Parasound Halo A 31 THX Ultra2 Power Amplifier

Parasound announced a three-channel home theater power amplifier to its premium Halo product family. The THX Ultra2 certified Parasound Halo A 31, which is rated at 250 RMS watts per channel, is sonically identical to the company’s five channel Halo A 51 and two channel Halo A 21 amplifiers.

The A 31 was developed for Parasound customers who want their surround systems to include uncompromised reproduction of stereo music. The A 31 is ideal for this because it also provides matched amplification for the center channel speaker.

The Parasound Halo A 31 provides high-bias Class A/AB operation with pure Class A operation up to 7 watts per channel. It easily delivers 250 watts per channel into 8 ohms and 400 watts into 4 ohms, all channels driven. Exceptional sound quality is maintained with XLR balanced inputs as a step-up alternative to the RCA single-ended inputs. Parasound’s traditional Halo topology employs matched pairs of complementary JFETs for its input-pre-driver stages, matched pairs of complementary MOSFETs in its driver stages and 8 beta-matched 15 amp, 60 MHz bipolar output transistors for each channel.

The A 31 is direct coupled, and uses no capacitors or inductors in signal path with full power output down to 5 Hz. The loudspeakers are connected via heavy-duty 24k gold-plated five-way speaker terminals, and each is relay protected.

The power supply consists of a 1.35kVA encapsulated toroid power transformer with independent secondary windings for each channel. Power stability is maintained by four premium power-supply filter capacitors per channel totaling 94,000µF, and protected by DC servos and relay protection circuits.

The Parasound A 31 provides a gain control for each channel offering ±6db relative to THX reference level. This enables the A 31 to play louder in very large rooms and facilitates level matching with other amplifiers. Other features include: auto turn-on options by an audio signal with a threshold adjust or a 12v trigger with input and loop out jacks plus indicators for AC power, channel status, and high temperature. The heavy-duty 4u chassis has rear carry handles, and an included rack-mounting adaptor. The front panel is anodized aluminum.

Possible uses for 3-channel amps:

• Powering the C, LS, and RS channel speakers when a separate two-channel amplifier (or pair of monoblocks) is used for the L and R channel speakers.
• For L, C and R “one wall” theater systems without surround speakers.
• Powering the LS, RS and single back channel speaker in a 6.1 system.

Price and Availability
The Parasound Halo A 31 will be available in April 2012 for $3,000.