AP-505: Awesome sonic impact from a tiny box

TEAC’s new AP-505 is an ultra-compact stereo power amplifier, powered by Hypex Ncore technology, designed also to enable Bi-amping, or use in BTL (Bridge Tied Load/Bridged) mode as a mono amplifier.

Features at-a-glance

The AP-505 – part of TEAC’s Reference range of hi-fi components – produces a maximum 115W + 115W of output power in stereo/bi-amp modes and 220W in BTL/bridged mode. At its heart is an Ncore power amplifier module, made by Hypex of the Netherlands and specially tuned by TEAC’s R&D team, for superlative sound quality
 
By employing a fully-balanced circuit design from the input section to the output stage, the AP-505 keeps the audio signal as unadulterated as possible as it moves through the amplifier, the result being extremely low distortion levels and an excellent signal-to-noise ratio (assisted by the effective elimination of common-mode noise).
 
In the power supply, the AP-505 employs a high capacity toroidal-core transformer, with Schottky barrier diodes in the rectifying circuit. Unlike conventional diodes, Schottky barrier diodes reduce rectifier noise, leading to a ‘cleaner’ supply and a more stable delivery of current.
 
It makes no sense to design an amplifier that delivers excellent sound to a pair of speakers but which itself generates distracting operating noise from a cooling fan. From the outset our engineers were determined to use a circuit and layout that would allow sufficient natural cooling, one that would allow the creation of a compact but powerful amplifier which didn’t need the help of a cooling fan.
 
At the input stage, where sound quality is fundamentally defined, high-quality MUSES8820E dual op-amps are employed for both the XLR and RCA inputs. In the power supply section for the input stage, both the left and right channel rectifying circuits are completely independent from the power transformer onwards, and employ four, high-capacity, 4700μF capacitors on each channel (8 in total), achieving clear soundstage separation between channels.
 
At the XLR input section, a well-designed circuit delivers excellent signal integrity, thanks in part to the elimination of coupling capacitors that can often lose audio information as a signal travels through them.
 
As for the exterior, lightweight aluminum-alloy panels cover a very robust steel chassis. A pair of large level meters add visual interest when the amplifier is in action, while TEAC’s patent-pending ‘Pin-point’ feet, located at three strategic positions on the underside, add incision to the sound, helping to create a more detailed and stable stereo image.
 
And the finishing touch? Retro analogue level meters on the front panel that move in response to signal levels, giving a visually pleasing confirmation that the amplifier is doing its job. A four-step dimmer (bright, mid, dim off) allows users to adjust the intensity of display to their taste, while a switchable sensitivity (±0dB, +20dB, movement off) allows you to enjoy more, less, or even no meter movement, if preferred.
 
Delivering a huge amount of power from such a compact package, the AP-505 offers high sound quality and precision engineering that’ll please audiophiles everywhere.