Moon 750D review

Simaudio claims that the Moon 750D contains not only its most advanced digital-to-analogue converter yet, but that it's the first true 32-bit fully asynchronous digital audio player to reach the market.

It also describes this substantial machine as a DAC plus a transport, which is odd given that in most respects it seems to be an integrated player. It's the plethora of inputs and the fact that it can accept high-res digital signals that explains this approach.

The 750D is a superbly built player from a company that has extremely good form, so expectations are high for this new midrange model.

DAC or player?

Not many companies claim 32-bit conversion for their DACs. In fact, we could only find one other, namely Cary, whose Exciter DAC uses an AKM chipset.

In practice, there is no such thing as a 32-bit DAC, because all contemporary DACs are low-bit types that oversample at a high enough rate to give what is usually 24-bit resolution, but there's no reason why you can't run them faster.

MSB's Platinum DAC operates at 80-bits in its DSP, but the company only claims a bit depth of 26-bits and that's because it builds its own converters.

Ultimately, 'bits' are misleading because however many the DAC claims to use, any advantages are going to be lost in noise, so dynamic range is a more useful description of a DACs capabilities.

Moon claims the SABRE DAC, is greater than 130dB, while the best result that can be achieved with a good 24-bit DAC is just 144dB. Moon's description of the 750D as a DAC with a transport rather than a regular integrated player is backed up by the unusual range of digital inputs provided on its back panel.

As well as RCA phono and Toslink for electrical and optical S/PDIF inputs, it can accept AES/EBU inputs via XLR and has a USB socket. This should mean that if you have high-res music files on your laptop and the software to play them back, you can do so via this player.

I discovered, however, when talking to Moon's Dominique Poupart, that as it stands the USB input is limited to 16/44 operation. The other inputs will accept sampling rates up to 24-bit/192khz, so all you have to do is find a source that can output such a bitstream.

According to Moon, the SABRE DAC/filter achieves 'unprecedented jitter immunity and low-level linearity'. I don't know about the measurements, but it certainly sounds uncommonly clean, which would suggest that there is substance to this claim.

The transport side of the 750D is isolated by Moon's M-Quattro suspension system. This is a gel-based mounting that dampens resonances produced by the transport mechanism and the disc's rotation. The latter is useful because the majority of CDs aren't centred and can create quite a lot of extraneous energy when spun at a CD's high revs.

Analogue output connections are high quality examples of RCA phono sockets for single-ended and XLRs for balanced, while digital outputs come in electrical coaxial and AES/EBU forms.

Unusually, the 750D has two XLRs marked for external power supply, presumably something along the lines of the Cyrus PSX-R, which the manual says will be made available for this player in future.

Heavy metal

As you have a right to expect at this price, the Moon 750D is extremely well put together and suitably hefty. Its chassis is made up of aluminium slabs that have been precision machined to fit together perfectly.

The triangular section corner posts have threaded holes in their bottoms and Moon supplies four conical spikes to screw in. It also supplies little dimpled discs to put under the spikes to stop them from damaging a wooden surface.

The drawer is particularly nicely machined from a slim aluminium section and it opens with the sort of smoothness that you only get with high-end players – there are no clunks or whirring of motors here.

The front buttons are logically laid out for the most common functions, but the inscriptions are a little on the small side for more in-depth use. Most are replicated on the remote handset, which is another slab of alloy – this time powder coated, rather than machined.

This is intuitive to use and has volume and source functions that operate other Rc-5 protocol components. It also has an eject button, but none for track entry.