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PC Desktop Music Systems — How To Connect Them

Tips & Tricks By Paul White
Published November 1996

Paul White looks at the components of a PC‑based desktop music system, and suggests some helpful ways of using such setups in conjunction with more 'traditional' studio equipment.

A 'traditional' modern project music studio is a complex and costly affair, comprising MIDI sequencers, sound modules, keyboards, outboard effects, multitrack recorders, mixers, miles of cable — you're an SOS reader, you know the story. But while some studio owners have been extending their garages so they can fit in yet another rack of processors and some bigger monitors, a quiet revolution has been taking place on the desktop studio front. Most of you will at least have heard of the MIDI + Audio sequencers that run on an Apple Macintosh or IBM‑compatible PC, but of the users I've spoken to, most use such programs within the context of a more orthodox recording setup and tend to drive external sound modules or samplers. On the other hand, we all know about soundcards. Cheap, compact and now capable of supporting basic direct‑to‑disk audio recording and playback, they're the things you plug into PCs to make games sound marginally less dull — but they can't be taken seriously if your aim is producing professional‑sounding music recordings.

A couple of years ago, this last (admittedly facetious) statement might have gone unchallenged, at least as far as affordable hardware was concerned, but over the past few months, some very serious musical hardware has turned up on PC soundcards, much of it derived from existing keyboard instruments, or sound modules costing three or four times as much. The humble AWE32 SoundBlaster and its contemporaries offer a lot of possibilities, considering their very low price, but if you're prepared to spend between £150 and £250 on a wavetable‑based synth card, you can now expect quality that rivals that of a stand‑alone synth. What's more, because PC cards are purely software‑driven, you often find a surprising amount of useful support software bundled with the card, including sequencers, editor/librarians, MIDI song files, mixer maps for the most commonly used sequencers and even Karaoke software. Sadly, there's little sign of any on‑line psychiatric support, which is probably the only thing that could benefit those unfortunate souls who believe that booting up the MIDI Karaoke bar constitutes a good idea!

Because PCs have a number of expansion slots, it's quite possible to use two or more soundcards in the same machine, though installing PC hardware isn't always the painless procedure it ought to be, as will be explained in a future SOS article. If you're using Windows 95, then choosing a 'Plug and Play'‑compatible card should help simplify things. However, unlike typical all‑in‑one MIDI + Audio multimedia cards, some dedicated synth cards (such as the Yamaha SW60XG) install in the PC's short slots, and require no fiddling about with IRQs or DMAs. If you are as yet blissfully ignorant of these seemingly‑innocuous initials, know now that they can strike terror into the hearts of even seasoned PC veterans, but again, we have plans to demystify the subject (or at least let you know why you have every right to remain mystified!) in a forthcoming detailed article. For a quick explanation, check out the feature starting on page 164.

Suffice it to say that even a modest card can provide you with a very nice GM synth, complete with effects — and possibly a sing‑along Karaoke mic input with reverb! What's more, cards have their own stereo output jacks, their sounds and effects can normally be edited via software, and they don't need a physical MIDI interface to drive them (most cards come up in your sequencer as a 'virtual' MIDI port). For more on soundcards, see Brian Heywood's detailed article on the subject starting on page 180 of this issue.

Making Connections

The main reason for this appetite‑whetting preamble is to show you that while a cheap soundcard plugged into a pair of tiny powered AV monitors isn't going to threaten the conventional studio, for very little additional expense, the more serious PC‑based user can gain access to some pretty impressive music power. What's more, it's often possible to mix and process the sounds in a far more comprehensive way than you might imagine. For example, there may be several separate stereo outputs, that can be conventionally mixed, coming from different soundcards and daughter boards. While there's usually an option to daisy‑chain the audio ins and outs of various soundcards to enable you to mix everything to stereo, the quality penalty is significant (see the separate 'Board Room' box for more on this). By keeping your outputs separate, you can patch into an external mixer, which is obviously far more flexible.

Even if you only have two sets of stereo outputs to play with, a separate mixer will allow you to create up to four separate groups of sounds (by using MIDI panning to move sounds hard left or right) after which you can independently EQ and effect each group of sounds as required. Monitoring can be via a proper system or hi‑fi, rather than cheap, powered desktop speakers, and the improved audio quality of an external mixer means you can end up with a very respectable‑sounding mix, especially if you master to something like DAT or DCC rather than analogue cassette.

There are other reasons for using an external mixer. Although soundcards often come with mic or line inputs that allow you to record your own .WAV audio files, the signal path through these is usually pretty grotty (as are the mics that interface with them). What's more, as well as being built to a price, budget soundcards have to work inside the PC, where there's potential for high‑gain mic inputs to pick up lots of interference from the various data busses. A far better option is to use an external mixer to bring the output from a decent mic up to line level, then feed this into the soundcard's line‑level input. Not only does this give you the chance to use a studio‑quality mic, it will also improve the signal‑to‑noise ratio of the recording by amplifying the signal within the mixer rather than within the soundcard.

Even using a budget 'something into two' general‑purpose mixer, you can use one channel as a mic preamp simply by turning the channel fader right down and using the channel insert send to feed your soundcard. The mic gain is set using the channel gain trim, and the signal level can be monitored using whatever facilities are provided with the soundcard. Figure 1 shows how a typical multi‑card PC system might be connected.

If you have a mixer with no insert points, you can instead use the pre‑fade aux send on the mic channel to send the mic signal to the correspondingly‑numbered aux send output, then use this to feed the soundcard input. For example, you could feed your mic into channel 1, then route this to the aux 1 output by turning up the aux 1 send on channel 1 only. The level fader on channel 1 should be off, and the level sent to the soundcard will then be controlled by the aux 1 master output level knob. You can still connect outboard effects to the mixer in the conventional way, via post‑fade aux sends and effects return channels.

Some soundcards allow you to feed in an external audio signal, to which the card's own internal effects may be added — very useful if you can't afford a separate effects processor. In this case, you can connect the audio input of the card to a post‑fade effects send and treat it much like an external effects unit, the main difference being that the effect comes back mixed with anything else that's coming out of the soundcard, rather than separately, as would be the case with an outboard effects box. The software supplied with your card should be used to set the dry/effects mix to 100% effects, and the effects sends should be turned right down on the mixer channels the card is plugged into, otherwise you'll be sending the effected output back into the card again, and feedback will result.

How flexible this approach is depends on the type of soundcard you have. I've a sneaking suspicion that audio inputs are provided mainly to satisfy the Far Eastern market who demand that the cards double as MIDI Karaoke systems! Even so, it's a very welcome facility to have thrown in at no extra cost.

And There's MIDI

A basic PC MIDI music system will generally make use of the MIDI interface provided by the soundcard; the standard way of working is to use a MIDI adaptor cable that plugs into the card's joystick port. Alternatively, you can buy a hardware adaptor that looks like a long multi‑pin plug with MIDI sockets built into it. These often allow you to leave your joystick connected via a Joystick Thru socket, but I'm informed that some MIDI programs get upset if a joystick is left connected, so if in doubt, unplug it.

The limitation of a simple '1‑in, 1‑out' MIDI interface is that you can only drive 16 external MIDI channels. With today's synth modules, that usually means a single multitimbral instrument, but remember that internal soundcards, other than daughter boards, use virtual MIDI ports. This is obviously good news if you're on a budget, as you can use your internal soundcard sounds at the same time as your external MIDI module, and you still only need one MIDI port.

If you need more ports to handle additional external synths, then you can buy so‑called multi‑port MIDI interfaces, either as cards or external hardware boxes, offering two, four or eight sets of MIDI outputs. These should not be confused with simple multi‑output Thru boxes, where each MIDI Out carries the same information — a multi‑port interface's outputs are quite independent, and tend to be identified by number or by letter. For example, port A would carry MIDI channels 1A to 16A, while port B would carry channels 1B to 16B, and so on. An 8‑output multi‑port interface provides 128 separately‑addressable MIDI channels, which is sufficient for all but the most gear‑intensive setups.

A 'dumb' MIDI master keyboard can simply be connected to the MIDI In, while a MIDI synth would need to be set to Local Off, so that the synth section could be driven from the MIDI Out port of the computer (Figure 1 shows the latter option).


A PC‑based MIDI/.WAV audio studio has the advantages of being inexpensive, compact and (once set up) convenient. With the addition of an external hardware mixer, a monitoring system, and possibly some outboard signal processing, you have the basis of a serious desktop music recording system, and as soundcards continue to become more powerful and better specified, you can upgrade your system a piece at a time without having to sell up and start from scratch. Those interested in direct‑to‑disk recording will find that some of the mid‑priced cards, such as those built by Turtle Beach, are well worth investigating. Alternatively, a separate audio card, such as Digidesign's Audiomedia III, is capable of excellent results, and has the advantage that it keeps your audio and synth signals separate, rather than mixing them as a budget 'all‑in‑one' card would.

I think the 'traditional' studio will be with us for very many years to come, but as the capabilities of PC‑based systems continue to increase, the boundaries between the two types are bound to become blurred. By choosing your cards carefully, and by incorporating a small mixer plus a modest amount of external signal processing, you can build a serious desktop studio for less than you might once have paid for a stereo sampler.

Card Conflicts: Problems Installing A Second Card

If you install a second card that requires MIDI, such as Yamaha's SW60XG, you may need to change the MIDI port address the new card will use, because if you already have a card installed in the PC, the chances are that it will already have hogged the internal MIDI port on the PC that the new card is expected to work on. Sorting this out is a matter of moving plastic jumper plugs on the card to an unused MIDI port number, and then entering the same number in the software driver's settings dialogue box. If this seems confusing, don't panic, just stay tuned — this kind of potential complication will be covered in detail in a future SOS article.

Look, No Hardware: Software Synthesis

Software‑based synthesis (which uses the computer's own processing power rather than hardware to create sounds) is becoming more practical now that high‑powered computers are relatively cheap. Obviously, these packages use up some of the computer's processing power and memory, and depending on how sophisticated (and well‑written) the software is, this amount can be anything from just a few percent up to nearly the entire processing power of the system, with consequent limitations on what you can run alongside the software synth.

At the budget end of the market, software synths can rival cheap soundcards for sound quality, and they tend to be GM‑compatible, but their main application is in the games market. My recommendation would be to to stick with hardware cards wherever possible, unless you come across a software synthesis package offering you creative potential that doesn't exist elsewhere in your system. Then again, the future could change all this!

Board Room: Daughter Boards

If you're stuck for space in your PC, you can piggy‑back a 'daughter board', such as Yamaha's DB50XG, onto any of the more common soundcards that come fitted with a suitable expansion connector. I only mention this specific card because I have one strapped to my AWE32, where it responds to any MIDI data sent to the AWE32's external MIDI output. However, if you're already using the external MIDI output for something else, you'll have two instruments playing at once, unless you switch one of them off.

A disadvantage of such daughter boards is that their high‑quality audio output is fed through the audio stage of the main soundcard, in order to mix it with any sounds you may be using from the soundcard's other synths or audio playback system. The usual outcome is a noticeable loss of sound quality (especially increased noise), and of course the fact that the signal from the daughter board emerges at the main soundcard's output means that you can't separately process the daughter board's signal.

If you're handy with a soldering iron, it's usually possible to intercept the daughter board's output and feed it directly to the outside world via fixed audio cables or mini‑jacks fixed to a spare card slot cover (once again, a forthcoming feature will explain how to carry out this operation on Yamaha's DB50XG daughter board). Because of the large number of high‑quality soundcards appearing on the market, it isn't possible for us to provide mod details for all of them, but it's worth contacting the manufacturer's own tech support people first, then scouring on‑line Internet resources if that doesn't bring a result.