A Novice’s Review of the M-Audio Transit USB

I use a Yamaha CD recorder with hard drive at home but wanted a digital recording device for portable use with a lap-top. I only need line-level recording capability at present, mostly for recording from satellite radio or vinyl LP via a pre-amp. Having located Dolphin Music on the web and being impressed with their site, I asked them for advice by email. Their response was prompt and to the point. For my purposes, they recommended the M-Audio Transit, which I duly ordered. Dolphin Music’s service was excellent and the Transit arrived safely within a couple of days.

The Transit is astonishingly compact and light and really can be carried in your pocket or handbag. It comes with a bundle of dedicated software, a USB lead and optical digital input adaptor, but you need to supply your own audio connecting leads. Its compact size make it ideal for use on the move.

Loading the drivers, both sets of software and hooking the Transit to the laptop was straightforward. But I am a novice at computer recording and I found the software supplied with the Transit daunting. Although the on-screen guide to the virtual knobs, sliders and buttons is helpful, the instructions for using the Live software are not easy to follow. The difficulty is aggravated by the fact that it is impossible to print out the instructions, so they have to be read on-screen, presumably for the sake of copyright protection. I spent a couple of hours trying to decode the instructions for the accompanying Reason software and gave up. Unless you already understand studio recording equipment and techniques Reason would seem to demand a lot of study and practice. It took me an hour to figure out you could not use it to record anything!

After some tentative experimentation and only one telephone call to M-Audio’s technical support team I managed to make a simple stereo recording from an analogue source using the Transit and the Live software. I got a lot of helpful advice from M-Audio about setting up the lap-top to avoid interference from other hardware and software and found the recommended website "musicxp" very informative. The quality on playback compared very favourably with any DIY digital recording I had heard before, although I did notice some distortion caused by clipping at peak levels.

Further attempts produced similarly impressive results but the Transit and Live combination defied all attempts to eliminate audible clipping. This was also clearly visible in Live’s on-screen waveform display. The clipping problem was not so marked with the Transit drivers set to 16-bit/44kHz but at 24-bit/96kHz it was severe and persistent. Sources with a large dynamic range clipped at every combination of bit and sampling rates offered by the control panel. One of the attractions of the Transit is that it offers 24-bit/96kHz recording capability as well as CD quality 16-bit /44kHz. I was disappointed to discover that I might not be able to benefit from the higher quality the Transit promises. I tried all the recommended tweaks to the laptop but to no avail. I should say that the laptop in question is only a few months old and far exceeds the requirements specified by M-Audio so I was surprised it would not work properly. Input levels can be set on-screen using Live but to no avail. Whatever amount of attenuation was applied to the line-in signal the clipping remained. None of the supplied instructions addresses the issue or offers a clue as to the possible remedy.

After much reflection it dawned on me that the problem had nothing to do with the lap-top or the software. The controls I had been using were all virtual not real. In other words, nothing I was doing to attenuate the digital “line-in” signal on-screen was having any effect on the actual analogue signal entering the Transit. I remembered that with analogue recordings using different line-level sources it was usually necessary to reset the gain controls on the recorder to compensate for the very variable output signal strengths associated with different equipment. There seems to be no universal standard for “line-level”. So I disconnected the Transit from the line-out connection on my pre-amp and hooked it up to the headphone socket. Low and behold by use of the pre-amp’s volume control I was able to eliminate clipping entirely, for all bit and sampling rates.

Now I feel a bit silly, first for not realising that this would be necessary and then for not asking Dolphin Music the right questions in the first place. It is obvious now that nothing that happens in the lap-top is going to have any bearing on the analogue signals going into the Transit. Looking at other external sound cards on Dolphin Music’s website I see that most of them have some sort of gain control, albeit at a higher price point. I am also a bit miffed because I had to discover this the hard way. M-Audio do not explain this in their sales literature or specifications and the minimal instructions issued with the Transit offer no help or guidance about actually making a recording. When I ordered the Transit I had assumed that it must have some sort of in-built recording peak signal limiter like most Nicam VCRs and some cassette and voice recorders I have used in the past. I was sceptical about the impact this might have on ultimate sound quality but as there was no mention of the need to attenuate line-level signals I assumed the device must be self-regulating. I wish now that I had asked explicitely how the analogue signal was controlled before I ordered the Transit.

I have no idea whether this is a problem common to all sound cards without separate gain controls. One might suppose that it would be true of most internal PCI cards so it is disappointing that so little guidance appears to exist for the uninitiated.

To sum up then: the Transit is capable of making excellent digital recordings, provided that you can master the relevant software and provided that you realise you will need independent control of the analogue signal the device is receiving at so called line-level. Once you have factored in the cost of attenuating the line-level signal in a way that does not degrade its quality – the headphone outlet on most pre-amps not being ideal – you would probably be better off spending a bit more on a purpose built sound card/interface with integral gain control.

As a newcomer to the world of computer audio recording I am sufficiently impressed with the Transit’s essential quality that I am already thinking of making the necessary upgrade myself.