In the RA7300, each amplifier channel is designed with a power supply on a single printed circuit board and there are separate power supplies for each channel bank to minimise crosstalk, noise and distortion. This approach also provides for ease of replacement and any system maintenance required in the future. As a result, the RA7300 can deliver seven channels of 300 watts RMS power at 8 ohms and 450 watts RMS at 4 ohms. Unusually, these numbers appear to be based on reality, with all channels being driven from 20Hz to 200kHz with no more than 0.05% THD at 8 ohms or 4 ohms. The RA7300 uses dual-DC servos to ensure that DC offset is as a minimum and thermal-track transistors maintain the power amplifier at its optimum bias point, independent of the amplifier temperature. The RA7300's fully balanced differential topology doubles its slew rate and reduces noise by half, whilst the use of current feedback increases amplifier speed. The amplifier also has a frequency response of +/- 0.1dB from 20Hz to 20kHz with 1 watt output and a power bandwidth from 5Hz to 100kHz. Despite all this power, the RA7300 meets or exceeds all international standards for standby power consumption including the new 1/2 watt standard.
We used a number of our favourite Blu-rays for testing, kicking off with Jurassic Park and the T-Rex attack has never sounded so good. From the rain hitting the car windows to the initial bass thuds that accompany the ripples in the glass of water to the full-on roar of the T-Rex itself, the combination of the RS20i and RA7300 was a masterclass in control and precision. All the sounds, from the music to the dialogue to the effects were perfectly rendered and the entire scene benefited from the soundfield filling the room. The RA7300 had power in abundance but it also had a certain amount of grace and the RS20i was able to take full advantage of the remarkable dynamic range and detail on offer. The sound quality was quite simply superb with no distortion, even at high volumes and the noise floor was incredibly low. Soundtracks could go from a whisper to a scream with remarkable impact and the bass was tight and deep, delivering an impressively subterranean low end when necessary. This effective use of dynamic range was perfectly demonstrated in the soundtrack to Oblivion, with the RA7300 moving from the tiniest flicker of a candle to the utter sonic assault of a nuclear explosion, without breaking a sweat.
- Extremely powerful
- Reference performance
- Incredible bass
- Superb build quality
- Attractive design
- Effective connections
- It's bloody heavy
Datasat RA7300 7-Channel Power Amplifier Review
OK let's get this out of the way first, the RA7300 is big and heavy - really heavy. We don't mean normal amplifier heavy, we mean heart of a neutron star heavy, so you need to bear this in mind. At 75kgs in weight the RA7300 will take at least two people to lift it and with measurements of 22cm x 43cm (48cm with rack ears) x 53cm, you'll need to ensure that wherever you install it can take both the weight and the size. That rather hefty point aside, the RA7300 is an exercise in elegant simplicity, with a plain thick metal facia that is designed to match the styling of the RS20i. The only other feature on the front is a small logo panel that doubles as the on/off button. At the rear we have two AC power cords and power buttons. along with 5 way binding posts for the seven speaker channels. There are also balanced XLR inputs, along with a balanced DB25 input and a DB25 output for pass-through.
Since we were partnering the RA7300 with the RS20i, we used the DB25 connector which made setup quite straightforward, although you do need to select each channel using DIP switches. The reason for this is that the seven speaker terminals on the RA7300 can be assigned to any channel with the DB25 connector, whereas with the XLR inputs you turn the DIP switches off and just connect each channel individually to your pre-amp/processor. That's it as far as setup goes and then it was on to the listening tests and it's fair to say, we were in for a treat. The RA7300 has power in abundance but it's also controlled and precise meaning that the RS20i was able to take full advantage of the remarkable dynamic range on offer. The sound quality was quite simply superb with no distortion, even at high volumes and the noise floor was incredibly low. Soundtracks could go from a whisper to a scream with remarkable impact and the bass was tight and deep, delivering an impressively subterranean low end when necessary.
The RA7300 could drive all seven channels with ease, whilst still retaining plenty of headroom, so there's no question that the power numbers quoted by Datasat are realistic - which makes a nice change. The RA7300 would elevate any system it was added to but when used in conjunction with Datasat's RS20i audio processor the results are just spectacular. This marvellous processor/amplifier combination delivered power, accuracy and refinement in equal measures, resulting in a superb audio performance that sets a new standard for home cinema sound. The Datasat RA7300 might well weigh a ton but when it comes to a serious home cinema setup, this powerful amplifier can do all the heavy lifting without breaking a sweat and it can do it with a surprising amount of grace.
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