a topology that brings out the most natural sound performance


The LP2.1 is a dual-mono vacuum tube phono preamplifier with two electrically and mechanically separated channels. It features a topology that brings out the most natural sound performance in the audio path, as well as graceful and sophisticated design.

design elements


Model LP2.1 is the next generation of the original LP2 — the first in the line of LAMM phono preamplifiers.

The LP2.1 features the following upgrades and modifications in comparison to the LP2:

  • introduction of many technical solutions that had been implemented in the LP1 Signature (just like the ML2.2 single-ended power amplifier derived many of its technical solutions from the ML3 Signature power amplifier);
  • introduction of the new tubes: 6C3P and 6C45P-E (same tubes that used in the LP1 Signature phono preamplifier), and corresponding adjustments in the circuitry;
  • significantly reduced output impedance;
  • new parts that had been developed by various manufacturers since the introduction of the LP2;
  • new pc-board material
  • super low noise power transformer

The preamplifier operates in a pure class A mode from input to output.  High-current drive capability, in combination with unique single-ended class A circuitry, enable the preamplifier to drive any cable and any reasonable real world load, while maintaining its practically inaudible sonic signature.  When connected to the appropriate type of electronics, and especially LAMM amplifiers and preamplifiers, it assures the extraordinary transparency of perceived sound and recreation of a three dimensional soundstage in the home, recording studio, etc. without boundaries and limitations. 

components


All amplification stages utilize high transconductance very low noise high-current vacuum triodes.  No loop feedback is employed.  

The LP2.1 features a very accurate passive RIAA EQ network.  The preamplifier’s audibly neutral power supply features a full-wave vacuum rectifier which, together with a choke-containing filter, helps reduce the hum and buzz to almost negligible levels and, in the end, ensures the verity of dynamic range without coloration.  Solid-state analog voltage regulator is used as a heater supply. Other features include two sets of inputs for each channel and gain/selector switches for MM and MC cartridges. 

A unique electronic protection circuitry mutes the outputs until the LP2.1 has stabilized upon being turned on; it also automatically mutes the preamplifier in case the AC line voltage drops or is interrupted, as well as at the turn-off of the unit.   

Each preamplifier is carefully crafted with the hand selected components of the highest quality, some of which include military graded low noise DALE metal film resistors; 1% tolerance RCD wire-wound resistors; ELECTROCUBE and VISHAY/ROEDERSTEIN film capacitors; high frequency switching grade CORNELL DUBILIER electrolytic capacitors; FISCHER “Camac” connectors; specially selected military-graded low-noise long-life vacuum tubes; and a custom-designed super low noise power transformer.   

The LP2.1 is especially effective in large systems with speakers of reference quality that make it possible to recreate the unique qualities of LPs.  The LP2.1 is designed to be used as part of the truly hi-end audio system and is capable of reproducing the studio- or life-recorded musical event with reality approaching that of the concert hall.  It is also designed for use in the recording studios as a reference preamplifier for the purpose of controlling the recording process itself and the quality of LPs. 

The LP2.1 is available in two versions: standard and deluxe.  In the deluxe version, the power supply stores more energy, all film capacitors in signal path are bypassed by polystyrene capacitors of the highest available quality, and a custom-designed massive damping panel significantly reduces all types of mechanical vibrations which, in turn, leads to a slightly more extended, coherent and natural bass reproduction.  

The LP2.1 works on all world AC line voltages. Download the LP2.1 booklet here

audio critic reviews coming soon


Measurement


The following data represents the LP2.1 as performed by an independent party:
Mr. Bascom H. King of BHK Laboratory (bhk@rain.org).

Rated Output Voltage
F = 1KHz:
MM input to output: 0.125 Volts RMS.
MC input to output: 0.125 Volts RMS.
Voltage Gain*, **
F = 1KHz:
MM input to output: typically 100 or 40dB.
MC input to output: typically 1000 or 60dB.
RIAA Accuracy*
From 20 Hz – 20 KHz: better than + 0.0 dB/-0.5 dB, typically.
Phono Overload
F = 1KHz:
Phono MM: 225 + 15 millivolts RMS.
Phono MC: 22.5 + 1.5 millivolts RMS.
Total Harmonic Distortion* from 20 Hz – 20 KHz; RIAA de-emphasis
Vout=0.25 Volts RMS:
MM input to output: no more than 0.1%.
MC input to output: no more than 0.16%.
Vout=10 Volts RMS:
MM input to output: no more than 1%.
MC input to output: no more than 1%.
Inputs
Unbalanced: gold plated single-ended RCA connectors.
Input Sensitivity
Vout=0.125 Volts RMS, F = 1KHz:
MM input: typically 1.25 millivolts RMS.
MC input: typically 1.25 millivolts RMS.
Input Impedance
F = 1KHz:
MM input: 47 KOhms shunted by 200 pF.
MC input: 400 Ohms.
Outputs
Unbalanced: gold plated single-ended RCA connectors.
Corrected Impedance
Corrected output impedance: typically 2.3 KOhms.
Noise
Signal-to-noise ratio, below 1 Volts RMS output, A weighted:
MM input to output (shorted input): typically 88dB.
MC input to output (shorted input): typically 86.5dB.
MM input to output, with IHF dummy load in MM position: typically 84dB
MC input to output, with IHF dummy load in MC position: typically 82.5dB
Absolute Phase
MM input to output; non-inverting.
MC input to output; non-inverting.
Operating Temperature
-4 to +104 degrees Fahrenheit (-20 to +40 degrees Celsius) ambient.
Power Supply
Each LP1 contains two identical external power supplies – one for each channel. Therefore, all further information regarding power supply is shown for ONE power supply, unless otherwise indicated).
Nominal line voltage: 100-240 Volts, 50/60Hz.  
Input voltage range: ±10%.
One power transformer; two filter chokes; one full-wave
vacuum rectifier; one solid-state analog non-switching voltage regulator.  
AC voltage intensively filtered by special RFI power line filter.
Power Supply Energy Storage
Regular version: approximately 125 Joules.
Deluxe version: approximately 150 Joules.
Front Panel Controls
LED control.
Rear Panel Connectors & Controls: Preamplifier
EC320 power inlet (3 lug).
EARTHING post.
PHONO grounding post.
Two pairs of INPUT CONNECTORS RCA for PHONO inputs.
Two SELECTOR/GAIN switches.
One pair of OUTPUT CONNECTORS RCA.
Features
Pure class A vacuum tube design. All stages are single-ended.
No loop feedback is employed. High-current drive capability, in combination with unique single-ended class A circuitry, guarantee the preamplifier to drive any cable and any reasonable real world load, while maintaining its practically inaudible sonic signature.
Tremendous reserves of headroom and output drive capability are engineered into the LP2.1.
Specially designed damping panel installed in the LP2.1’s deluxe version effectively isolates all sensitive electronic components from any induced resonances.
Absolutely outstanding signal-to-noise ratio makes the LP2.1 one of the quietest phono preamps available on the market.
This design is unique to LAMM INDUSTRIES, INC.
AC voltage selector:
100/120/220/230/240 Volts, internally switchable.
Safety:
Unique electronic protection circuit enables muting of the outputs until the preamplifier is stabilized after a turn-on, as well as functioning of the preamplifier in a “muting” mode during operation, and automatic switching to muting in case the AC line drops or is interrupted.

AC voltage fuses: 2 Amps slo-blo for 100/120 Volts. 1 Amp slo-blo for 220/230/240 Volts.

General
Power Consumption: Typically 75 Watts.
 Burn-in Time at Factory: Minimum 72 hours.
Recommended Burn-in Time in End-user’s System: Minimum 100 hours.
Warm-up time: Minimum 45 minutes.
Unit dimensions: 4.5 inches high x 19 inches wide x 13.875 deep + 1.375 inches for front handles.
Crate dimensions: 23″ x 19″ x 10″ (58.42cm x 48.26cm x 25.4cm).
Unit weight regular version: 22 Lbs (10 Kg).
Unit weight deluxe version: 41.5 Lbs (18.84 Kg).
Shipping weight regualr version: 43.1 Lbs (19.57 Kg).
Shipping weight deluxe version: 62.6 Lbs (28.42 Kg).
Tube Complement:
V101 -6C3P / 6C3П, left channel, first amplification stage;
V102 – 6C3P / 6C3П, right channel, first amplification stage;
V103 – 6C45P-E / 6C45П-E (original), left channel, second amplification stage;
V104 – 6C45P-E / 6C45П-E (original), right channel, second amplification stage;
V105 – 6X4, full wave voltage rectifier.

* All measurements were taken with the 41 KOhm load connected to the preamplifier’s output.
**  Voltage gain and Input sensitivity may vary within a -15% range of the specified value, as it is dependant upon the tube selection; however, the amplification variance between the left and right channels does not exceed + 2%.