bhaskar@fluke.UUCP (K.S. Bhaskar) (05/10/85)
My wife and I bought a Carver CD player a couple of days ago, and last night
we performed some A/B listening tests with Telarc's recording of Holst's Suite
No. 1 in E Flat and Suite No. 2 in F performed by The Cleveland Symphonic
Winds with Frederick Fennel. The rest of the equipment was a Pioneer PLL-800S
linear tracking turntable with PC-6MC cartridge, Phase Linear 3000
pre-amplifier, (heavily modified) Tapco CP 120 power amplifier and Nestorovic
Type 5 loudspeakers. Since the Carver does not have a variable output, the
procedure to switch between sources was via an intermediate null source,
during which the volume control was adjusted. The "Digital Time Lens" circuit
was also off during the test. The testing procedure was similar to another
test I reported on a few months ago with a neighbor's Sony CDP 102 player:
1. We synchronized the record and the CD as exactly as possible (to within
0.05 seconds, I estimate).
2. We determined the difference in the volume setting needed to make the CD
player and turntable sound equally loud. I adjusted the controls while my
wife commented on the relative loudness, during which time she did not know
which source was which. When it was my turn to play listener, I first
tried to discern if one was louder, and I could not. (The volume control
is detented, and the difference in setting was 4db.)
2. With the listener keeping his / her eyes closed, the other person would
start from an unknown source and switch sources (adjusting volumes on the
way) in response requests from the listener. The listener would listen
until satisfied as to which sounded better.
During quiet passages, it was always clear which source was the needle on
vinyl because of the noise level. At other times, even though I tried hard to
guess which was which based on noise, my guessing was correct only about 50%
of the time. But, the CD was definitely perceptibly quieter, as expected.
In this experiment as well as the last, my wife had trouble making up her mind
as to which she preferred. In the experiment with the Sony, she decided not
to pick one over the other. This time, she decided to pick one as sounding
better, and that proved to be the CD. In the previous experiment, I had
always been able to distinguish between the CD and the record, and I had felt
the record was better, so I began the experiment with a mental bias in favor
of the record, and twice picked the source that sounded better with, "That's
clearly the record." I was wrong both times. I was always able to
distinguish between the sources, however.
Subjectively, the record sounded harsher and the CD smoother -- in the earlier
experiment, I had found the vinyl to be smoother and more open. Both the
turntable and the Carver were very comparable with respect to imaging, and
with respect to open-ness of the sound, whereas I had felt the Sony sounded
muffled. We did not have time to experiment in detail with the "Digital Time
Lens" circuit. Informally, however, it appeared to improve both the bass as
well as the imaging!