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ESI Pro ESP1010

PCI Audio Interface [PC] By Martin Walker
Published August 2005

ESI Pro ESP1010Photo: Mark Ewing

If you're on a tight budget, ESI's new PCI audio and MIDI interface gives you more ins and outs for less money. But how does it stack up sound-wise against its pricier competitors?

ESI Professional now market a wide range of audio interfaces that cover Firewire, PCI and USB formats. Their recent Julia soundcard (reviewed in SOS January 2005) and RomI/O MIDI interface have proved very popular, but ESI are probably best known for their budget Waveterminal and more upmarket Wami Rack ranges. The latest ESP1010 model being reviewed here falls into the Wami Rack category, and is described as a "high-quality 24-bit 10-in/10-out PCI audio and MIDI interface with 19-inch rackmountable breakout box".

As with most '1010' products, two of the inputs and outputs are of the digital S/PDIF variety (in this case a coaxial in and out with a duplicate optical output), leaving eight analogue inputs and outputs, which are all capable of both balanced and unbalanced operation. There are also two MIDI Ins and Outs. Since this area of the market is already rather crowded, it will be interesting to see how ESI manage to make their new offering stand out.

Let's Switch Again

The rack breakout box is certainly smart in its two-tone grey finish, and was robust enough for me to stand on it without worrying unduly. The line-level analogue inputs are split between the front and back panels, with four on each, but are otherwise identical, each having a TRS-wired balanced/unbalanced socket with -10dBV nominal sensitivity and 10kΩ impedance, allowing connection of most consumer-level signals. In addition, inputs one and two also have optional mic preamps with XLR sockets on the front panel, each with its own switch for optional +48 Volt phantom power, an unusual and welcome feature at this price. The bundled software control panel utility is used to switch between mic and line inputs.

The eight analogue outputs are all on the rear panel, again on TRS-wired sockets for balanced or unbalanced use, and again with a nominal -10dBV output level. Outputs seven and eight are also duplicated on two front-panel quarter-inch jack sockets. However, there's a novel twist — these outputs can also act as dual stereo headphone outputs. The supplied software utility can send the stereo signals from output channels 1/2 to both of these two front-panel sockets via a dedicated headphone amplifier designed for phones between 32 and 300 Ω. If you use this option, the rear-panel outputs 7 and 8 both then carry identical balanced versions of the channel 1 output, which isn't particularly useful, but having the choice of two balanced/unbalanced outputs or twin stereo headphone outputs on the front panel adds to the unit's flexibility.

The breakout box is completed by a rear-panel pair of MIDI In/Out sockets, a D-sub connector to attach the associated PCI interface card, and a socket so you can plug in a 9-12 Volt DC 300mA power supply. The latter is not included, and is only needed if you require the full +48 Volt phantom power for your particular microphones — if they can manage with +12 Volts, or you don't need phantom power at all, the entire unit can be parasitically powered from your PC.

The PCI interface card is attached to the breakout box with a heavy-duty two-metre-long umbilical cable, and also houses the remainder of the digital I/O, courtesy of a one-foot-long adaptor cable terminating in two phonos for coaxial digital S/PDIF in/out and two MIDI sockets for the other MIDI In and Out, plus a handy duplicate digital out in Toslink optical format on the card's backplate.

Overall, this is an unusual yet versatile arrangement of inputs and outputs at the price. Splitting the MIDI I/O between PCI card and rack unit will bother few people, and having four audio inputs on the four panel will suit those who are constantly plugging different input signals into their setup. As we'll see shortly, inputs 1 and 2 can provide higher sensitivity that would prove suitable for plugging in electric guitars (prime candidates for front-panel sockets), except that the input impedance is only 10kΩ, which means that doing so will result in high-frequency loss. Nevertheless, if you often find yourself cursing at having to ferret about behind a rack to plug in synths and other line-level signals during a recording session, this might be just the interface for you.

Donning my nit-picking hat, I'm not quite so convinced about the novel output switching arrangements, which effectively make the rear 7/8 outputs redundant in headphone mode. I would also have liked an indicator on the rack's front panel — there's absolutely nothing to show that it's either connected or powered up correctly — while some users may find the umbilical cable rather too short and inflexible (it's half an inch thick).

The ESP1010's analogue inputs are divided between the front and rear panels. The optional DC power supply is not included, and is only required if your microphones need the full  48V phantom power. The ESP1010's analogue inputs are divided between the front and rear panels. The optional DC power supply is not included, and is only required if your microphones need the full 48V phantom power. Photo: Mark Ewing

Driving Music

Drivers are supplied that support Windows 2000, Windows Server 2003 and XP, but as usual I downloaded the latest 1.12 version direct from the ESI Pro web site. I had no problems during the installation, which detected two devices in turn, and the ESP1010 Panel utility appeared on my taskbar correctly after I'd rebooted. ESI told me that they are currently working on Mac and 64-bit drivers, but no release date has yet been set.

The current drivers use ESI's own EWDM (Enhanced Windows Driver Model) technology, and support MME, WDM, GSIF, Direct Sound and ASIO 2.0. The 'enhanced' element is that these formats are integrated into a single driver that offers full multi-client support, so you can access the drivers simultaneously from any number of applications. This integration also lets you freely patch digital signals between the various driver input and output formats using ESI's Direct Wire technology, so you could, for example, record internally from Gigastudio (GSIF) to Sonar (WDM) or Cubase (ASIO), or from an MME-based application like Winamp directly into your sequencer.

Control Panel

The Panel utility has some similarities to the one supplied for ESI's Julia, but has had a graphic makeover, and this time spreads the controls over two pages. The Mixer Panel page houses a 36-bit digital mixer, where for each of the 10 inputs and 10 playback channels there are digital faders with a 120dB range, peak-reading meters, pan controls, and mute functions (activated by clicking on the dB readout box beneath the faders — even with the faders pulled fully down, you need to use these to completely remove a particular channel from the mix). Overall level is set in the Mix Out section by a further pair of digital faders with a stereo Link button, and monitored on stereo level meters.

The ESP1010 Panel utility provides versatile control over the eight analogue inputs, two mic preamps, eight analogue outputs, monitor mixing, and headphone switching options of the ESP1010. The ESP1010 Panel utility provides versatile control over the eight analogue inputs, two mic preamps, eight analogue outputs, monitor mixing, and headphone switching options of the ESP1010. Photo: Mark Ewing

Meanwhile, the Control Panel page devotes its left-hand side to inputs and its right to outputs. Inputs 3 to 8 simply have meters to monitor incoming levels, as does the digital S/PDIF input, along with an additional 'Locked' indicator that lights up if a suitable clock signal is detected. With a fixed input sensitivity of -10dBV, I found these inputs a good match for most of my hardware synths.

Analogue inputs 1 and 2 are more complex, and initially a little confusing. Each has two gain controls, the first a slider with a 60dB range operating in the analogue domain, and the second a rotary digital gain control offering up to 15dB of additional gain. The text readout at the bottom of each channel displays the combined gain value of these two controls, which can therefore range from -60dB to +15dB. There are also tiny buttons beneath each channel for switching between M(ic) and L(ine) use, which can be changed independently for each input.

In Line mode, and with the gain at 0dB, inputs 1 and 2 are identical in sensitivity to inputs 3 to 8, but when in Mic mode, an additional preamp is switched in. According to the manual you can't use the XLR and quarter-inch inputs simultaneously, but I found both are in fact still connected to the preamp in Mic mode, so you should be very careful not to leave line-level signals plugged in to the quarter-inch jack sockets when plugging a mic into the associated XLR socket.

The phantom power is also confusing. There's a tiny button labelled '12' next to each of the two Mic/Line switches in the Control Panel; these buttons are only operational in Mic mode, and activate +12 Volt phantom power. This will probably be sufficient in many situations, but may limit headroom. To activate +48 Volt phantom power you need to ignore these Control Panel switches, plug a DC power supply into the rear of the rackmount breakout box, and instead use its front-panel +48 Volt switches. As you might expect, it's not recommended to activate +12V and +48V phantom power simultaneously!

The Control Panel Output section contains digital level faders for each analogue output, once again with a 60dB range, and arranged in pairs with a stereo peak-reading meter alongside each one. The S/PDIF output has stereo meters but no faders, but there is a choice of Professional or Consumer formats via a pair of buttons above these meters.

Beneath the output 1/2 and S/PDIF Out meters are two buttons labelled Mix Out. Activating either or both of these removes the normal playback signal from these outputs and replaces it with the combined mix output from the Mixer Panel described earlier, which is handy if you want to monitor your inputs with 'zero' latency during the recording phase and simultaneously hear the outputs from your multitrack sequencer. Above output channels 7/8 is a further button labelled 'HP', which performs the unusual headphone switching described earlier. The Control Panel is completed by a small panel that lets you manually select sample rates if required, choose internal or external clock options, and view a readout of the current clock source and sample rate.

ESI Pro ESP1010 Brief Specifications

  • Sample rates: 22, 24, 32, 44.1, 48, 88.2, 96 kHz from internal clock (22 and 24 kHz not supported by digital I/O).
  • Mic preamps 1/2: up to +31dB additional gain, separately switchable +12V phantom power from PCI card, with +48V available from a suitable 9V DC power supply.
  • Analogue inputs: eight quarter-inch TRS balanced/unbalanced jack sockets with nominal -10dbV sensitivity (line inputs 1 and 2 have up to +15dB digital gain option).
  • Analogue outputs: eight balanced/unbalanced TRS quarter-inch jacks at fixed -10dBV level, plus two stereo headphone outputs.
  • Digital I/O: S/PDIF in and out on coaxial phono sockets, S/PDIF Toslink optical out, two MIDI Ins and Outs.
  • Dynamic range: input 107dBA at 48kHz, output 112dBA at 44.1kHz.
  • Frequency response: not stated.

In Action

With my now traditional double-blind listening tests, I auditioned the sound quality of the ESP1010 against my benchmark Emu 1820M and Echo Mia soundcards, using a wide of material including solo vocals, guitar, drums and percussion, plus rock band, dance music, jazz trio and classical orchestra.

As you might expect on this occasion, it was easy to pick out the more expensive Emu 1820M every time for its tight, focused sound — the other two cards provided high-quality sound and each instrument appeared in the right place, but with the Emu I felt I could almost reach out and touch them. As always, these were subtle but nevertheless noticeable differences, and while the other two interfaces were slightly different, they were very tricky to tell apart reliably. However, after a prolonged listening session I decided the ESP1010 had a slight edge over the Mia for its more natural top end. When the stereo Mia was first introduced it cost as much as the eight-channel ESP1010, so this is an excellent result for ESI's latest offering.

Running Rightmark's Audio Analyser roughly confirmed the manufacturer's quoted dynamic range figures: I measured 105dBA at 24-bit/44.1kHz, and an even better 107dBA at 24-bit/96kHz, which is unusual considering that at 96kHz the upper -0.1dB fall-off point increases from 20kHz to 43kHz — normally a wider bandwidth results in a higher noise level. The low-frequency -0.3dB points were at a good 9Hz and 13Hz respectively. Total harmonic distortion was a very good 0.0006 percent, while stereo crosstalk was also good at about -106dB. Overall these are a very good set of figures for this price, and taken in conjunction with my subjective auditions, I feel that ESI have done an excellent job.

On the driver side, with my Pentium 4 2.8GHz Northwood PC I managed to drop the ASIO 2.0 latency down to 128 samples at 44.1kHz without any glitching in Cubase SX3, resulting in a low latency of just 2.9ms. I had absolutely no problems running the GSIF drivers with Gigastudio, while the Direct Sound and MME drivers proved to be fairly similar to most under I've tried under Windows XP, respectively achieving 35ms and 45ms Play Ahead settings with NI's Pro 53 soft synth.

Summing Up

Although there are plenty of variations on the 'eight-in/eight-out analogue plus S/PDIF and MIDI' specification already in the market, when I started to look for competitors for the ESP1010 I began to appreciate just what incredible value it actually is. Edirol's UA101 and FA101, Guillemot's Hercules 1612FW and M-Audio's Firewire 1814 are all around the £400 mark, and even the budget Terratec Phase 88 Rack FW that I reviewed in SOS May 2005 is £360, which I described as an excellent retail price.

ESI Pro's ESP1010 may have a few design quirks, but its audio and driver performance are excellent, and it incorporates several clever twists such as the mono line/stereo headphone outputs on the front panel. It doesn't interface with the more professional +4dBu I/O levels, and nor does it have 192kHz support, but I personally know of no musicians actually using this sample rate in the real world, and even at the suggested retail price of just £249 it's excellent value for money. On the street I've seen it priced as low as £211, and I can think of no other rackmount eight-in/eight-out interface anywhere near that price. If you like a bargain, the ESP1010 will be right up your street.


  • Superb value for an audio interface with two mic preamps and fully balanced eight-in/eight-out analogue capability.
  • Includes a digital monitoring mixer and twin headphone amplifiers.


  • Bulky umbilical cable.
  • No power indicator on rackmount breakout box.


ESI have managed the impossible with the ESP1010. Never before have I reviewed an audio interface containing so many features, and with such a good sound, for so little money.


£249 including VAT.

Electrovision +44 (0)1744 745000.

+44 (0)1744 745001.