Copland CTA407

Copland’s range has always been small, and product life cycles have tended to be long. At the time of writing, this tiny Danish company offers just four integrateds and a DAC/headphone amp. There are no source components, as was once the case.

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Copland isn’t particularly dogmatic about the technology it employs, with its products using solid-state, valve and hybrid circuits. Regardless of the design, we have invariably liked what we have heard, and that certainly applies to the range-topping CTA407 integrated stereo amplifier we have here.

This is currently the only all-valve stereo amplifier the company makes, and as such demands a little more from its owner. Take the Copland CTA407 out of its packing and you will find that it is a reasonably chunky unit. Your first task is to install the quartet of output valves, supplied in matched pairs. Our review sample has 6550-type valves but the CTA407's circuit is happy to accept any from the KT90/KT100/KT120/KT150 families and automatically adjust accordingly.

The output circuit is a push-pull, ultra-linear design that delivers 50 watts per channel into both 4and 8-ohm speaker loads. On paper, it is possible to push the valves harder and double that power output figure, but Copland has chosen to be more conservative on reliability and performance grounds.

Installation of the output valves isn't difficult, but it does require the removal of the lid. You will need a 2.5mm Allen key and the patience to take out eight bolts. Once that is done it is an easy matter to seat each output valve in place, but be careful to make sure that they are properly pushed into the socket. The smaller valves used in the preamplifier circuitry (12BH7 x 2 and 12AX7) are already installed on our sample.

The clever bit about the Copland's circuitry is its ability to accommodate different types of output valves without issue. Not only does the circuit's servo-based system automatically adjust bias current for each type of valve, but it also operates as part of the amp’s high-pass filtering network, something that is claimed to improve the CTA407's performance significantly.