Digital DIY

Computers helped former BBC engineer Clive Williamson and his band Symbiosis through all the stages of CD production, right through to finished discs and artwork.

In the first of a two‑part series, he explains how he brought digital technology and traditional musicans together to create atmospheric ambient music.Digital technology has been at the heart of most home‑based and professional recording studios for about 10 years now, but only recently has it become feasible to carry out every stage of making an album with help from computers. In this two‑part article, I'll be looking at the way computer technology has helped our group Symbiosis improve the scope of our writing and the sound of our recordings, to master our own CDs, and even to create our sleeve artwork.

The long‑term potential of computers in music is enormous. They can offer creative freedom, ways to fine‑tune a performance and — eventually — financial savings too! But things don't always work as they should. The falling cost of hi‑tech equipment has brought many exciting tools into the price‑range of the average musician, but it can be a time‑consuming and frustrating business to learn how to use them. Hopefully, our experiences will be helpful to others planning to follow a similar route.

Analogue Days

When we began Symbiosis, we needed to record concert flute played by John Hackett; acoustic, electric, and STEPP guitars from Rick Bolton; and my own voice, ethnic flutes, and hand percussion. Much of what we do is 'ambient' music in Eno's sense of the word — so our natural instruments were blended with atmospheric soundscapes and sampled percussion from synths. Our modest studio underwent rapid growth as I learned about MIDI. We moved quickly from a borrowed Tascam Porta 2 4‑track cassette to a Fostex M80 8‑track linked via a SMPTE timecode stripe and a synchronising unit to an Atari 1040 STFM computer system running C‑Lab's Notator sequencing software. Pieces were mastered onto a Revox A77 via a Seck 18:8:2 desk, and as the synth and digital effects collection grew, we bolted on an Alesis 1622 mixer for extra inputs.

After our first two albums, we moved to digital mastering on a number of portable DAT recorders, before finally settling on a Sony DTC1000ES modified for 44.1kHz operation. This DAT recorder also served to back up early experiments on Digidesign's Sound Tools system on a Mac IIcx.

Live instruments have always been a vital part of our sound, and although the M80 multitrack recorded acoustic and electric guitars well, and could manage the odd fretless bass, it really struggled with wind instruments like flutes, oboe and cor anglais. The sustained, pure waveforms of these instruments, which contain hardly any harmonics, often triggered an uncomfortable low grinding noise called bias bubble, and this was especially problematic in our gentlest, most ambient work, so I began to look for digital alternatives. As an interim measure, we improvised direct to DAT, editing the recordings in Sound Designer II on the Mac, then adding effects at the mixdown stage. But we soon tired of playing solos and duets, and it was then that the Alesis ADAT system came along and saved the day!

The Move To Digital

ADAT was a major turning point. Here at last were perfect drop‑ins, longer recording times, the possibility of making digital clones as backups or for alternative takes, and great sound. ADAT's clean recordings were a real joy, but soon began to highlight weak areas in studio acoustics and monitoring, revealing with perfect fidelity all the hiss, thumps, breathing, rumble and ambient noise that had previously been masked by the relatively high noise floor and distortions of analogue tape. To get around these problems, we had to make do with careful microphone placement, closing the double glazing, disconnecting the phone, and never recording during the rush hour, or when Concorde was due to fly over!

The most immediate effect of introducing the ADAT was to make me much more aware of the sound quality of the other components in the recording chain. Fortunately our mics were well up to the task: an old AKG C414 EB still sounded great on acoustic guitar and voice; and a newer C460 with a hypercardioid capsule was clean and noise‑free for recording a full flute sound without too much of the room's acoustics. The Seck and Alesis mixers had minimal EQ, but perfectly acceptable sound quality. The weakest links turned out to be:

• The sound of the recording room.
• Our monitor speakers (an old pair of IMF ALS 40s).
• High‑frequency losses in a long loom between the Seck mixer and the ADAT.

My engineering method in the Symbiosis studio has always been to record the instruments as cleanly as possible, and then add reverb later, using units like the Alesis Microverb II and Quadraverb. The ADAT recordings made it clear that there were far too many HF reflections in our 13‑foot square room, colouring the sounds of some natural instruments before they even reached the digital effects. I placed an order for some acoustic tiles, and we velcro'd these around all the available wall space to reduce high‑frequency ringing and spurious reflections.

Studio monitoring was also improved by the addition of the foam tiles, but I felt we could go further. After many listening tests, we purchased a pair of the Professional Monitor Company's AB1 loudspeakers. Mixes on these speakers seem to sound superb on most other equipment; after the ADAT, they are definitely the best things we've bought for the studio. Room acoustics and speakers dealt with, that just left the loom problems to be sorted out.

Making The Right Connections

One of the most exciting developments in music technology in recent months has been the shift towards fully digital mixing desks, led by the Yamaha 02R, but I realised that we couldn't possibly justify buying one, so I started to look for cheaper ways to maintain recording quality. Going digital as early as possible in the recording chain seemed to be the order of the day. The release of the Alesis Q2 reverb provided the perfect answer, and solved our loom problems at the same time.

Besides offering really clean reverb and effects, Q2 was designed from the start to link in digitally with the ADAT. Our current recording setup (see Figure 1) uses hi‑fi cables (kept as short as possible) between the Seck 18:8:2's Track 1 and 2 outputs and the Q2, and a direct optical link from the Q2 to the ADAT. Once the recorder is switched to Digital In, the Q2 in bypass mode (Preset 99) acts as a switching matrix to any two of the eight available tracks, and the analogue signal only has to travel down one metre of high‑quality cable!

Recordings made this way sound much sweeter and clearer at the top end, with the bonus that the Q2's settings can be edited to provide instant digital EQ on recordings. Used as a high‑pass filter, low‑frequency rumble can be rolled off before it gets to the ADAT, and much more precisely than with the low filters built into our AKG mics. The Q2 can also store a range of 'instant EQs' for any instrument regularly used by the group. Major equalisation changes are still left for the final mix, but the results going to tape are much more controlled. It's just a shame that the Q2 doesn't have any compression or peak limiting functions to prevent accidental clipping — but you can't have everything. Results through the mixing desk were further enhanced by throwing out our old 16‑way loom altogether, and making up short‑run good quality cables to get signals back from the ADAT's outputs to the desk.

ADAT To ADAT XT?

Another important reason for getting a Q2 reverb was its ability to act as a digital router for track‑bouncing on the ADAT without the greater expense of buying a BRC. The unit is relatively easy to use in this way with a single ADAT recorder, needing only a two‑way optical link to be established (see Figure 2). The ADAT must act as the clock source for the Q2, which is achieved by the following switching sequence:

• Set Q2 to Preset 99 'Bypass' and make sure the direct signal is ON (Global menu);
• Set ADAT clock source to Internal;
• Set ADAT to Digital In;
• Alter Q2 to Optical Input and optical clock source (Global menu);
• Select incoming and outgoing tracks for ADAT on Q2 (Global Menu);
• Prime 'record ready' on the relevant tracks, and check signal.

Once this is done, you can bounce signals from track to track cleanly, one or two at a time. You can also select any Q2 patch to add EQ, effects, or delay during the bounce. It's important to know that the Q2's meters only display anything sourced from channels 1 and 2 when used this way, so it's best to look at the ADAT's input metering to check things are working properly. Anyone owning the newer ADAT XT won't be so interested in these features, but for the thousands of original ADAT users, the Q2 really is a sensible upgrade, especially as its A/D converters are better than those in the first‑generation ADATs, and match those of the XT, being 18‑bit and 128x oversampling.

Digital Building Blocks

After ADAT, we added an Alesis AI‑1 digital interface and sample rate converter to allow sound to be transferred digitally from any source, or moved between the 8‑track and Sound Designer II software via an Audiomedia II card on the Mac. This instantly gave us the freedom to improvise onto the ADAT, then edit two adjacent tracks in Sound Designer, pass them back digitally and use that as the starting point for new pieces. Used this way, Digidesign's software often reverts to its original function — that of sample editor — giving us the chance to alter pitch, edit, blend and even turn sound round without any quality loss. Interestingly, it has proved possible to use the AI‑1's sample rate conversion facility over a very wide range, and signals fed out of the Audiomedia II at a playback rate as low as 1kHz (a drop of over five octaves!) are still converted to 48kHz on the ADAT without any problems.

Audiomedia's co‑axial S/PDIF outputs have proved useful for interfacing directly with equipment such as DAT recorders and a Roland S760 sampler with the OP760/1 output board fitted, and also with another handy building block in the Symbiosis digital studio: a Cambridge Audio DAC Magic 1. This is actually a hi‑fi component offering a very good quality D/A converter at a reasonable price (under £200 from some outlets) with three switchable co‑axial inputs, one co‑axial digital output and line outputs from the D/As on both phonos and XLR sockets. We use DAC Magic as a digital signal router and listening point, saving lots of re‑plugging, and augmenting by two the existing four separate outputs from the excellent S760. One of the two extra digital outputs from the 760's I/O board is permanently plugged to a DAC Magic input, and the D/A outputs appear on two channels of the mixing desk (as shown in Figure 3).

The final elements in our digital studio are a JL Cooper SyncMaster (for synchronising the Mac to SMPTE timecode), a JL Cooper dataMASTER (which generates SMPTE from the ADAT without wasting a track to record it) and a Sony DTCA8 DAT machine, replacing our DTC1000ES. All our music is now mastered onto the A8 using its Super Bit Mapping option, which seems to impart a richer, 'firmer' quality to the work, and provides a much better sense of space at low listening levels. As we bought one of the first A8s in the country, even our supplier didn't know that the machine suffered from the dreaded SCMS (Serial Copy Management System), but copies can still be made via the digital inputs of Audiomedia or the AI‑1, both of which strip off the copy‑protection flag set in S/PDIF signals!

I should also mention that I've also upgraded the Mac IIcx to a PowerPC 8100/80 with a 1Gb AV hard drive to cope with digital image‑handling for album cover design, and we have recently obtained OSC's Deck II and Emagic's Logic Audio in the hope of further integrating MIDI recording with hard disk editing and mixing.

Creativity & The Digital Studio

Recording studios have always been places where things can go horribly wrong, and the more complex we make them — with MIDI and digital connections — the more frustrating the problems can become. We're trying to link pieces of equipment from so many different manufacturers to make them do something new and wonderful with sound, only to discover that often the system doesn't work as it should, and no‑one can tell us why! One major snag with today's technology is that it develops so fast that there is barely enough time to assimilate the possibilities offered and techniques required by one bit of gear before we have to move on to the next. The only answer seems to be to alternate technical 'learning and editing' sessions with creative 'writing and recording' ones, so that the frustrations of the former don't taint the exciting potential of the latter. Above all, we need to test equipment well before we buy it, and make sure that we can work easily and intuitively with it.

A word of caution on the subject of the potential offered by today's technology was once offered to me by Bob Moog: "Everybody has certain reservations about how easy it is now to make sounds, and put sounds together into something that appears to be music. But it's just as hard as it always was to make good music. One always has to remember where the garbage pail is."

Next month, Clive Williamson describes the processes of preparing a CD master, burning recordable CDs, and designing album sleeves for Symbiosis with the help of computers.