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Pure Vinyl News
| April 16, 2008 |
Pure Vinyl 2.2 released!
| March 5, 2008 |
Pure Vinyl 2.1 released!
And... stay tuned for more information about the Seta preamplifier. Revised specs and features. The wait will be more than worth it...
| January 23, 2008 |
Pure Vinyl 2.03 is released.
| January 4, 2008 |
Pure Vinyl 2.02 is released (a free, compatibility update for Mac OS X 10.5 "Leopard"). Now includes a free* activation code for Channel D's AudioLeak 2.0 audio file inspector / loudness analyzer / metering software (included with Pure Vinyl 2.0.2 download)!
*with the purchase of a Pure Vinyl activation code
| December 11, 2007 |
Seta preamplifier performance measurements page updated.
| December 7, 2007 |
We've finally received a shipment of the first production run of Seta preamplifier circuit boards.
The bandwidth (-3 dB) isn't 1 MHz. Nope. Input to output, it's greater than 1 MHz.
A lot greater, in fact (how much, exactly? We'll save that information for later).
We're extremely pleased, and have made extensive measurements (with all potentially bandwidth-reducing input and output protection circuitry in place, of course), that we'll be posting very soon, in advance of our shipping of this ground-breaking phonograph preamplifier. At that time, the specifications, compared to the original October 12 news release posted below, will be (favorably) revised (corresponding with the results from these tests).
In addition, we have a couple of important surprise announcements planned for the time of the shipment of the Seta.
Click on the image above to see technical measurements of the Seta preamplifier.
Why be concerned with reproducing a bandwidth exceeding the conventional 20 kHz audio range? Does audio reproduction involve megahertz frequency signals?
The short answer is: No. But, phonograph music reproduction is slightly more complicated.
The long(er) answer is that the signals from a vinyl record are pre-emphasized: in other words, the high frequencies are boosted by as much as 20 dB (10 times). This stresses preamplifiers to a higher degree, in the frequency range where preserving signal integrity is at its most difficult. Unfortunately, distortion in the upper octaves can cause intermodulation distortion that also affects the critical midrange, creating what's best described as a subtle "haze" that obscures vital musical details. We have confirmed this during several years spent in developing this product, involving extensive listening evaluations beginning with rudimentary but surprisingly capable "jelly bean" op-amp designs, then finally evolving into a hybrid topology culminating in the Seta preamplifier design, with a bandwidth of well over 1 MHz, even at high gain settings.
What's more, the frequency response of vinyl is much wider than the "20 Hz to 20 kHz" response of human hearing. Recordings that push the limits of the upper frequency range of vinyl bandwidth are more common than you may realize. This is especially true of well-recorded "audiophile" recordings, for which extra care has been taken in the mastering process. Here is an example of an analysis of the frequency range of such an audiophile remastering, focusing on a recording with high-frequency percussion sounds. In that example, the energy above 20 kHz will prove troublesome for narrow-bandwidth preamplifiers, intermodulation distortion producing a noticeable, hard midrange "splat" or crunching sound, distracting the listener from the reproduction of the crystalline bell's sound...
Click above image for vinyl frequency response analysis example.
It doesn't matter whether it's a strictly linear gain stage like the Seta, to be used with our Pure Vinyl software; or a linear gain stage followed by standard passive RIAA phonograph equalization (as in many conventional - and high end - phonograph preamplifiers). The same principles (and limitations) apply.
In other words: a preamplifier, such as the Seta, that's capable of reproducing signals with a bandwidth well over 100 times greater than "typical" audio signals, insures that the preamplifier, when working in the audio frequency range, is operating with significantly reduced strain and distortion - the equivalent of a "straight wire with gain" - which is the ultimate goal of all "audio" amplifiers.
The dramatic result: Seta unmasks previously hidden details from your treasured vinyl records.
(Above) Seta™ Rear Connection Panel
| October 12, 2007 |
Demonstrated at Rocky Mountain Audio Fest: Seta Moving Magnet / Moving Coil Cartridge Balanced Input / Output Preamplifier (Shipping soon)
Below: Photos of the Pure Vinyl demonstration room at the recent 2007 international Rocky Mountain Audio Fest, Denver, Colorado.
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Demonstration System:
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Thanks to all of our Pure Vinyl users who made the trip to Colorado and dropped by to say hello, and listen to our new Seta phonograph preamplifier; and all of our new friends who took the time to have a seat and listen!
Read what Adam Goldfine of Positive Feedback said about the Seta in their Rocky Mountain Audio Fest show report (scroll to end of article): http://www.positive-feedback.com/Issue33/rmaf_ag.htm
Read what Marja and Henk of sixmoons audio said about the Seta in their Rocky Mountain Audio Fest show report (scroll about 1/3 of the way down, and includes a photo of the inside of the Seta we used for all vinyl playback at RMAF): http://sixmoons.com/industryfeatures/denver07m+h/denver_6.html
| October 5, 2007 |
Technical "white paper" on software RIAA correction presented by Channel D's Director of Engineering at the 123rd Audio Engineering Society Convention in New York City
(Paper abstract below):
P4-6 Filter Reconstruction and Program Material Characteristics
Mitigating Word Length Loss in Digital Signal Processing-Based
Compensation Curves Used for Playback of Analog Recordings
Renewed consumer interest in pre-digital recordings, such as vinyl
records, has spurred efforts to implement playback emphasis compensation
in the digital domain. This facilitates realizing tighter design
objectives with less effort than required with practical analog
circuitry. A common assumption regarding a drawback to this approach,
namely bass resolution loss (word length truncation) of up to
approximately seven bits during digital de-emphasis of recorded
program material, ignores the reconstructive properties of compensation
filtering and the characteristics of typical program material.
An analysis of the problem is presented, as well as examples showing
a typical resolution loss of zero to one bits. The worst case
resolution loss, which is unlikely to be encountered with music,
is approximately three bits.
Convention Paper 7185
Note: official reprints of this paper will be provided for the asking at the 2007 Rocky Mountain Audio Fest. Additional copies of the paper will be made available for download pending release obtained from AES in mid - 2008, per their standard Convention Paper procedures.
| August 13, 2007 |
Coming Soon:
(Above) Vestitino di Seta™ Rear Connection Panel (Right Channel shown, with Enclosure Top Removed)
| August 10, 2007 |
| October 20, 2006 |
Photos below: playing and listening to music in the Pure Vinyl demonstration room at the 2006 international Rocky Mountain Audio Fest, Denver, Colorado
Pure Vinyl mentioned in the audiophile press:
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