What do you get when you cross a CD player, a USB socket, an SDHC card slot, a DAB+ tuner, a FM tuner and a Bluetooth audio receiver? Stephen Dawson finds out.

We should probably pause a moment to mourn the passing of Dick Smith (the business, that is, not the man). But recognise that it has been quite a few years since it handled the kinds of products that originally made it a pioneer of electronics retailing. Happily, others have taken over. Altronics originated over in the West, but these days has a presence in Sydney, Melbourne and Brisbane, and when it comes to the nitty gritty of electronics parts and components and specialised electronic devices, it’s heaven to the tech nerd.

So of course it has all kinds of specialised devices that you will never see at Harvey Norman. And here is one that many businesses are likely to find extremely useful: the Redback A2706 CD/MP3 player with DAB+/FM tuner and Bluetooth.

What is it?

The A2706F is a component-width device (with removable rack-mount ears already attached) that would act as a versatile audio source for just about any place that wants to provide audio throughout a business premises. It allows the playback of music chosen by the proprietor, and/or audio from the DAB+ and FM tuners.

I’m generally not one to use ‘and/or’ in my reviews, but it seems appropriate in this case because you can have up to three sources running and outputting simultaneously, or you can use a common output instead and allow the unit to prioritise which source will play.

So what are the signal sources? There is a CD player, a USB socket for flash memory or a hard drive, an SDHC card slot (SDHC supports up to 32GB), the DAB+ tuner, the FM tuner and a Bluetooth audio receiver.

Missing is an AM tuner.

There are four sets of stereo RCA analogue audio outputs. One is dedicated to the section which contains the CD, USB and SDHC players. One is dedicated to the DAB+ and FM tuners. One is dedicated to the Bluetooth player. So you can, if you like, simultaneously play, say, music from USB, a DAB+ radio broadcast and music from a Bluetooth audio device to three different audio circuits in your establishment.

But the final set of outputs is labelled ‘Priority’. All three of the other outputs are also routed to this one, but of course they aren’t mixed. Your choice (there’s a key for this selection) of CD or USB or SDHC plays if there is any media present and the play button has been pressed. If not, the ‘Priority’ output is switched to Bluetooth if any music is playing from that. And if not, it is finally switched to either DAB+ or FM according to your selection.

The point of this is clear enough. You might want to play a particular CD throughout your establishment and then, when it finishes, have the system revert to ABC Jazz from DAB+.

There is an extra set of RCA connections on the back, but these are inputs, not outputs. It turns out that in addition to all this, the unit can record audio to either USB or SDHC. If you want to record DAB+, you connect the DAB+ outputs to the input using a standard audio cable (several are supplied with the unit), then select ‘Aux’ as the recording source.

You can also record to USB and SDHC directly from the CD player without using an external cable, and copy MP3 files from a CD-ROM to USB or SDHC, and from USB to SDHC or vice versa.

The front panel is in two distinct sections. The left half has the CD, USB and SDHC slots, a backlit LED display for showing what’s happening with that section, and a dozen control keys. The right half has another backlit LED display to show the tuner status, 10 control keys and a jog dial.

There’s also an infrared remote control which duplicates some of those functions, but adds additional ones for setting tuner presets and so on.

In use

Unlike so many modern devices, there isn’t a great deal of setting up required. Just work out which outputs you want to use and plug them in, and connect the antenna (the same one is used for DAB+ and FM). An F-type connection is provided for this, with a telescopic antenna provided. I’m in a weak signal area so I just screwed on the cable leading to my outdoor antenna.

Setting up the FM presets was a bit fiddly, in large part because it relies on using a sequence of keys on the remote control, and the layout of the remote is rather haphazard. That’s only a one-off, though, so just have the instructions to hand and you’ll get through it.

Actually, keep them handy until you get used to things because some of the front panel keys are also confusingly labelled. For example, on the CD/USB/SDHC side, the keys with the usual skip logos don’t perform that function. Instead the fast forward and rewind keys do double duty: fast forward and rewind when held, skip when pressed briefly. On the DAB+/FM/Bluetooth side there are two ‘Down’ keys and two ‘Up’ keys. One of each is for the tuners, while the other pair is for the Bluetooth function, although all that isn’t immediately obvious.

With that mastered, it all worked very nicely indeed. The sound quality from the CD player and MP3 files on USB and SD was generally fine. Sometimes there was a little leakage from the tuner – at perhaps 40 or 50dB lower in level – from the tuner (whichever was selected) into the dedicated CD output. This tended to be audible only in the silence between tracks, and only from my high quality desktop speakers. In an installation this would not seem likely to be audible.

It likely won’t matter in most installations, but the left and right channels were swapped using this section, both through the dedicated outputs and the priority one. Using the Bluetooth section of the unit, the channels were the right way around.

The FM tuner sounded about as good as an FM tuner can, which is to say: okay. Noise suppression was good and the stereo separation solid. The DAB+ decoding was clean and produced fine quality sound.

The Bluetooth connection worked effectively, although the sound was a touch less focused and dynamic than with the same music from CD. It seems that there is no support for high quality codecs in the Bluetooth section (e.g. AAC for Apple devices or aptX for the others) so the connection uses the standard SBC codec. The output level from the Bluetooth section seemed noticeably lower than from the other sections. Some amplifier knob twiddling would likely be required when switching between the Bluetooth and the other sources.

Recording

The recording function could be very useful. You could put 90 hours of MP3 music copied from CDs onto a cheap 8GB flash drive for continuous cycling, rather than having to switch CDs every 40 minutes.

The unit records differently depending on the source. For analogue inputs (e.g. from the DAB+/FM or Bluetooth outputs on the unit) it creates a 128kbps MP3 file. This tended to be fairly high in level. With some commercial talkback radio the peaks were quite heavily clipped. Recording quality music from ABC Jazz didn’t result in any clipping, but there was still clearly a transfer at a high level and the played back music sounded a touch forced, even when reduced in playback level to match the original.

There are two options for recording tracks from a CD. If you want the whole thing, you just pop the CD in the slot, make sure it is stopped and then press the Rec/Del key. The disc will start up and start playing and copying to MP3 on USB/SD in real time. For a specific track, start it playing and press the Rec/Del key. The playback will jump back to the start of the track and only that track will record.

The internal recording from CD did not seem to be analogue. Comparing the waveform of an MP3 recorded from CD on this device with the original CD waveform, there were only a couple of tenths of a decibel of difference between the two here and there, and that could be attributed to the MP3 compression. I’d say that the MP3 encoder worked directly on the PCM output from the CD section.

It also created higher quality MP3 files, using a 192kbps constant bit rate and leaving the high frequencies intact out to 20,000Hz (many MP3 encoders trim the high frequencies above 16,000Hz, especially at lower bitrates).

If you’re recording from, say, DAB+, then the DAB+ output from the ‘Priority’ connection mutes to a very low (and rather scratchy) level. So to record and listen at the same time, a couple of RCA splitter plugs should be used on the main DAB+ outputs to feed the recording input and the amplifier simultaneously.

Conclusion

The Redback A2706F is a versatile source device that would be suitable for many commercial applications.