Indigo io


For REAL audio work in video making, a bog standard sound card won?t cut it. David Neiger checks out the Echo Indigo io.

Echo produce several professional sound cards but only the Indigo range are designed for notebooks. The Indigo dj is designed primarily for audio playback having two separate outputs with no input, whereas the Indigo io has both analogue inputs and output. The card claims to provide ?professional audio recording for notebook computers.? But does it?

The Indigo io is a PCCard (Cardbus) sound card that is small enough to fit into your pocket and draws power from the notebook directly. The card has two 1/8? stereo mini-jack sockets; one for consumer level (-10dBV) input and the other for output. There is a small volume control for the output and a blue LED that illuminates when the card is active. Echo provide a 2 metre cable with 1/8? plug on one end, two RCA plugs on the other and two RCA to ¼? jack adaptors for connection to your mixing desk. The plugs are all gold plated, which looks nice but really doesn?t add much to the sound quality.

Also included in the box is a sheet with quick setup instructions and a CD with drivers and a software bundle. The manual is on CD, which is a little less convenient than having printed documentation, but something you can live with given that once you have installed the card and worked out how to use the software mixing console, you should not need to refer to the manual again.

Installation was very easy. I simply loaded the drivers off the CD, inserted the card and within a few seconds the blue LED lit up and I was in business.

Distortion Free

Suffice to say the card is good? very good in fact. I initially thought that something was wrong because the output was silent, even turning the amplifier up to full blast. Unlike some of the other sound cards I?ve tested (including the card I was using), there was no discernible noise on the outputs. When the audio started it was clean, free of distortion and very high resolution.  Stereo separation was excellent even though the output is only via a stereo mini-jack. I could close my eyes and using a pair of high quality headphones ?point? to where each of the singers and instruments was located in the stereo field.

You may not want to use this card to listen to your MP3 collection though as the clarity quickly reveals the defects in this lossy sound format. Music which sounded good using consumer grade sound cards or the lousy sound chip built into the notebook suddenly sounded somewhat lacklustre. You could hear phasing errors, packet drop out, distortion, poor equalisation, noise from poorly ripped sources, excessive use of the limiter and other defects which is exactly what you want to hear when you are mastering audio or video soundtracks.

The analogue input line was equally quiet registering below -80dB of noise. However only having an unbalanced input line did lead to problems as I encountered earth loops when connecting the card to my mixer. Still -50dB noise even from the earth loop was not bad, although it would have been better if Echo supplied an external break out box with more input options including balanced line, XLR and digital inputs (optical or coax). A professional input line (+4dBV) as well as the standard consumer (-10dBV) level would also have been nice, but this limitation is nothing that a simple attenuator cannot fix.


Aside from the excellent sound quality, the other thing you will notice is the lack of latency. This is really important when editing as you want the sound to be heard at the same time as the waveform is displayed on the screen. By comparison, many consumer grade cards have either that much latency that editing software either complains or suffers from jitter which can affect the timing of the output by as much as 0.1 seconds (nearly 2.5 frames). That little amount of timing may not sound much but is readily noticeable when you need to lip sync audio from a source other than your DV file.

The Echo natively supports 24 bit audio throughout and sampling rates of 32, 44.1 (CD audio), 48 (DAT/DV), 88.2 and 96 (DVD Audio) kHz with the drivers able to lock the sampling frequency at the predetermined rate. This significantly reduces the load on the CPU which would otherwise be wasted resampling the audio to (usually) the highest rate the card supports rather than the required rate for the output. The drivers support WDM Kernel streaming, ASIO, GSIF and CoreAudio which allows the card to work with most professional audio and video software. Macintosh OS X is also supported.

Virtual outputs

One of the more interesting features of this card is support for 8 virtual outputs (4 x stereo buses). Provided your software supports it, (for example Sony Vegas) you can send each audio bus to a separate virtual output and mix using the card?s DSP rather than the CPU through software. You can also run several audio applications simultaneously (for example Cakewalk and GigaStudio) each outputting to its own virtual output, provided that the output sample rates are the same across each application.

The supplied software bundle is poor and aside from Sony Acid 3 Express (which is already two versions out of date) it basically comprises demo and evaluation versions of Cool Edit Pro 2, (now Adobe Audition) Sound Forge 6, Sonar 2, dj and Project 5. If you are used to consumer grade cards you will also notice an absence of special effects, karaoke software, surround sound and other gizmos, but then again you are buying the Echo Indigo io for the amazing sound quality not for gaming or the software bundle.


Overall the card produces very high quality output even though it is provided via a stereo mini-jack. Recording quality is also good, although unbalanced inputs do lead to noise which detracts from the otherwise quiet converters built into the card. It does the job but if you are serious about recording, you would probably need an external card that supports a variety of inputs. Although some people have purchased this card to listen to audio from DVDs and CDs, if you wanted a card primarily to listen to MP3 and other compressed audio sources you would be better off with a consumer grade card that hides the audio defects. However, for mastering and video editing tasks, it is better that you hear what is wrong with your audio rather than your clients.

Value for money
Reader Rating0 Votes
Amazingly quiet output, very high resolution output and low latency making the card ideal for audio mastering and video editing tasks, 8 virtual outputs with on card mixing, real volume control to adjust headphone levels.
Lack of digital and unbalanced inputs, lack of digital and pro level (+4 dBV) outputs.