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Audio Research LS8 Mk.II
SOLD $2,500.00
JUN
2008

Introduced in 1997 as an affordable, yet reference-caliber
single-ended tube preamplifier, the original LS8 model has been
reengineered to Mark II status. This change takes advantage of some of
the same advancements introduced in our more recent and costly
preamplifiers, including the LS16, LS25 and Reference 2.
The new LS8 MKII is a pure Class-A circuit design with a large,
fully-regulated power supply and is hand-assembled to the same critical
standards as other Audio Research products. MKII component improvements
include new regulator FET devices, higher-quality resistors, new
Infinicap(r) coupling capacitors and our latest selected 6922 twin
triode vacuum tubes. Mechanically, the MKII incorporates new chassis
isolation feet, extensive internal chassis damping, and the proprietary
clear tube damping rings also used in the LS16, LS25 and Reference 2
models. The cumulative sonic gains are exciting: less smearing with
tighter focus of individual instruments, more lucid and natural-sounding
upper frequencies, better sorting out of complex orchestral programs,
improved dynamics and better bass control and impact. The overall sonic
presentation is smoother, more extended in range and more convincingly
authoritative.
External appearance and operational controls -- Gain, Input Select,
Power On / Off, and Mute / Operate -- are unchanged except for the
identifying MKII designation on the rear panel (which sports a removable
IEC-type power cord). A factory update to MKII status is available to
owners of original LS8 units. Suggested retail for the update is U.S.
$495, plus shipping to and from our factory. Updates must be
prescheduled through your authorized dealer or through the Audio
Research Customer Service Department.
We believe the new LS8 MKII actually outperforms the recently
discontinued LS15 when driving a power amplifier with single-ended
inputs. There is simply no other preamp in this price range which is
better able to provide such refined resolution, musicality and
naturalness in a simple-to-operate, easy-to-own package.
Specifications:
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Frequency response |
±.5dB, 0.5Hz to 100kHz -3dB
points 0.1Hz and 250kHz |
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Distortion (THD) |
Less then .01% at 2V RMS
output (typically .007% in midband) |
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Noise & hum |
20µV RMS IHF weighted noise
at main output with gain control at -60dB (100dB below 2V RMS
output) |
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Gain |
Main Output - 12.2dB
unbalanced |
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Tape output - 0dB |
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Input impedance |
50K ohms |
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Output impedance |
200 ohms main output.
Recommended load 60K ohms and 100pF (20K ohms minimum and 1000pF
maximum) |
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Output polarity |
Non-inverting |
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Maximum inputs |
3.5V maximum |
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Rated outputs |
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Power supplies |
Electronically-regulated
low and high voltage supplies. Line regulation better than .01% |
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Tube complement |
LS8: (4) 6922 |
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LS8 MKII: (4) 6922/E88CC
dual triode |
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Power requirements |
100-135VAC 60Hz (200-270VAC
50/60Hz) 30 watts maximum |
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Other |
Controls: Gain (64 step,
0.5dB per step for 40 steps), Input selector. Toggle switches:
Power On/Off, Mute/Operate. |
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Dimensions |
19" (48 cm) W x 5 1/4"
(13.4 cm) H (standard rack panel) x 10 1/4" (26 cm) D Handles
extend 1 1/2 " (3.8 cm)forward of front panel. Rear chassis
fitting extend 1/2" (1.3 cm). |
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Weight |
10 lbs. (4.5 kg) Net; 19
lbs. (8.6 kg) Shipping. |
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