Audio Research VT 100 Mk III Amplifier
Ask: $2500 + S&H + Paypal fees (2.9%) (includes new complete set of tubes - $400;
< 20 hours)
Pay Method: Paypal
Ship from: 45202
Cosmetic: 7/10; small nick on top left
side of faceplate. Please zoom in on pic.
Power output: 100 watts per channel continuous
from 20Hz to 20kHz. Approximate power at clipping is 120 watts.
THD: 1kHz total harmonic distortion (typically
.3% at 100 watts and below, .03% at 1 watt).
Power bandwidth: 12Hz to 60kHz (-3dB points at 1
Frequency response: 1hZ to 80khZ (-3dB at 1
Input sensitivity: 1.7V RMS (balanced or SE) for
rated output (24.3 dB gain balanced into 8 ohms)
Input impedance: 200k ohms balanced, 100 ohms
Output taps: 8 ohms, 4 ohms.
Overall negative feedback: 15dB
Slew rate: 8 volts/microsecond
Rise time: 4 microseconds
Hum & noise: less than 0.2mV RMS 103dB below
rated output (IHF weighted, input shorted)
Power supply energy: approximately 540 joules
Power requirements: 105-125 AC 60Hz (210-250 VAC
50 Hz); 650 watts at rated output, 800 watts maximum, 440 watts at idle
Tubes required: (4) matched pair 6550C; (4) 6H30
Weight: 66 lbs.; 83 lbs. shipping
19" (48.3 cm) W x 8.75" (22.2 cm) H x
19.5" (49.5 cm) D. Handles extend 1.5" (3.8 cm)
Reason for sale: Spring Audio Cleaning; Speaker change
and functional perfect
Manual and original
new tube set for resale (4 matched pairs) Sovtek 6550WE power output, (4)
Russian 6H30Pi Platinum Grade, Cryogenically Treated – Upscale Audio. Tubes are biased at 65mV and ready to go.
with Genesis APM-1 which was voiced with the VTM 200. Also used with the ACR LS25 Mk II preamp
which was a great combination. Wonderful depth and width soundstaging,
smooth yet inner detail transients revealed.
Any questions, let me know.
From Audio Research: Since the spring
of 1996 the VT100 established itself as the benchmark amplifier in its price
range. Accolades from the press and music lovers grew even louder with the 1998
introduction of the MKII because of its improved dynamic swing, more refined
performance, and ability to drive so many "difficult" loudspeakers
which normally could not be used with other vacuum-tube amplifiers. Well, the
VT100 in MKIII iteration will shake up the audio world once again and assure
that it remains the best-selling vacuum tube amplifier in the world.
advancements derived from the development of the remarkable VTM200 monoblocks
have been so large that we feel compelled to integrate many of them into the
VT100 through a MKIII update. This is a major step forward in sonics,
reliability, and ease of use.
the only changes are to the back panel where we have added two welcome
features. There is now a Balanced/Single-Ended switch, eliminating the need for
shorting links in the XLR balanced connectors when using single-ended RCA
cables. We have also incorporated a (dual in/out) 12V power on/off trigger for
remote or custom installation purposes. (The soft-start surge-control feature
of the VT100MKII power circuits is preserved.) Now you can link the VT100MKIII
to the LS25MKII for remote operation!
the circuitry of the VT100MKIII is derived from the VTM200. Like its more
powerful sibling, the MKIII's input stage utilizes direct-coupled JFETS for
ultra low noise, and is followed by a 6H30 driver/gain stage, capacitor coupled
to a 6H30 follower, driving two matched pairs of 6550C output tubes per
channel. The conservative 6H30 driver-follower circuit will help prolong the
life of the 6550Cs, and the 6H30 is rated to handle higher currents than the
previously used 6922, so it has lots of safety margin for even better
reliability. (The 6H30 twin triode is a Russian military tube in current
production, with an estimated service life of up to 10,000 hours.) There are
now four internal bias adjustments-up from the previous two- to allow more
accurate DC balance adjustments for the output tubes. The line fuse has been
increased to a 7 amp in 120V units (6.3 amp in high voltage units), allowing
the MKIII to handle musical dynamics with greater ease.
the VT100MKIII is a major sonic advance. As the original VT100 was greatly
improved upon by the MKII, the MKIII eclipses it again by the same margin.
Resolution and dynamics are startlingly better: suddenly you can pick out each
individual voice in a choir, you can hear the air gently modulated by a hundred
diaphragms singing in unison in a great cathedral. Small and large details
stand out in bolder relief, tightly focused, wonderfully holographic. Bass is
tighter and more dynamic. It sounds as though the power has been increased,
with a more effortless quality. The MKIII is easily recognized as having been
borne of the VTM200. Lastly, the single-ended RCA input is almost
indistinguishable sonically from the balanced-XLR input.