Higher-end modern amplifiers may have an optical input, in which case you can run an optical cable (not included) from the DAB to your amplifier. Given the low bit rate of DAB, you're unlikely to hear a massive improvement over the phono interconnects, but you will eliminate potential problems with ground loops etc.
Every UK DAB broadcast is compatible with the ST-SDB900 -- all Band III transmissions can be received on the tuner at up to 256Kbps. If you're not convinced by DAB, or are having reception problems, FM frequencies available to the Sony range from 87.5 to 108MHz. Again, this encompasses all commercial FM broadcasts in the UK.
FM, AM and DAB bands can be tuned using the dial on the right of the unit, and the unit includes a range of view options, including the ability to sort stations alphabetically.
Sony claims to have used independent power supplies to isolate the audio and DAB circuits from the other circuits in the ST-SDB900. This was difficult to verify, but a cursory examination of the inside of the radio made it possible to identify what appear to be different power stages. This should make for a cleaner sound -- more on that later.
Efforts have been made to dampen the circuits and the chassis, and vibration is minimised by polycarbonate on the rear panel, teflon on the side panels and a 'bonded material' on the front panel. Though hi-fi isolation is dismissed as an old wives' tale by cynics, many audiophiles swear by the minimalisation of vibration in their separates. Some go so far as to place bricks on carefully chosen pieces of equipment. Given this behaviour, there may well be something to the ST-SDB900's floating construction.
Power is supplied via a sturdy kettle-lead style connector. AM, FM and DAB aerials attach to the rear of the unit -- Sony includes all three types of aerial and these are easily attached.
Auditioning the ST-SDB900 with a Radio 4 DAB broadcast illuminated the unit's strengths in producing an accurate and well-balanced sound on our reference amplifier and speaker set. Though DAB is still at the mercy of radio engineers who love to compress -- not to mention the low bit rate of UK DAB broadcasts -- the ST-SDB900 compares very well to other tuners in its class.
Listening to Radio One was, again, comparatively good. Within the limits of the broadcast, the sound quality was rounded, not too bright and not excessively bassy. The broadcast was, however, noticeably muddy with compression -- something that's problematic for all separate tuners. The sad fact is that the DAB signal just doesn't stand up when heard on a good stereo system and for music, in particular, is a disappointment. Spoken-word broadcasts, however, are exceptionally clear.
There's very little to divide the hi-fi DABs we've looked at so far. They're all like very talented artists being made to paint with crayons. The DAB bit rate can't tax these tuners.
For appearance, this Sony DAB may not have the edge, but for simplicity of set-up it's hard to beat. The ST-SDB900 is definitely worth considering if you want to bring DAB into an existing hi-fi setup, and for owners of a Sony amplifier this tuner is definitely the most logical choice for expansion.
Edited by Mary Lojkine
Additional editing by Nick Hide