Technical Articles and Editorials
- Written by John E. Johnson, Jr.
- Published on 12 August 2008
Part 1: Introduction
When attending CES and Rocky Mountain Audio Fest over the past couple of years, I noticed that turntables are starting to be the majority of sources for exhibit rooms. We all have heard about the vinyl renaissance, but I just did not realize how strong it is. I mean, LPs are being played everywhere at hi-fi shows.
The feeling is that LPs still sound better than CDs, even SACDs, so I decided to run some experiments comparing the sound of LPs that were sourced from analog recordings, and CDs/SACDs also made from those analog tapes.
It is taking me more time than I realized it would, with some issues along the way that need to be solved, so rather than wait until it was all done, I thought I would share with you the results as I gather them, in a running commentary. This will also allow our readers to ask questions along the way, even suggest some tests that you might want me to run while I have all the test equipment connected.
Click HERE to go to Parts 6-9 (Part 6: In the Groove, Part 7: THD+N Test Results, Part 8: Phono Preamplifiers, and Part 9: A Few Bits About DACs).
I contacted two companies (to begin with) that I greatly respect: McIntosh and Bryston. I asked McIntosh if they would be willing to send me their new MT10 turntable, and Bryston if they would send me another BP-26 preamplifier that I reviewed in the Fall of 2007. Both agreed with enthusiasm, knowing that I would be doing some in depth testing with my Audio Precision that probablly has not been done before. Since the BP-26 could have either a DAC or phono stage (phono preamplifier) installed, but not both, we decided to have the separate BP-1.5 phono stage to accompany the BP-26. That way, I could decode a CD bitstream in the BP-26, but then have the BP-1.5 handle the RIAA equalization from the phono cartridge, and all preamplification circuits would still be Bryston. A second reason I asked Bryston to participate, was the fact that my tests of the BP-26 revealed it to have astonishingly low distortion, and I obviously wanted the Audio Precision to be measuring distortion coming from the analog recording vs. the digital recording, rather than from the preamplifier.
Both the BP-26 and BP-1.5 are powered by the same power supply, which eliminates one more variable. Here is a photo of the trio installed on a shelf in the lab. As always, just click on the photos to see larger versions. The power supply is on the bottom, the preamp controller is in the middle, and the phono stage is on top.
The McIntosh MT10 is a new product from the big MC. They don't seem to have bothered trying to promote it much, because McIntosh fans have been snapping them up like crazy anyway. Below is shown a photo of the MT10 installed on a shelf in the lab.
The MT10 comes with the tonearm and a cartridge already installed. I needed only to add the counterbalance weight and the anti-skating weight (to be described below), plop (gently) the turntable on the spindle, and it was time to boogey.