Предусилители — CAAS Elysian Pre-amplifier

The Elysian Pre-amplifier, shortened by its maker to EPre, is a fully balanced line stage from CAAS Audio, a company founded in Yorkshire in 2006 by the brothers Carl and Neil Broomfield. Dr Carl Broomfield, an electronics engineer who specialises in high frequency microwave circuits, designed the hardware, while Neil Broomfield wrote the software and firmware. The EPre belongs to the Elysian reference series alongside the Elysian 100 mono-block power amplifiers, and in 2018 it was listed at GBP 7,200.

Key specs that matter

CAAS fits three XLR input pairs and two RCA input pairs, with one variable output in each connector format. The level control covers 0 dB to -64 dB plus mute in 128 steps of 0.5 dB for RCA-to-RCA and XLR-to-XLR use, and +6 dB to -58 dB when an RCA source drives the XLR output. Input impedance is 33 kohm and output impedance 60 ohm, on the RCA side and per phase on XLR. Input and output each accept up to 4 V RMS per phase. Bandwidth runs from below 1 Hz to above 200 kHz at -3 dB, and 20 Hz to 20 kHz stays within 0.1 dB. THD is below 0.01% at 1 kHz and 2 V RMS, noise sits about 100 dB below signal A-weighted, and DC offset stays under 1 mV. The chassis measures 350 mm wide, 330 mm deep and 80 mm high and weighs 8.6 kg.

Engineering and use context

The case is machined from a single billet of aluminium, finished silver or black, and the left channel, right channel and digital control section each have their own transformer, three 15 VA toroids in total. Twelve discrete regulated supplies feed the audio circuits and seven more run the control logic. Inside are six zero feedback Class A modules, three per channel, and relays pick the module that gives the shortest path for each input and output pairing. With RCA-to-RCA or XLR-to-XLR the path is only the volume network and a JFET buffer. Volume uses silver contact relays switching fixed precision resistors. The signal path is DC coupled with no capacitors, and a DC servo called NIDS holds the offset down. Since the circuits run in Class A, CAAS asks for 20 cm of free space around the case and 30 cm above it. Idle draw is under 20 W and standby under 0.5 W. A solid aluminium handset covers volume, input and mute, and CAAS gives a three year warranty.

Pairing

Because every input is DC coupled, CAAS asks for sources with low DC offset at their outputs. The CAAS Link socket carries a 12 V trigger that lets the preamp wake and sleep CAAS power amplifiers, and CAAS names the Elysian 100 mono-blocks and the Digital Audio Streamer as partners. There is no ground lift switch.

Alternatives

The CAAS Elysian Pre-amplifier II keeps the single-piece aluminium case and dual mono zero feedback layout but moves to a BJT amplifier stage.