Tube Preamp Reviews

Lamm Industries LL1 Signature line preamplifier Specifications

Sidebar 1: Specifications

Description: Dual-mono, four-chassis line stage with outboard power supplies. Tube complement: four 6N30P-DR (each preamplifier), two 6X4 (each power supply). Frequency response: 20Hz–20kHz, –0.1dB; 5Hz–140kHz, –3dB. Maximum voltage gain: 7.43x, 17.4dB, ±2%. Additional attenuation: 3.98x, 12dB, ±0.17dB. Slew rate: 47V/µs. Rise time: 0.61µs. Total harmonic distortion: <0.03% at 1V RMS into 41k ohms); <1% at 50V RMS into 41k ohms. IM distortion: <0.09% at 1V RMS into 41k ohms; <1% at 10V RMS into 41k ohms. Input sensitivity: 135mV RMS, ±2%. Input impedance: typically 16.5k ohms. Output impedance: 200 ohms. Rated output voltage: 1V RMS. Signal/noise: >87dB, wideband, unweighted; >90dB, 22Hz–22kHz, unweighted; >97dB, A-weighted.
Dimensions: 19" (485mm) W by 4.5" (115mm) H by 15.25" (390mm) D (same, preamplifier and power supply). Weights: preamplifier chassis, each 35.6 lbs (16.2kg); power supply chassis, each 21.2 lbs (9.6kg).
Finish: Black-anodized aluminum.
Serial numbers of units reviewed: 110031, 110032.
Price: $42,790. Approximate number of dealers: 17.
Manufacturer: Lamm Industries Inc., 2513 E. 21st Street, Brooklyn, NY 11235. Tel: (718) 368-0181. Fax: (718) 368-0140. Web: www.lammindustries.com.

COMPANY INFO
Lamm Industries Inc.
2513 E. 21st Street
Brooklyn, NY 11235
(718) 368-0181
www.lammindustries.com
ARTICLE CONTENTS

COMMENTS
otaku's picture
Submitted by otaku on August 1, 2014 - 10:18am

I guess I could listen just to mono LP's and save $21,395.

markotto's picture
Submitted by markotto on August 4, 2014 - 5:09pm

I certainly hope it is "the best possible sound from a line-stage preamplifier".

Oldsport's picture
Submitted by Oldsport on August 18, 2014 - 8:18am

Hi John, just a thought on a possible noise source (and this may be opening a new audiophile can of worms). Do you have any compact fluorescent lights (CFLs) in your testing area? Those buggers emit RF; they may also dirty up the A/C as well, I don't know. Just hold a cheap AM radio next to one and have a listen. I won't have any in my listening room--they definitely degrade the sound. In fact, I try to have all CFLs turned off on the entire floor that my listening room is on, when I'm using it. Regards!

John Atkinson's picture
Submitted by John Atkinson on August 18, 2014 - 11:48am
Oldsport wrote:
Do you have any compact fluorescent lights (CFLs) in your testing area? Those buggers emit RF; they may also dirty up the A/C as well

Yes I do! I don't have the Lamm available anymore but I will try replacing the CFL with a normal light bulb and see if I can change the measured noise level with a different preamp.

A subsequent discussion with Vladimmir Lamm revealed that he measures wideband signal/noise ratio with a 110kHz bandwidth whereas I use 500kHz. That would explain the differences in our measured results, especially as I have the CFL in my test lab.

John Atkinson
Editor, Stereophile

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