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Terratec Audiosystem EWS64

XL PC Soundcard By Martin Walker
Published March 1998

Terratec Audiosystem EWS64

With a feature list longer than most people's arms, the EWS64 XL has whetted plenty of appetites. Martin Walker dismantles his PC once again in the search for the ultimate soundcard.

There has been a lot of interest in the Terratec Audiosystem EWS64 XL — indeed, SOS has had more queries about the possibility of a review than for any other soundcard. It's not hard to see why. The EWS64's biggest carrot is its "studio quality" sampler, with up to 64‑note polyphony, 6Mb of RAM (expandable to a huge 64Mb), 16‑note multitimbrality, 24dB/octave filters, three envelope generatorsand two LFOs per voice, plus many of the performance features you'd expect to find in a rack unit. It also has a switched optical/coaxial digital input, two digital outs, two MIDI Ins, and two MIDI Outs, plus enough DSP power to mix up to 64 stereo digital signals, and an updatable operating system for adding more features at a later date. It's hardly surprising that people are frothing at the mouth.

With such an ambitious spec, teething troubles were almost inevitable, and the initial batch of drivers for the EWS64 (version 1.3) caused headaches for people who bought when the card was originally launched in August 1997. On top of this, the sampler functions remained unavailable and were promised in the next software release. Version 2.00 drivers (available since before Christmas) have solved initial installation problems, but the sampler functions are still absent at the time of review, although they are promised by the time you read this. Naturally, we'll update you as soon as we've seen the sampler in action.


The EWS64 XL has so many functions that the block diagram initially looks extremely complex, since there seems to be two of almost everything. Luckily, the help file allows you to click on each block for a full description of its function.The EWS64 XL has so many functions that the block diagram initially looks extremely complex, since there seems to be two of almost everything. Luckily, the help file allows you to click on each block for a full description of its function.

The EWS64 XL is a 16‑bit ISA buss card which, at only about nine inches long, should present few physical installation problems. The origins of the card are in the games world, and it supports a large list of formats, such as SoundBlaster, SoundBlaster Pro and Adlib, as well as several MOD/Tracker sample formats (originally derived from the Amiga computer). One thing that has confused some people is that, due to the card's extensive compatibility with game sound formats, it often presents two ways of doing the same thing — one through the high‑quality 18‑bit A/D and D/A converters, which offer up to 48kHz sampling rates, and the other using the all‑in‑one Crystal CS4236B chip (which contains the SoundBlaster‑compatible 16‑bit A/D and D/A converters, and one of the MIDI interfaces). As you can see from the signal‑path block diagram (below), there's an awful lot crammed onto this board. The functions of the upper half (16‑bit A/D, D/A, FM synth, analogue mixer) are largely consumer quality, and not really ideal for the PC musician in search of high‑quality audio. It's the lower section of the board that's of most interest to us, since this is where the synth and the 18‑bit converters are found.

The synth section itself is responsible for MIDI, Wave, and MOD processing, as well as audio effects (there's also WAV recording and playback functions at lower quality for game support). The synth/sampler component offers up to 64 voices, which emerge from Output 1 (with or without effects), while the Wave device handles up to 64 audio streams for hard disk recording and playback, and can be routed either to Output 2 or, via the effects, to Output 1. Extended full duplex is supported, and this allows recording of a single stereo input with simultaneous playback of up to eight WAV files. This is achieved in hardware, and so will use far less processor overhead than relying on software to mix multiple tracks to the same stereo output format. The MOD device deals with hardware support of Tracker files (again, a nod in the direction of the games fraternity). The effects consist of chorus (including flange and delay options), reverb, and V‑space, a proprietary 3D algorithm for playback through either two or four channels.

On the audio side, the card has 2Mb of RAM permanently on board and comes with an additional 4Mb RAM card, giving you 6Mb straight from the box. You can expand this memory by discarding the 4Mb module, and plugging in one of a selection of other 72‑pin types — a single‑sided 8Mb SIMM, or standard 16Mb or 64Mb modules (but not 32Mb) with a speed of 60nS or better. I suspect that some people will want to expand straight away, and will be a bit miffed at having to immediately remove 4Mb, but it's not that much of a hardship, since 4Mb of RAM is now worth under £20. The operating system and the reverb and chorus use a small amount of RAM, so if you stick with the 6Mb of RAM supplied you'll be left with about 5Mb for your own sounds (or GM/GS soundsets).

Not content with filling the soundcard with features, Terratec also provide a 5.25‑inch removable plug‑in module, which attaches to the soundcard with two ribbon cables. This is designed to sit neatly in a spare drive bay in your PC, exactly like an internal CD‑ROM drive, so that the extra facilities can be easily accessed from the front of the PC. On this panel are the two MIDI Ins and two MIDI Outs, and the digital I/O. The MIDI 1 set of sockets is connected to the internal synth, and MIDI 2 to the WaveBlaster (daughterboard) socket also found in the module. You can also use the joystick socket mounted on the soundcard itself as a MIDI In/Out, by diverting either MIDI 1 or 2 using a software switch in the supplied EWS Control Panel software; you'd then also need one of the standard conversion leads used by many other soundcards. There is a single S/PDIF input, but both optical and coaxial sockets are provided (selected, again, by using a software switch in EWS Control Panel). The two digital outputs can be used simultaneously, and each is connected to one of the two 18‑bit D/A converters (although there are a variety of possible routings, normally the MIDI synth will appear on Digi 1, and the WAV file playback on Digi 2). The module also features a standard quarter‑inch stereo headphone socket.

The driver and utility software supplied for review was an interim version, but by the time you read this a new CD‑ROM version of the version 2.0 software will be available, with fully updated English help files.


The EWS64 Control Panel certainly looks suitably hi‑tech, and provides access to every possible knob and switch required. It would not, however, win any awards for ergonomics, and makes it rather difficult to follow the signal routing possibilities (the help file provides full details of the cryptic switching arrangements).The EWS64 Control Panel certainly looks suitably hi‑tech, and provides access to every possible knob and switch required. It would not, however, win any awards for ergonomics, and makes it rather difficult to follow the signal routing possibilities (the help file provides full details of the cryptic switching arrangements).

Whenever I receive a 'full‑featured' soundcard I take a deep breath, since they tend to use a lot of system resources, and this one is no exception. The manual states that, with all functions enabled, three IRQs, two DMAs, and nine I/O addresses are used. I brewed a flask full of strong black coffee and then read the manual through before I did anything else. If it's Plug and Play (as this one is), a soundcard can be simplicity itself to install, but with this many settings being managed by Plug and Play, if you have any legacy (pre‑Plug and Play) devices in your PC you could be in for problems. Sure enough, after I had inserted the EWS64 XL and re‑booted, my machine got partway through the install procedure, and then popped up "The CS4236 Codec was not found at the expected I/O address". When I clicked on 'OK' my PC crashed. This seemed a sure sign that Plug and Play had allocated one of the I/O addresses by default to a value already used by a legacy card (it has no idea what resources are used by these).

To find out what was causing the problem, I performed a cold boot, by pressing the hardware reset button on the front panel of the PC, then pressing the F8 key at the appropriate time during the re‑boot, to bring up the Windows 95 Startup Menu (see the May '97 issue of SOS for my guide to PC Crash Recovery). From here I selected 'Safe Mode', which boots up into a minimal environment, and which excludes the majority of drivers (including the new Terratec ones that were causing the problem). Once inside Device Manager (from Control Panel, System), I could see what the problem was. Sure enough, the Terratec EWS64 XL Codec (the all‑in‑one consumer Coding‑Decoding chip) entry showed in its Resources section that it was pointing at address 220h, which was also being used by my ancient Sound Galaxy soundcard. By un‑ticking the 'Use Automatic Settings' box, I could then manually change this entry to 240h, which I knew was not in use. This is the huge irony of Plug and Play — if you still have any legacy devices, it's sometimes more trouble to work round it than if you had jumpers on the new card to set things up in the first place.

After I had restarted the PC, the next boot correctly installed the remaining drivers, and I emerged triumphantly into my normal desktop environment with everything functioning properly. You're unlikely to run into this problem unless you already have another soundcard in your PC with SoundBlaster support, but my experience does show how to proceed if anything goes amiss. Fortunately the software and hardware documentation are comprehensive and thorough as well.

Audition Time

Terratec Audiosystem EWS64

Once everything was working, I sat back to listen to the audio performance of the card, using a wide variety of MIDI files. The CD‑ROM provided four sound banks — both GM and GS in 1Mb and 4Mb sizes. I loaded up the 4Mb GM set first, and the sounds were good, quiet and clean, although a little bland, but those of the 4Mb GS set were noticeably better, in particular the Grand Piano, which was far more rich and responsive. Both sets still came second to those of the Yamaha DB50XG daughterboard (the standard by which others tend to be judged), but this, of course, will be academic once full sampler support is available and users can fill up whatever RAM they have with their own sounds.

Of the effects (controlled from another utility), the Chorus worked well, adding life and movement to the sounds, and the 4‑band (or 2‑band) EQ was great for beefing up the overall mix. However, the reverb was decidedly metallic, and is better placed well down in the mix, or replaced by an external reverb. It might be possible to improve this with a future software update.

The internal synth is connected to MIDI 1, and as if acknowledging the huge number of resources taken by this card if everything is activated, MIDI 2 is de‑activated by default (it takes yet another interrupt and I/O address). If you want to use the second MIDI In and Out on the module for attaching external MIDI synths, or to add a WaveBlaster‑compatible daughterboard, you'll need to activate it first. This is done by deleting the MIDI 2 driver inside the Device Manager and restarting Windows, which then 'finds' the new hardware and activates the MIDI 2 driver. It's also possible to access the Wavetable synth without using yet another interrupt, but you do lose the facility of the MIDI 2 input.

On the audio side, I started by recording into input 1, and routing it through the Codec. Once I'd worked out which of the switch positions I needed on the EWS Control Panel, and selected the 'EWS64XL Codec Record' and 'EWS64XL Codec Play' drivers in Sound Forge, I tried some basic recording.

This is a 'consumer' chip, and cannot compete in the quality stakes with the other converters. Anyone who expects to use the two A/D analogue inputs simultaneously may be disappointed with the results. Sure enough, the unweighted RMS background noise was about ‑70dB (with peaks up to ‑55dB), which, while good enough for basic demos, is not really suitable for serious music work. Next I tried the same procedure using the rather better 18‑bit A/D converter, routing through input 2, which also bypasses the analogue input mixer for an even cleaner signal path. I found that background noise levels were much lower (as I expected), measuring ‑89dB RMS (highest peak ‑76dB). Of the 10 soundcards I have tested to date, this excellent noise result is on a par with that measured for the Digidesign Audiomedia III, and is only bettered by the Event Gina, which measured ‑92dB RMS (‑84dB peak). It's safe to say that Terratec have not misused the word 'professional' in connection with the EWS64 XL.

I did find the EWS Control Panel confusing, due to the number of different audio paths available, since labelling switch positions as 'A, B, and C' doesn't give you much idea what they do without constantly delving into the helpfile. I lost MIDI control of the synth for a while, until I realised that a switch on the EWS Control Panel had been changed, disconnecting the MIDI Input on the joystick adapter cable and re‑routing it to the module MIDI sockets. However, once you get the appropriate signals coming out of the desired outputs and everything routed properly, it all starts to fall into place.

Once you look at the parts of this card specifically designed for musicians, the audio quality shines through.


The FX Panel is easier to follow, and makes tweaking relatively painless. The 4‑band equaliser is particularly well implemented, with click and drag points on the graph.The FX Panel is easier to follow, and makes tweaking relatively painless. The 4‑band equaliser is particularly well implemented, with click and drag points on the graph.

The EWS64 XL is a truly ambitious product, and it's not surprising that there has been so much interest in it. Anyone who vaguely remembers compatibility with Akai samples being mentioned is not mistaken — Terratec are currently looking into the possibility of offering sample‑loading direct from Akai‑format CD‑ ROM. However, it is this 'vapourware' aspect of the card that will disappoint many people. As I write this review halfway through January (five months after the original release of the card in August 1997) Terratec are still working on the Ed!son (sic) Instrument Editor, which will give full access to the card's sampling functions. It's always difficult to establish exactly how long software development will take, and there have been unforeseen problems, but the Beta version is promised by the time you read this, as are several other utilities to allow users to create their own sample sets. Apparently Terratec have a close relationship with Steinberg (Cubasis AV is bundled with the card) and because of this, ASIO drivers for Cubase VST are also in an advanced state of development. A stereo driver is expected to be released before you read this, with a multi‑channel version promised by the end of February. If all this happens, and Terratec UK are confident that it will, the EWS64 XL can definitely be recommended. However, it's not surprising that people who have already bought the card have been rather frustrated.

The EWS64 XL will suit those who want a good quality soundcard for audio and MIDI recording, and digital I/O, along with support for the occasional game. Its confusing aspects derive mainly from its game support, because although basic SoundBlaster support is vital for any card which is to be sold to games players, this support gives rise to a huge list of extra features and a convoluted signal path. However, once you look at the parts of the card specifically designed for musicians, the audio quality shines through, and the EWS64 XL should suit many people who want an all‑round card for serious music use, as well as the odd game. Ultimately, if you want a single card that will do virtually everything, at the price there's not a lot of competition. A cautious thumbs‑up.

Brief Feature List

This is what everyone is still waiting for — the Ed!son editor for the EWS64's sampler. This is its front panel, as shown in the software help file. The full version is expected, at the latest, by the beginning of March.This is what everyone is still waiting for — the Ed!son editor for the EWS64's sampler. This is its front panel, as shown in the software help file. The full version is expected, at the latest, by the beginning of March.
  • Wavetable Synth/Sampler: 6Mb RAM supplied, expandable to 64Mb.
  • Up to 64‑voice polyphony.
  • Sampler features (not available in review model): 24dB/octave filter, 3 EGs, 2 LFOs per voice.
  • Effects: Reverb, Chorus, 4‑band and 2‑band EQ, 3D sound positioning. Available for all audio sources.
  • Mic In: Wired for stereo mic (electret or dynamic). No phantom power.
  • Line In 1: 8/16‑bit consumer A/D, 5kHz‑48kHz sampling rate.
  • Line In 2: 18‑bit high‑quality A/D, 32/44.1/48kHz sampling rate.
  • Line Outs: 2, both driven from separate 18‑bit D/A converters.
  • Audio Recording: Simultaneous, extended full‑duplex recording (stereo) and playback of up to 8 stereo channels, internally mixed down to a single stereo output.
  • S/PDIF digital I/O: optical or coaxial in, two coaxial outs.
  • MPU401‑compatible MIDI I/O: 2 external Ins, 2 external Outs (one connected to internal synth, other to WaveBlaster daughterboard socket).

Slot Machine

The synthesizer chip within the EWS64 XL contains 'virtual' devices, and since the operating system is supplied on an EEPROM (Electrically Erasable Programmable ROM), updates can be provided in the future as software downloads, to add new features and cure any bugs. The core of this chip is responsible for controlling MIDI sample playback and hard disk audio playback channels, as well as the effects and filters, and contains 64 processor 'slots' or 'units'. Playing back a MIDI sound requires the use of a single slot (and sometimes two), as does a hard disk audio channel. The Chorus effect takes three slots, the Reverb 13, and the 4‑band equaliser eight. Since there are 64 slots in total, the maximum number of notes available at any time will depend on what other facilities are being used. Other restrictions are due to the ISA buss, which can theoretically achieve playback of up to 17 stereo WAV files at 44.1kHz. However, Terratec say that in practice you may manage a maximum of about eight stereo audio channels, or 14 mono ones, using the hardware mixing capabilities of the soundcard. This, of course, also depends on your hard disk recording software.


  • Clean, quiet 18‑bit signal path.
  • Digital I/O.
  • Onboard capability for 64‑voice sampler with filters.


  • Sampling options still not supported by software.
  • Initially confusing signal path.
  • Uses a lot of PC resources with all functions enabled.
  • Poor quality reverb.


A comprehensive and capable soundcard with a very good audio spec where it counts, and the benefits of digital I/O. The EWS64 XL has been hampered by late delivery of the sampler software (still not available at the time of review), but once this appears it will be a card to be reckoned with.