LA-150 Mk. II Line Stage Pre-Amplifier
The original LA-150 was introduced in 2001 and has since become
one of the most sought after Preamps in Hi End Audio. This
version uses Russian Military tubes which many purist
audiophiles have been delighted with it’s overall sonic
signature. A typical example of this is Steve Hoffman of
“Digital Compact Classics”. The new version, dubbed LA-150 MII,
uses the same topology as the original design but both the Mu
Follower and Gain Stages now use the NOS 6350. This tube has
long been out of production but we have several thousand of
these tubes on hand. We have been using this tube for over 12
years in the LA-100 and our OTL's so it was only natural for us
to try it in our newest preamp. Needless to say, we have been
gratified with the success of this refinement. The Mark II
possesses all the best characteristics of the original while
having improved ambience and timbral recovery providing a more
musical presentation and satisfying spectral balance.
The output signal can still be taken from either the plate of
the Gain Stage or from the Mu Follower depending on system drive
requirements. Most systems will sound best with the “Plate
Follower” drive which is implemented with only a single vacuum
step in the signal path. The preamp is very dynamic, completely
free of glare or edginess, and boasts a 3 db down point at 5 and
100,000 cycles respectively. The 10,000 cycle square wave
response is essentially perfect and hum and noise are extremely
low. The bass performance of the preamp is very strong and solid
and the treble is open and airy with great extension
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All Tube Design including
separate tube regulated B+ supplies for each channel -
dual mono construction
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Separate regulated DC filament
supplies
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Four inputs including Tape In/Out -
dual output jacks
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All inputs - "Virtual Direct"
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MIT Caps, Cardas or Purist Wire and
Jacks, Holco Resistors
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Tape loop does not require buffer
stage for isolation
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Separated mute relays for each
channel; auto and manual mute
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Separate passive volume and balance
system with 'shunt to ground' input (not in signal path)
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Rear mounted selector switch for
short signal path and
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Multiple contacts in signal path
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Adjustable battery bias for gain
stage
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"Tri-flex" elastomer suspension for
signal board
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State-of-the-art "Sound Coat" and
"Ear Isodamp Vibration" isolation materials
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Remote Included
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Warranty Parts & Labor, 3 yr
|
Specifications |
|
Input Impedance |
15,000 Ohms |
|
Output Impedance |
Selectable: 400 Ohms & 1200 Ohms |
|
Distortion |
< 0.1% @ 5 volts into 5,000 Ohms |
Gain
Bandwidth |
0 to 11dB, Selectable
100 kHz |
|
Tube Complement |
2 - 6EM7
4 - 6350
2 - O-A2'a (or Zerner Diodes) |
|
Weight |
23 lbs. |
|
Power Consumption |
< 50 watts |
|
Power Storage |
150 Joules |
|
Dimensions |
Width - 17.5 inches
Height - 6.0 inches
Depth - 12.5 inches |
Channel Separation
Frequency Response |
> 80dB
10 Hz - 100 kHz (+/- 1 dB)
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