Vinnie Rossi’s New Flagship Design

L2 Signature Preamplifier

PREAMPLIFIER

Overview

Likely the world’s first example of extreme performance derived from absolute circuit reductionism, the L2 Signature Preamplifier brings an unmatched listening experience. We configure only one pair of the finest sounding 4-pin, directly heated triodes (DHT) in a dual-mono, class-A, grounded-grid topology with zero feedback. Absolutely no compromises in bandwidth, phase, speed and directness, and no distracting effects of driver tubes, coupling caps or output transformers equates to reproduction of music with intense spaciousness, harmonic sophistication, liquidity and detail that surpasses small triodes and transistors alike.

Vinnie Rossi also included various degrees of flexibility into his statement design. Numerous DHT tube families are compatible with the flick of a switch, and the tubes can be easily bypassed and substituted with a purist JFET buffer stage for a change of mood or to assess the precise contributions of a particular pair of tubes against a bypass. Perhaps most enticing are the optional L2 Dac and Phonostage add-on modules, each fed from independent, super-regulated power feeds. If you crave the incomparable sound of big, direct-heated triodes without limitations, we invite you to experience the incredible sense of realism and effortless musical connection that the L2 Signature Preamplifier delivers.

Each unit is meticulously hand-built and tested by Vinnie Rossi himself. Its no-compromise construction with integral resonance control and use of the highest-quality components assure that the listener will enjoy superior performance for many years.

Design

STANDARD FINISHES

Features

  1. Vinnie Rossi’s latest Class-A, ultra wide bandwidth directly heated triode (DHT) preamplifier design, compatible with: 2A3, 45, 300B, PX4, 101D, 205D, and SV811 DHT families with one-switch filament voltage selection.
  2. Dual shielded power supplies with in-rush current limiting.
  3. Dual-mono layout using multiple patented Belleson super regulators for ultra-quiet linear voltage regulation of the L&R triode B+, L&R triode filaments, and power to the (optional) L2 DAC and L2 Phonostage modules.
  4. Discrete, 64-step resistor ladder volume control using Pickering England silent signal relays.
  5. True active balanced (XLR) and single-ended (RCA) inputs and outputs.
  6. Dual 12V Trigger output jacks with on/off control switch on front panel.
  7. Internal, “DHT bypass mode” switches (Replaces DHT stage with a Class A JFET stage).
  8. Internal front panel display & LED brightness controls.
  9. Yamamoto solid Teflon UX-4 tube sockets.
  10. Solid, precision CNC machined aluminum chassis and “bank vault,” ball bearing control knobs.
  11. Solid, precision CNC machined aluminum ‘L2 isolation Base’ with Stillpoints ULTRA MINI feet.
  12. Mesh tube covers for added noise shielding and tube protection, with matching mesh ventilation on top panel.
  13. Included tubes: EH300B Gold-Grid (matched pair).
  14. Full-function aluminum remote control handset.
  15. Designed and manufactured in the USA.
  16. 10-year warranty.
  17. Includes custom, military-grade hard travel case.

L2 SPECIFICATIONS

Frequency Response (with stock EH300B tubes):2Hz – 500kHz (+/- 0.5dB)
0.5Hz – 950kHz (+/- 3dB)
Output Impedance (SE and BAL):< 100 ohms
Input Impedance (SE and BAL): Approx. 10K ohm
Voltage Gain:8 dB (with stock EH300B tubes)
0dB (DHT Bypass Mode / Unity gain JFET buffer only)
SNR (with stock EH300B tubes):
SNR (DHT Bypass Mode):
-120dB (A-Weighted), SE IN/OUT
-140dB (A-Weighted), SE IN/OUT
12Vdc Trigger Outputs:12V (+/- 0.1V), 200mA max (each) with on/off switch on front panel
THD+N (with stock EH300B tubes):
THD+N (DHT Bypass Mode):
Less than 0.5% (unweighted), SE IN/OUT
Less than 0.0006% (unweighted), SE IN/OUT
AC Input:Factory configured for 110-120Vac  -or-  220-240Vac (50/60Hz)
Volume Control:

Balance Control:

64 steps (approx. 1dB per step) from -∞ to +8dB

24 steps from L to R (approx. 1db per step)

Power Consumption (with stock
EH300B Gold Grid  tubes, L2 Dac and L2 Phonostage installed):
Approx. 65W
Protections:– Fused AC input
– MOV (AC input surge protection)
– Output short circuit protection
Dimensions (With mesh tube covers and isolation base installed):Approx. 17.25″ wide x 14.5″ deep x 8.75″ tall (438mm x 368mm x 222mm)
Weight:
Shipping Weight:
38 lbs (17.2 kg)
62 lbs (28 kg) including travel case
OPTIONAL

L2 DAC

The L2 DAC is our latest, statement-level d-a converter module that allows music to flow in an effortless manner that mirrors true analog playback with its highly resolving and dynamic, yet non-fatiguing sound signature. No matter if you are playing PCM files from 16-bit/44.1kHz to 32-bit/768kHz or DSD files from DSD64 to DSD512, you will become captivated listening with Vinnie Rossi’s approach to digital playback.
  • Bit-perfect playback at sampling rates up to PCM 768kHz (16, 24, or 32 bit compatible), as well up to DSD512. Sample rates are viewable from front panel display.
  • Dual-mono design, with one flagship AKM AK44497EQ d/a chip per channel.
  • Fully discrete, pure Class-A JFET analog outputs stage design with cascode constant-current source biasing (no opamps).
  • On-board FPGA buffer and femto-reclocking circuitry negates effects of jitter. Isolated input stages.
  • ‘NOS’ (non-oversampling) filter mode with digital filter bypass, as well as a Minimal Phase digital filter mode (selected via the “FILTER” button on the L2 Remote).
  • Absolute polarity ‘normal’ / Absolute polarity ‘inverted’ modes (selected via the “PHASE” button on the L2 Remote).
  • Belleson Super-regulated voltage feed to numerous ultra-low noise, linear voltage regulators used throughout (for both digital and analog sections).
  • “Silent” mute ‘reed relays’ (*barely* an audible click from the board when changing tracks of a different sample rate).
  • Inputs: 1 USB, 1 Coax (75-ohm BNC, with included RCA adapter) and 1 TOSLINK (optical).
  • Connect up to three devices and switch between them via L2 front panel or the remote handset.

 

Output Voltage:2.0V rms
Output Impedance:< 100 ohms
SNR:> 115dB
Playback Bit Rates Accepted (PCM):16, 24, 32
PCM PlaybackWindows PC: 44.1, 48, 88.2, 96, 176, 192, 352, 384, 705, and 768kHz – driver included. Mac OSX: 44.1, 48, 88.2, 96, 176, 192, 352, 384, 705, and 768kHz – no driver required. Sonore: 44.1, 48, 88.2, 96, 176, 192, 352, 384, 705, and 768kHz
DSD PlaybackWindows PC: DSD64, DSD128, DSD256, and DSD512 (both Native mode, and DoP) – driver included. Mac OSX: DSD64, DSD128, DSD256 (DoP) – no driver required. Sonore: DSD64, DSD128, DSD256, and DSD512 (both Native mode, and DoP
OPTIONAL

L2 Phono

L2 Phono is our new, statement-level phonostage that we designed in collaboration with Brian Lowe of Belleson (patent owner of the Belleson super-regulators used throughout our L2 products). It provides a highly resolving, dynamic, and entirely natural sound signature that will bring you a whole new level of enjoyment from your LP collection.

L2 Phonostage Features

  • Inputs: 1 set of Moving Magnet (MM), 2 sets of Moving Coil (MC)
  • Built-in, on the fly MC remote adjustable cartridge loading (10 – 1000 ohms). Cartridge load setting viewable from L2 front panel display
  • Adjustable gain jumpers for MM and MC inputs
  • Belleson Super-Regulated split-supply voltage rails
  • Four low-noise and low distortion gain stages. Each stage has a nominal gain of 20dB, resulting in higher bandwidth per stage and lower phase shift across the audio band
  • Low output impedance design
  • DC coupled from input to output (no dc blocking capacitors added in series to the signal path)
  • DC Servo keeps output offset negligible
  • Design optimization for lowest value thin-film resistors, resulting in the least possible noise
  • High accuracy resistors and capacitors used throughout
  • 4-layer PCB with separate ground planes for analog and digital (control circuitry)
  • Cardas Audio input jacks
  • Connect up to three tone arms and switch between them via L2 front panel or the remote handset
MM Gain Settings:40dB, 46dB
MC Gain Settings:60dB, 66dB, 72dB
Output Impedance:< 100 ohms
Noise (3Vrms output, 1kHz):> 90dBV
THD (3Vrms output, 1kHz):< 0.002%
RIAA Accuracy (20 – 20kHz):+/- 0.5dB
Output DC Offset Voltage:< 2mV (servo controlled)