This is my impression of the Light Speed Attenuator (LSA) in
my system that consist of the following equipment:
Amps: Two
Spectron Musician III MKII in mono block configuration with V-Cap Upgrade, Super-Effect
Bybee Purifiers upgraded rail and power fuses to Synergistic Research BLACK
Quantum Fuses (Outstanding fuse) driving 4 ohms.
The Spectron were chosen due to the
following capabilities: (What does the
limitation in peak voltage mean? To illustrate, let’s take example of a CD
player with typical output of 2.2V rms (i.e. peak 3V), and if you use XLR
balanced output then its peak voltage is 6 volts. Let’s for simplicity assume
that you are using passive preamp with gain set at this experiment to the unity
i.e. 1.0, and finally, let’s take typical amplifier which has usually gain of
26 dB or x20. Thus, you must expect your amplifier to have output peak voltage:
6V x 1.0 x 20 = 120V. This means that when listening to the same music with
most other amplifiers, particularly those without output transformers, the
signal would be "clipped". These amplifiers would be unable to
deliver the transient voltage to the speaker. The effect is that the music
loses some of its lifelike qualities i.e. signal is distorted and dynamics is
clearly compressed). The above example
represents situation when your preamplifier gain is unity i.e. with relatively
efficient speakers. When your speakers (or music) demand your preamplifier to
have gain more than 1.0, then even Spectron amplifiers might clip! Fortunately,
Musician III MK2 is capable of operating both in stereo and mono (fully
balanced) modes. While not necessarily an advantage for highly efficient
speakers as described above, less efficient loads will benefit from the fully
balanced operation that triples the power and doubles the headroom to + 240 volts as well as staggering 7000 watts
of peak power (and hold it for an extraordinary 500 msec) assuring that no
matter what the speaker load, the amplifier will deliver the full dynamics of
the original recording undistorted. Number of reviewers observed that Spectron
Monobloc’s sound creates noticeably deeper bass, effortless presentation and
powerful slam).
Usher BE-20 diamond sensitivity: 90 dB @ 1 watt
/ 1m at 4 ohms
VPI Prime with Dynavector xx-2 MKII cartridge
with the Symposium Prime Footer Damping Insert kit on Mapleshade 24 x 24 x 4
Finished Maple Platform with Audience Au24e Low Z Phono cables.
Whest 2017 version of the PS.30RDT SE with the
40 SE series wire loom and 40 SE input modules.
Crystal Cable Reference Diamond Interconnects.
Previous setups:
I was using the Sonic Euphoria Passive Line Controller (PLC),
the Sonic Euphoria PLC is a passive preamplifier using an autoformer attenuator.
The Purist Audio IRD LLC-P Preamplifier, also the Axiom passive with modifications
to the internal wiring with Mundorf sgw110wh wire, a mixture of Silver and 1%
Gold.
The closest of the above passives that came close to
achieving true non coloration of the sound and delivering only what was in the
recording was the modified Axiom passive.
I researched the Light Speed Attenuator and found
interesting comments from owners that ranged from outstanding to not a great
fit for my system. Due to prior passives
having plenty of gain for my system, I contacted George and made the
purchase. It arrived in Texas within the
two week period he stated he needed. He
provided outstanding technical support and even researched the problem I
noticed with integrating my Rel R528 SE subwoofer into the system. For some
reason using the Neutrik Speakon connector from my amp to the Rel caused issues
with the LSA, which to me sounded like an impedance matching issue. (I do not
miss the Rel with the LSA, there is plenty of deep articulate bass with my
Ushers alone, but will be searching for a fix).
LSA Power Supply:
Adding the LSA to my system was everything I have been
trying to achieve in my listening room.
I decided to power it with my HDPLEX 200W Linear Power Supply vs the
wart linear power supply due to the fact that it has a dedicated
XLR---5.5/2.1mm Connector Cable. Perfect
for the LSA and provides Top of the Line Hi-End Audio ELNA Capacitors, High
Quality 200W Silent R-Core Transformer provides clean energy, Separated Ground
for Each Output Rail, EMI/RFI Circuit to Prevent AC Grid Pollution, No Humming
or Buzz noise for 50Hz and Peak load, 100% Silent, High Quality Neutrik XLR
Connector for All Outputs, and Low ripple noise and void of high frequency
noise.
LSA Addition to
System Sound:
There are details in the midrange and treble that are just
more obvious now. The treble seems more extended, but there was absolutely no
change in tone from what is on the album.
Vocals are even more realistic, and everything has increased texture and
is more palpable. But the best thing of all is the increased speed of
transients. Everything has an immediacy to it. This even translates
to the very deep articulate bass. Kick drums have speed and an authority
that is impressive. The entire sound stage is one cohesive unit now in my
system.
There is a tremendous amount of fast energy. This is
consistent on all tracks played. The music has real life and
intensity. It is extremely quiet, musical, and detailed with a large
soundstage and is very well focused. I consider it an outstanding value for its
price range.
The best I've heard in my system to date. I perceive no
loss of dynamics at any volume. I can load my room adequately at around
9:30 or 10:00 on the dial. I have plenty of headroom and absolutely no
distortion at insane volumes. The bass has never been as good and the separation
and blackness are vastly improved. You feel the real image of the instrument’s
size and acoustic quality with all analogue recordings I have played to date.
Advantages of the
LSA:
With the LSA in my system, I have noticed that setting the
proper VTA on the fly with the VPI Prime on each record to optimize playback is
very easy and the changes are easily heard without the use of headphones for
precise imaging. From https://londonjazzcollector.wordpress.com/for-audiophiles/tonearm-vta-adjustment/
“Precise adjustment of the Vertical Tracking of your tonearm is one of the most
significant improvements you can make to your listening experience. It is not
as difficult as you may be thinking, and costs nothing. You have already paid
for your equipment, and though the turntable may have been set up “perfectly. In less than 15 minutes, the effect of
adjusting, refining the adjustment, and eventually locating the “sweet spot” in
VTA – just a turn of the adjuster, listen, turn a little more, listen, turn
again until you finally locate it –
completely transformed the performance of the system. The stereo sound stage
snapped into focus, the troubling bass lifted, harshness was replaced by
sweetness, an extraordinary and unexpected experience.”
Please understand that this is my experience with the
LSA with my equipment.
