The veteran and renowned Swedish firm Copland, one of the most traditional Hi-Fi icons, has just launched the CTA407, an integrated stereo amplifier with 100% tube architecture that was created with the aim of enhancing the role of the aforementioned component as an interface between the signal sources and the loudspeakers, in order to bring the restitution of music to its highest levels of naturalness. Of this distinguished electronic music, the fact that its creators have compromised the usual conceptual simplicity of Copland’s achievements by introducing a complex circuitry designed to support audio stages. Thus, the 40 LED’s on the front panel (10 for each of the 4 power tubes) are the visual part of the valve polarization and diagnostic management system that it incorporates, although they can be deactivated if the user so requires. you want it.
As far as compatibility is concerned, the new Copland is will automatically adjust acany outlet valve in the 6550/KT88/KT120/KT150 family, thanks to a key innovation: a servo system that not only adjusts the bias automatically and without loss, but also forms an integral part of the device’s internal high-pass filtering circuitry, closely matched to the transfer function of the amplifier section. Also the connectivity has been very careful, featuring five line inputs (including a loop in/out for monitoring recordings) and one phono input (accommodates moving magnet cartridges and high output moving coil cartridges) based on that of the celebrated CTA405 model. As for the output stagesare of the push-pull type and consist of two power valves mounted in a fixed ultra-linear arrangement that simultaneously provides the low distortion of the triodes and the generous output of the tetrodes. In fact, a pair of push-pull mounted 6550 and KT family tubes can deliver over 100 watts.
By moderating this figure, the CTA407 supplies 2×50 watts in Class A/AB highly biased, which means that in practice the amplifier can supply most of its power in A class. On the other hand, as a consequence of the outstanding quality of the output transformers, a superb linearity before applying feedback, thus reducing the costs inherent in the use of internal compensation circuits and ensuring a high stability before closing the loop with negative feedback of 18 dB. The result of this meticulousness is a extraordinarily accurate music restoration without the slightest tendency to listen to fatigue, to which is added robust dynamics and great flexibility when choosing loudspeakers.
Technical characteristics
- Very high performance integrated stereo amplifier.
- 100% tube circuit topology.
- Executed with audiophile grade components.
- System of automatic polarization without losses of the power tubes.
- 5 line inputs and 1 phono input compatible with moving magnet cartridges.
- Phono input sensitivity/impedance: 2.5 mV/47 kohms.
- Push-pull output stages with sw power tubes in ultra-linear configuration.
- Output stages compatible with 6550/KT88/KT120/KT150 valves.
- Output power of 2×50 W RMS in Class A/AB into 8/4 ohms.
- Frequency response of 10-150,000 Hz (-3 dB cutoffs).
- Signal to noise ratio greater than 100 dB.
- Dimensions: 435x215x390 mm (WxHxD).
- Weight: 25 kg.
