YBA Passion PRE550/AMP650 pre/power amplifier Lab Report

The flame in YBA's Passion duo is undoubtedly provided by the AMP650 which has two outputs – direct (the lower 4mm speaker terminals) and via a series inductor network (upper 4mm terminals). Power output meets the 200W/8ohm spec. at 2x223W/8ohm with sufficient in reserve to accommodate peaks of 252W, 460W, 650W and 628W (protected) into 8, 4, 2 and 1ohm loads at <1% THD [see Graph 1]. Distortion is a very steady 0.07% from 1W to 50W/8ohm but increases thereafter to 0.1%/80W, 0.2%/130W, 0.4%/180W and 0.75%/200W (all 1kHz), and at HF to 0.12%/20kHz (10W). The response is very extended into the low bass at +0.2dB/1Hz up to –0.2dB/20kHz and –3.3dB/100kHz but noise, from the frame transformer is quite high, reducing the A-wtd S/N ratio to just 70.5dB (re. 0dBW).


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 25.2A


Distortion versus 24-bit digital signal level over a 120dB range at 1kHz (black) and 20kHz (blue)

The partnering PRE550A offers a maximum +6dB gain, with distortion from 0.0001-0.001% (20Hz-20kHz) and a ±1dB bandwidth extending from 3Hz-98kHz (–0.05dB/20kHz). Noise is low and the A-wtd S/N wide at 93.8dB, the maximum 18.9V balanced analogue output delivered through an 80ohm source impedance. The digital board, based on a pair of CS4398 DACs offering 99dB of stopband rejection, peaks at a massive 9.1V output and delivers a resolution good to ±0.3dB over a full 110dB dynamic range. Distortion is 0.001-0.023% (20Hz-20kHz, 0dBFs) and falls to a minimum of 0.0001-0.0005% between –10dBFs and –30dBFs over the same frequency range [see Graph 2]. The response holds to a very flat ±0.03dB (20Hz-20kHz) with 44.1kHz/48kHz media, rolling gently away to –2.1dB/45kHz and –12.2dB/90kHz with 96kHz and 192kHz media, respectively. Jitter is impressively low at <40psec for all sample rates. PM

Continuous power (<1% THD, 8/4ohm): 223W / 336W
Dynamic power (<1% THD, 8/4/2/1ohm): 252W / 460W / 650W / 628W
Output impedance (20Hz–20kHz): 0.023–0.041ohm (<140ohm, pre)
Freq. resp. (20Hz–20kHz/100kHz): +0.0 to –0.2dB/–3.3dB (–1.1dB, pre)
Distortion (20Hz-20kHz, pre/power): 0.00013–0.001%/0.065–0.11%
A-wtd S/N ratio (re. 0dBV/0dBW): 93.8dB (pre) / 70.5dB (power)
Digital Jitter (48kHz/96kHz): 40psec / 25psec
Power consumption (idle/rated o/p): 35W / 625W (14W, preamp)
Dimensions (WHD, pre/power): 430x118x412/430x178x397mm
Price (pre/power): £6750/£5750

Bures sur Yvette, France/Shanling, China
Supplied by: Nintronics Ltd, Herts
01707 320 788