Интегральные усилители — PrimaLuna EVO 300

The EVO 300 is a valve integrated amplifier from PrimaLuna and sits in the third of four tiers of the company's EVO range, where the 100, 200, 300 and 400 series each contain an integrated, a line stage and a two-channel power amp. The US list price was USD 5,495. The stock tube set consists of four EL34 output valves and six 12AU7 small-signal valves.

Key specs that matter

In ultra-linear mode PrimaLuna rates the output at 42, 43, 45 or 48 W per channel depending on the valve fitted, and in triode mode at 24, 25, 27 or 30.5 W. The power valve sockets accept 6L6G, 6L6GC, 7581A, EL34, EL37, 6550, KT66, KT77, KT88, KT90, KT120 and KT150 types, and a high/low bias switch sets the correct point for EL34-type or KT88-type valves. Frequency response is 10 Hz to 50 kHz within 1 dB and 8 Hz to 75 kHz within 3 dB. Distortion is below 0.2% at 1 W and below 2% at full power, with S/N quoted at 86 to 87 dB. Input impedance is 100 kohm, sensitivity for full output at maximum volume is 270 to 300 mV, and maximum gain is 36.5 to 36.9 dB. The chassis measures 405 x 385 x 205 mm and weighs 31 kg.

Engineering and use context

Working outside the audio path, the Adaptive AutoBias circuit uses an array of sensors to adjust valve bias continuously, which reduces maintenance and lengthens valve life. A Bad Tube Indicator lights a red LED next to a failed valve and puts the amplifier into protection mode. The power transformers are custom-wound toroids potted in resin, and the output transformers are wide-bandwidth designs wound in-house. An AC Offset Killer circuit lowers mechanical transformer noise. Signal wiring is point to point with Swiss silver-plated OCC copper, parts include Takman resistors and DuRoch tinfoil capacitors, and the valves sit in ceramic sockets. Source selection uses sealed Fujitsu relays placed at the rear inputs, with volume governed by an ALPS Blue Velvet control turned by a small motor. Switching between triode and ultra-linear operation is done from the remote handset.

Pairing

Line sources connect through five RCA pairs, an AV processor can use the dedicated HT bypass pair, and a tape output is provided. Speaker terminals offer separate 4 ohm and 8 ohm taps, letting owners choose the winding that suits their speakers' rated load. A transformer-coupled subwoofer output switchable between mono and stereo feeds one or two active subs, and the headphone socket is driven by an all-valve, transformer-coupled stage.

Alternatives

Higher up the same range, PrimaLuna builds the EVO 400 Tube Integrated as its larger valve integrated amplifier.