four.valve Limited 55 Edition rotary mixer

Overview

To mark 55 years of the Technics SL-1200, Union Audio has created the four.valve Limited 55 Edition.

Based on the four.valve, the Limited 55 combines its valve-based analogue architecture with selected design elements from the elara range, including the aluminium front panel and knurled control knobs.

The mixer also features weighted fader knobs and wooden side trims from the Signature Series, with gold anodised bezels and artwork designed to complement the Limited Edition SL-1210 MK7.

Only 550 individually numbered units will be produced.

Product Description

The Limited 55 retains the four.valve's valve circuitry and fully analogue signal path, delivering the harmonic character and natural compression that define the four.valve design.

A custom discrete op-amp designed by Union Audio founder Andy Rigby-Jones has been developed specifically for this edition, forming part of the analogue signal path.

The physical design combines elements from across the Union Audio range. The aluminium front panel and knurled controls are taken from the elara family, while weighted fader knobs and wooden side trims come from the Signature Series.

Gold anodised bezels and artwork complete the finish, while the VU meters feature a phosphorescent treatment.

The result is a four.valve with a distinctive new finish and a combination of design details not found on any other Union Audio mixer.

Tech Specs

Distortion plus Noise (THD+N) un-weighted

0dBu, 20Hz to 20kHz, Line In to Mix Out +4dBu

0.1% Typically

Frequency Response

Line in to Mix Out	+/-1dB 20Hz - 50kHz
RIAA Accuracy	+/-1dB 20Hz to 20kHz

Shutoff and Crosstalk

Fader Shutoff	> -80dB
L/R Crosstalk Line in to Mix Out 1kHz	<-75dB

Noise 22Hz to 22kHz Un-Weighted

Residual Output noise	<-92dBu
Line In to Mix Out Unity	<-85dBu

Maximum Output Level Mix Out

0.5% THD

+27dBu

Dynamic Range

Dynamic Range

116dB

EQ and Filter Frequency

Channel High-Pass Filter Fully Clockwise	-3dB/1500Hz
Master 3 Band Isolator	200Hz, 800Hz, 2000Hz

Headphone Amplifier

Maximum output level

750mW RMS - 33 ohms

Power Supply

Type	External SMPSU
Mains Voltage range	90-260VAC
Output	18V DC 30-40W
Efficiency	LEVEL VI

Dimensions

Dimensions - four.valve

Mixer Height	100mm (inc. knobs)
Mixer Width	365mm
Mixer Depth	283mm
Weight	4.75kg

Packed Dimensions - Four.valve

Size L x W x H	48cm x 38cm x 20cm
Weight	7kg