Усилители мощности стерео — Boulder 3060

The 3060 is a stereo power amplifier running in Class A, made by Boulder Amplifiers of Louisville, Colorado, and sits in the 3000 Series next to the 3010 preamplifier and the 3050 mono amplifier. The design was derived from the 3050, keeping as much of that monoblock's performance as possible while lowering maximum output and splitting the chassis into two channels. Production is extremely limited and each amplifier is assembled only after an order is placed.

Key specs that matter

Continuous output is 900 W per channel, and Boulder states that this figure holds into 8, 4 or 2 ohm loads. Voltage gain is 26 dB and equivalent input noise is 1.5 uV over a 20 kHz bandwidth. At 900 W into 8 ohm, THD is 0.0006% from 20 Hz to 2 kHz and 0.0025% at 20 kHz, rising to 0.0012% and 0.0045% into 2 ohm. The response is flat from 20 Hz to 20 kHz within +0.00 and -0.04 dB, and the -3 dB points sit at 0.015 Hz and 200 kHz. Balanced XLR input impedance is 200 kohm. The amplifier alone weighs 161 kg, with a further 39 kg for its base.

Engineering and use context

Every channel carries two of Boulder's 99H gain stages, a surface-mount, fully discrete and epoxy-potted circuit reserved for the 3000 Series, with the first stage supplying 20 dB of gain and the output stage the remaining 6 dB. The output section has 60 bipolar transistors per channel clamped to heatsinks cut from solid aluminium billet. An analogue bias circuit raises bias on transients and lowers it over 28 seconds, keeping the amplifier in Class A without constant full power draw. Four toroidal transformers float in a shielded, resin-potted steel tube, and 48 filter capacitors follow rectification, while a separate regulated supply runs the microprocessor. All supplies are linear. Protection covers current limiting, DC at inputs and outputs, supply failure and a thermal limit at 95 C on the transistor cases. The chassis halves are mirror images machined from 6061-T6 aluminium, and every unit ships with a machined aluminium and polished stainless steel base.

Pairing

With XLR-only inputs, a sensible partner is a balanced preamplifier like Boulder's own 3010, and Boulder Link lets a 3000 Series master component sequence power-up and pass volume and protection messages, with Ethernet available for IP on and off control. Speaker cables need spade lugs for the two parallel pairs of spade-only terminals, and the unit runs only on 240 V mains through a 32 A IEC inlet.

Alternatives

Boulder's 2160 from the 2100 Series is a lower-powered stereo amplifier with a dual-mono layout.