Phonostages — Remton audio 481

The 481 is a valve phono preamplifier from Remton Audio, a small manufacturer in Prague, and every unit is handcrafted in Czechia. It was announced as a limited edition, with total production capped at thirty units because the NOS Tesla resistors used in the circuit are scarce. Remton describes it as an upgraded version of its V-LCR model without the LCR network for RIAA correction, and the company places it between the V383 and the V-LCR in its range. The stage accepts MM, MI and high output MC cartridges.

Key specs that matter

Gain is 42 dB, and one single-ended input is provided. Input impedance can be set from 17 kOhm to 100 kOhm, while the capacitance loading steps through 0, 47, 100, 147, 220, 267 and 367 pF. Output impedance is 250 ohm. The RIAA frequency response is quoted as 20 Hz to 20 kHz within 0.3 dB. Four matched ECC81 valves make up the tube complement. The chassis measures 386 x 295 x 85 mm and weighs 7 kg.

Engineering and use context

The RIAA curve is formed passively, and the circuit runs with zero negative feedback. The NOS Tesla resistors were selected for a deviation of only 0.25 dB across 20 Hz to 50 kHz, which is the reason given for their use in the equalisation stage. High voltage for the valves comes from a DC supply with soft start, fed by a toroidal power transformer, and Remton states that components are hand picked for each build. Input and output terminals are gold plated. Two versions were offered - one for moving magnet cartridges priced just under EUR 3,200, and one for moving coil cartridges with built-in step-up transformers priced just under EUR 4,200. The factory warranty runs two years for parts and labour, with 90 days on the valves.

Pairing

With its moderate gain and loading that starts at 17 kOhm, the 481 suits cartridges with an output in the usual MM or high output MC range. Low output moving coil models need the step-up version or an external transformer. The low output impedance suits the line stage of a valve or transistor preamplifier and tolerates a moderate length of interconnect. Capacitance steps up to 367 pF let the owner match the total load to the value a cartridge maker specifies, counting the capacitance of the tonearm cable.

Alternatives

The Remton 481 MK2 is the related phono stage with two inputs, loading down to 36 ohm and three gain settings of 42, 62 and 68 dB for MM and MC use.