Marantz CDR640

Having tested the waters with the low‑cost CDR630, Marantz are now set to challenge professional compact disc recorders higher up the ladder. Paul White takes the new CDR640 for a spin.

While computer CD‑ROM burners have the advantage over hardware audio CD recorders when it comes to price and versatility, there's a lot to be said for the simplicity and reliability of a dedicated CD recorder. Computer‑based systems frequently require you to load the audio material you want to record onto a hard drive, then compile a playlist of the various songs, complete with gap timings, before burning the CD‑R. This is fine if you're already using a computer to edit your album, but if you just want to transfer an existing DAT to CD‑R or duplicate a CD‑R you made earlier, it's a very long‑winded process — and, of course, it ties up your computer for the duration. Admittedly, computer CD‑ROM drives have the advantage of speed once you get to the CD‑burning stage, as they can run at up to four times real‑time speed, but write speed alone isn't the only criterion. You also need to consider the time it takes to transfer your audio onto the hard drive in the first place, plus the time it takes to compile a playlist. If your main requirement is to make one‑off CDs from DAT masters, the dedicated hardware solution is generally faster and simpler than using a computer.

The Marantz CDR630 (reviewed SOS September '98) is the least expensive 'professional' recorder around at the moment (see the 'Better Go Pro?' box for the advantages of using a professional machine), and as a consequence has sold very well, but the company have now followed up that model with the more sophisticated CDR640, which is similarly styled but includes a number of additional useful features and interfacing options.

Look & Feel

Housed in a 2U rackmount case, the CDR640 comes equipped with fully balanced analogue inputs and outputs on XLRs (the sensitivity of the XLR inputs may be set to either ‑10dBu or +4dBu), as well as the more common unbalanced analogue phono outs, but there are no analogue phono inputs. Digital I/O is provided on both phonos (S/PDIF) and XLRs (AES‑EBU), and there are two further multi‑pin connectors, one for an optional hard‑wired remote (the RC640) and the other to allow multiple CDR640s to be controlled together from a custom‑built remote device or a computer.

Physically, the CDR640 follows the same styling as the 630 but with a slightly different control layout, and with the disc drawer located to the left of the front panel rather than in the centre. A large knob sets the analogue record level, while a smaller knob sets the headphone monitor level. Recording time, the currently selected options and the record level are shown in the large plasma display.

Feature Set

In principle, the CDR640 is a relatively straightforward device that allows analogue or digital audio sources to be recorded to CD‑R or CD‑RW, but it boasts a few noteworthy features not generally found on cheaper machines. Perhaps most importantly, there's a user‑programmable audio delay, which means that track start IDs can be written fractionally before the audio starts. When you're creating track IDs from audio levels it's very easy to clip off the start of a track, so adding a little delay safeguards against this. If the source is a DAT tape recorded in auto ID mode, adding half a second or so of delay to the audio signal also means that you don't have to resort to moving DAT track IDs. Furthermore, the CDR640 incorporates a memory buffer to ensure frame‑accurate writing of incoming IDs. Less sophisticated CD‑R machines may process IDs a fraction of a second late.

Another important CDR640 feature relates to the way in which recording finishes. Most CD‑R machines stop automatically after a preset time if no audio is present. This effectively prevents the recording of long periods of silence. It's true that you don't often want to record long silent sections, but I have occasionally been asked to master albums where the final bonus track only appears after a minute's silence, or where a short track of birdsong comes in half a minute after the end of the last track. On a conventional CD‑R recorder there's simply no way to do it, as the machine will always stop. The CDR640 normally stops recording either at the end of the digital source recording (MD, CD or DCC sources only) or after a 20‑second silence — but there's also a manual stop mode that lets you decide when the recording process should stop.

Though not fully implemented on the review model, the CD Sync mode on production models of the CDR640 will work from either analogue or digital sources, with or without subcode — where no track IDs are detected, track starts will be determined via ATL (Audio Threshold Level). If 'Digital' blinks in the display, you know that the ATL level will be used to trigger track IDs. All the main modes relevant for DAT sources were implemented on the review model and checked out fine.

Other professional features include sample‑rate conversion, which can either come in automatically when needed, or remain on all the time. There's a reason for the latter option: if automatic mode is being used and the source material's sample rate drifts by more than a certain amount, the sample‑rate converter will automatically switch in, causing a brief glitch. If there's a risk this may happen, it's better to leave SRC permanently on.

The CDR640 also has the ability to set the SCMS flag so that the recorded disc may either be copied freely, copied once, or not copied at all. Because the CDR640 is a professional machine, it ignores SCMS at its input, enabling recordings made on a consumer DAT machine to be copied.

It's possible to switch in pre‑emphasis when using analogue inputs, though this feature is little used these days, so unless you have a specific need to use it you can safely leave it off. Pre‑emphasised digital source material is automatically recognised, and dealt with accordingly.

Clues to the flexibility of this machine can be found in the Preset menu — a sort of user preferences section. Here it's possible to set whether track incrementing should be manual or automatic (though automatic track incrementing is always used in CD Sync mode). Similarly, the stop condition can be set to auto or manual. In auto mode, when recording from CD, MD or DCC the recorder stops around three seconds after the source player stops, and any long sections of silence within the source material will be treated as wanted audio rather than being taken as a signal to stop. However, DATs do not work in the same way, as their subcode contains no stop information. If the source is either analogue, a digital source without an ID subcode, or a DAT tape, the system still looks for a 20‑second silence to signal the end of recording, unless you use manual stop mode. What constitutes a silence can be set too, using a threshold variable from ‑10dB to ‑70dB in 5dB steps.

Also included in the Preset menu is a digital cascade mode which allows the digital input to be routed to the digital output with no processing. When not in this mode, the digital output will be sample‑rate converted whenever SRC is being used. Of course, this means that you can also use the CDR640 as a stand alone A‑D, D‑A or sample‑rate converter, which is extremely useful.

The CDR640 is a very flexible, good‑sounding CD recorder with all the right interfacing features to help it slot into a pro‑audio environment.

In Use

Using the CDR640 is reasonably painless, though when recording from DAT I found the procedure slightly less flexible than on the CDR630. With the latter machine, one button‑press activates record‑ready mode to capture a single track, while pressing the same button twice initiates record‑ready mode for capturing a whole album. The CDR640 seems to have no mode for automatically ending the recording after one track — you have to do this manually. On a similar subject, which I mention almost every time I review a CD‑R machine, there's no way to automatically stop a recording directly after the last track on a DAT tape. Even though DATs do not output end ID information, it should be possible to come up with a system that recognises a specifically numbered DAT start ID as an end marker.

When you're using a digital source that has no track IDs, such as the output from a hard disk recorder or a DAT tape without IDs, it's possible to enter IDs manually during recording, or set the machine to pick them up automatically from the signal level when a gap exceeding 2.7 seconds is detected. If the source is a DAT tape, a CD, or any other source with valid track‑start IDs, selecting CD Sync makes life rather easier. In this mode, the CDR640 waits, ready to record, until a start ID is recognised, at which point recording commences automatically and track IDs are picked up directly from the source DAT or CD.

After recording, the disc must be 'finalised' to produce a table of contents that a commercial CD player will recognise. This takes only a couple of minutes, and once a CD‑R disc has been finalised, no more recordings may be made to that disc (though a CD‑RW can be 'unfinalised' if you use the Erase function to remove the table of contents). CD‑RWs may also be erased one track at a time, starting from the last track, or erased completely.

Verdict

On balance, the CDR640 is a very flexible, good‑sounding CD recorder with all the right interfacing features to help it slot into a pro‑audio environment. The audio delay function is extremely welcome, as is the ability to over‑ride the automatic shut‑off after 20 seconds of silence, while having the facility to use the unit as a stand‑alone sample‑rate converter or A‑D/D‑A is a useful bonus. Being able to adjust the silence‑detecting threshold is also important, especially when working from analogue sources that may have a relatively high noise floor.

The CDR640 is a sensibly designed workhorse of a machine, ideally suited to small commercial studios or serious project studios where making CDs from DAT master tapes is a routine necessity. It may cost rather more than a basic machine, but the additional features mean that you won't get caught out when faced with jobs that are a little out of the ordinary.