Stereo power amplifier with 180 W per channel
Chord ULTIMA 6 is a stereo power amplifier delivering 180 W RMS per channel into 8 Ω and 350 W RMS into 4 Ω. Chord Electronics describes it as currently the least expensive way into the next-generation ULTIMA family of stereo power amplifiers.
The design starts from the model that preceded it, the SPM 1050 MK II, and adds the ULTIMA amplifier topology. It runs in class AB with sliding bias, on fully balanced circuitry and with convection cooling.
Sixteen MOSFETs and dual feed-forward correction
The dual feed-forward error-correction circuit is the work of John Franks: the manufacturer describes it as the result of 30 years of development and as its first all-new circuit in three decades. Chord credits this topology with a very fast response and with power reserves that do not run short.
The output stage uses 16 proprietary power MOSFETs, TO3-style, dual-die and lateral-structure devices, matched to one another. They are driven by an ultra-low-distortion, high-voltage amplifier operating at 300 V per microsecond, and an error-correction circuit monitors them continuously. The inputs are balanced, with DC-tracking servos and full temperature compensation.
Chassis, controls and connections
The casework is solid aircraft-grade aluminium, with a redesigned 28 mm thick fascia that follows John Franks' latest aesthetic. The power button, a recessed polycarbonate sphere, lights up in standby and in operation; a switch hidden in the vertical split line of the front panel dims the lighting. The top light ring is included.
The rear panel carries the balanced XLR and unbalanced RCA inputs, the loudspeaker terminals, the 12 V trigger input and a C-19 type IEC mains socket. The Integra side legs are included (480 × 180 × 360 mm, W × H × D); gloss black acrylic side blocks are available as an option, reducing the size to 420 × 150 × 360 mm, although the amplifier can then no longer be stacked. The options also include Integra legs in Jett Black or Argent Silver.
Technical data
- Output power: 180 W RMS per channel into 8 Ω; 350 W RMS per channel into 4 Ω.
- Inputs: 1 balanced XLR stereo pair and 1 unbalanced RCA stereo pair, gold plated.
- Trigger: 1 × 12 V input (Chord Electronics auto start).
- Outputs: 1 pair of gold-plated, high-current loudspeaker terminals.
- Operating class: AB with sliding bias.
- Power devices: 16 proprietary MOSFETs.
- Frequency response: 0.5 Hz - 100 kHz (−1 dB).
- Total harmonic distortion: 0.005 %.
- Gain: 30 dB.
- Power consumption: 1,500 W at full power; 10 W in standby.
- Dimensions with the included Integra legs: 480 × 180 × 360 mm (W × H × D).
- Dimensions with the optional side blocks (not stackable): 420 × 150 × 360 mm.
- Weight: 22.4 kg.
- Finishes: black or silver.
- Included: 15 A IEC mains cable.
