's sound card running at 24-bits/96kHz.
As these were so-called one-offs, meaning the three were built to my specifications, with a circuit modified for maximizing high frequency output, I could not test the validity of the original circuits 18 Hz to 30 kHz ppecs, or the sound of the unit driving a full range speaker. Having Jack's DRD amp in my system and having had several of his previous units, I can attest to his circuits and transformers having masculine qualities in the woofer and even subwoofer range, with the classic 300B single ended mid-range. Whether the use of the solid state driver would affect the mid-range or not I'll have to leave to Jack's remarks at the end.
Happily, the chance I took in purchasing them "sound unheard" has turned out to be correct. Since the TAD 4002 drivers on the mid-horns go beyond 10 kHz., but have a 5 dB peak between 8000 and 9000 Hz, the optimum frequency response between them and the Electraprint amp was obtained using the Marchand XM-9 fourth order crossover with low pass on the mid-horn at 7000 Hz, and a combined fourth order high pass on the RAAL at 8000 Hz. the first order high pass on the Electraprint also at 8000 Hz. This did reverse the polarity of the driver which just meant reversing the speaker leads, but it flattened the high frequency curve of the speakers almost perfectly. Mated with the RAAL drivers, the highs go out to the stratosphere, clean crisp and alive. There is an added sense of space, especially with SACD and DVD-Audio recordings which have upper limits of 40-50,000 Hz or more.
While my old ears have a steep drop-off above 14000 Hz, and even brand new baby ears have a limit of about 20 kHz, one can sense frequencies much above that. This is due to the fact that waves of different ultra-high frequencies can beat against each other summing as waves in the hearing range. I was one of the subjects in medical school of an experiment 30 years ago (or was it 40?) that proved this. While the CD standard limited us to an upper limit of 20 kHz, DVD-Audio, SACD and Blu-ray allow at least double that, and speaker and electronics manufacturers are recognizing the advantage of super-tweeters and equipment that allow them to sing, capturing information lost in previous digital recording processes. Thus Jack's amps using the old 300B tube with parts that allow it to sing into the ultrasonic range are the way to go for me to get closer to live sound.
Anyway, Jack Eliano is one of those garage experimenters still found in some distant corners of high end audio who have taken the now 100 year old technology of tube amplification and 70 year old 300B circuit and elevated it to a new and wonderful level of audio reproduction. His original full bandwidth circuit amps or just the parts can be purchased through Jack at his website. And now a few words from Jack:
They, after the whipping, indicated a very good and accurate
article of what I do, having knowledge of my MO and putting up with me. Comments
such as "how did he know that?". I liked the part about the hetrodyne
effect of high freq mixing within the ear. Bruce's wife Nancy is an Audiologist
and we have talked about that one time, it is correct. I use the statement,
"The bandwidth to 20 kHz+ is essential due to the harmonic mixing of
musical instruments beyond hearing range and this is the result of what you can
hear." This was one of the many arguments of "lush mids", they
who say amps to 10 kHz sound better.
The amplifier is very similar to the SE A2 on our site except for the input and output arrangements. The input high pass filter consists of a selected group of capacitor values into a known fixed input impedance to form a 6 dB per octave low frequency cut. 3000, 5000 and 6000 Hz. this is a simple RC filter. This would provide absolutely no low frequency to appear at the output transformer which is built with a frequency response of 3 kHz to about 40 kHz, this output transformer is built with a partial silver wire secondary to offer increased detail due to silver's higher sensitivity to flux variations.
As for the article, it is great and thanks for all the attention you gave to the new topography of the circuit. its very hard to convey circuitry that is different, you helped on this. We had discussed indication of the different output transformers from the SE A2 amp but as it sits, it does not need this. I'm sure from all that you wrote, they who are interested will call me if interested. Again, thank you for the write up and attention its good to have friends like you.