Интегральные усилители — Concert Fidelity CDV-2 SP

The CDV-2 SP is a valve bi-amp splitter from Concert Fidelity, the Japanese company whose products are designed by Masataka Tsuda. It belongs to the Reference Series and shares its chassis and circuit platform with the CDV-2 NW, a two-way valve electronic crossover. Where the NW divides the band into high and low outputs, the SP version passes the full signal to two separate output pairs so that one preamplifier can feed two power amplifiers in a bi-amplified system. Pricing is not published on the maker's site, where enquiries go through the distribution network.

Key specs that matter

Audio arrives at a lone stereo RCA input. Two pairs of RCA outputs follow, labelled Output 1 and Output 2, and each has its own individual level control. An output mode selector lets the owner use Output 1 alone, Output 2 alone, or both together. The valve line-up is three 12AU7 or ECC82 double triodes working as buffer amplifiers and one 6CA4 or EZ81 for rectification. The case measures 450 mm wide, 100 mm high and 310 mm deep, and Concert Fidelity gives the net weight as from 10 kg.

Engineering and use context

The maker's rationale for the CDV-2 family is that no single drive unit can reproduce the whole audio spectrum, which is why serious loudspeakers divide the band among bass, mid and treble drivers, and why an electronic device ahead of the amplifiers can share the task between separate amplifier channels. In the SP version that device does no filtering and acts as a valve buffer, so the crossover inside the speaker still does the dividing while each amplifier drives its own section through split terminals. The 12AU7 positions can be fitted with other valves of the same type, as the maker allows tube swapping. On power-up a 30 second mute keeps the outputs silent while the circuit settles. Valves are not supplied with the unit. Every CDV-2 SP leaves the factory wound for the mains of one market, with versions for 100 V, 110 to 120 V, 220 to 230 V and 240 V supplies, and the warranty does not cover failures outside that country.

Pairing

The separate level controls allow two power amplifiers with different gain figures to be matched. Since every socket is RCA, the preamplifier ahead of it and both amplifiers need RCA sockets.

Alternatives

The Concert Fidelity CDV-2 NW uses the same chassis as a stereo two-way or mono three-way valve electronic crossover with filter slopes of 6 or 12 dB per octave.