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L1 Dual Monaural Line Preamplifier

  1. General
  2. Features
  3. Options
  4. Specifications
  5. Downloads

The uttermost quality of a preamplifier is its transparency. The source is selected and the volume is applied, however the original audio characteristics and signal dynamics are fully retained. The L1, a dual monaural analog line level preamplifier, was developed using this approach. It is a pure class A, ultra low noise, high bandwidth, fully balanced transistor based design. It provides the shortest path between input and output, maintaining the highest speed, transparency and musicality, allowing the L1 to become a truly exceptional preamplifier.

Modularity

Three L1 configurations are available:

  • Monaural operation, with 8 inputs
  • Stereo operation, with 8 inputs for each channel
  • Monaural operation, with 16 inputs
Volume control

For each channel two R-2R ladder network in balanced mode control the volume. Tight tolerances high-grade metal film resistors as well as fast switching, distortion-free analog switches are used to adjust precisely the listening level. Each ladder has the following features:

  • 20bits R-2R ladder network
  • 118dB volume range in 0.5dB steps, from -100dB to +18dB
Analog signal path

Extreme care has been given to the timing of the audio conversion. The clocking section of the C1 is based on two ultra low jitter digitally controlled VCXOs to support synchronously every available audio sampling rates.

When equipped with the optional synchronization board, the C1 can be used with external clock generators or it can transmit the D1 SACD/CD drive a synchronization clock in order to slave it.

D/A conversion

The digital to analog converter boards are full dual mono with one board per channel. A dedicated set of regulated power supplies has been built for each channel in order to keep the channel separation at its maximum. Each channel is using four R-2R converter in a balanced design to create directly from the D/A conversion process an analog balanced signal.

Volume control

An integrated volume control is embedded into the C1, which can be turned off in case an external analog preamplifier is used. It has been done with a mix of analog and digital steps to ensure the best possible resolution at all listening levels. Coarse steps are done with relay-driven resistor-based dividers, while the fine steps are done into the DSP engine in floating point.

Analog stages

All analog stages inside the C1 are built only with discrete components, no operational amplifier have been used into these sections. This deliberate choice warranties the shortest path for the audio signal and allows the use of custom-made building blocks. All analog stages have the following features:

  • no use of global negative feedback
  • operating mode in pure class A
  • fully symetrical design

No capacitors have been used in the signal path to ensure the maximum transparency.

Options boards

L1 Enclosure

 L1 enclosure

L1 enclosure

The addition of a second L1 enclosure transforms the L1 into a True Monaural preamplification system. The power supplies inside each enclosure are devoted to a single channel, further enhancing the noise performances of the system. The units are
controlled simultaneously. More units can be linked together in a multichannel system.

PRE

L1 Preamp board

Monaural analog preamplifier board

In a True Monaural system (with two enclosures), each enclosure is able to receive an extra
preamplifier board. This turns the L1 into a True Monaural Extended system, providing
the preamplifi er with twice as many inputs, ideal for larger systems.

External power supply

X1

x1

 

X1 external power supply

Improves the overall L1 performances by adding an external power supply unit.

Same unit dimensions as the L1

Analog inputs

Inputs type

4x Balanced XLR (8x in extended monaural configuration)
2x Single-Ended RCA (4x in extended monaural configuration)
2x Single-Ended BNC (4x in extended monaural configuration)

Input impedance Balanced (XLR): 100kΩ or 600Ω
Single-Ended (RCA and BNC): 50kΩ or 300Ω
Maximum input level Balanced (XLR): 16V RMS
Single-Ended (RCA and BNC): 8V RMS

Analog outputs

Frequency response DC - 1MHz
Total Harmonic Distortion + Noise < 0.001%, 1kHz, unity gain
Signal to Noise Ratio 130dB, unity gain and at maximum input level

Volume control

Topology 20bit R-2R resistor ladder network
Range 118dB range in 0.5dB steps, from -100dB to +18dB

General

Display 480x272 pixels, 24bits color, AMOLED
Mains operation Selectable 100V, 115, 230V AC, 47-63Hz
Power supply consumption <1W (standby), 100W max in operation
Dimensions/Weight 440 x 440 x 133mm (W x D x H), 20kg
Remote control

IR remote control provided, RC5 codes
Ethernet based system control via the Android CH Control App

Adobe-PDF-Document-icon Product flyer
Adobe-PDF-Document-icon User manual
Compressed-File-Zip-icon L1 firmware version 1.5
androidapp CH Control Android Application v1.2.1