Rotel has updated three of its 15 Series stereo components with sound quality improvements and important new features. The three new 15 Series models are the RC-1572 preamplifier (£945), RA-1572 integrated amplifier (£1395) and the RCD-1572 CD player (£845). All will be available in August, but prices have not yet been confirmed.
Common to the new 15 Series models are bespoke, in-house developed and manufactured oversized toroidal transformers and dual differential input stages. Both are designed to ensure large reserves of instantly available clean, noise-free power and minimal stray radiation patterns to corrupt the audio signal.
We’re told that “Nearly all components in the audio paths are ‘through-hole’ rather than surface mounted allowing Rotel to select from a wider choice of true high-end, discrete, components. All circuit components – resistors, capacitors, inductors – are chosen only after their positive contribution to overall sound quality has been individually quantified and verified by extensive listening sessions both at the Rotel HQ and by a dedicated team of audio engineers in the UK.” All three products incorporate “high-end” DACs that feature custom designed external low pass filters.
RC-1572 preamp
Designed to partner the RB-1590 power amp the RC-1572 employs relay rather than IC switching for analogue sources in order to ensure the integrity of the signal path for RCA, phono and XLR inputs. The RC-1572 also features a 32-bit AKM4495 DAC for higher resolution of digital to analogue conversion. “Careful routing of all low level signals ensures impressive signal to noise levels, with the result that the RC-1572 can deliver effortless musical dynamics with impressive detail and scale” it says here. The RC-1572 also boasts an integrated aptX Bluetooth connection and dedicated rear power for Google Chromecast Audio. Analogue inputs include balanced XLR connectors, four pairs of conventional RCA inputs and a moving-magnet phono-stage for vinyl playback.
RA-1572 integrated amplifier
The RA-1572’s circuitry is said to draw on a high capacity power supply based on a Rotel custom designed and in-house manufactured oversized toroidal transformer working together with very tight-tolerance parts including T-Network capacitors to provide large reserves of power. The Class AB output stage uses discrete devices to ensure precise reproduction of all signals regardless of origin with the power output rated at 120 watts per channel into 8 ohms, continuous into both channels. A mono subwoofer output is also provided. The RA-1572 features a built-in 32-bit/768kHz AKM digital-to-analogue converter (DAC) and analogue input stages. The DAC and surrounding circuitry support an array of source inputs including DSD capable USB (32-bit/384kHz). The Bluetooth input supports aptX alongside coaxial (RCA) and optical (TOSlink) inputs. Analogue inputs include a pair of balanced XLR connectors in addition to conventional RCA jacks.
RCD-1572 CD player
The RCD-1572 CD player has a new purpose designed, dedicated CD mechanism along with other circuit refinements. One of its most important features is the Wolfson WM8740 stereo digital-to-analogue converter offering 24bit 192Khz support. Rotel has chosen to bypass the DAC’s internal low-pass output filter in favour of using a separate high-quality discrete part, The DAC also offers full differential voltage outputs allowing the RDC1572 to offer a choice of both RCA and XLR outputs. Unusually in this day and age it does not have digital inputs but is a dedicated disc spinner.