You've blown all your money on an 8-track recorder and you've only a few hundred left for a mixer. No doubt you'd like an 8-buss console with in-line monitoring and MIDI muting — but you might be surprised to find that you can produce high quality recordings using a standard stereo mixer. Paul White shows you how.

This article was inspired by a reader's letter we received recently, asking how a stereo mixer could be used for multitrack recording. Certainly a stereo mixer is less than ideal, but back in my open-reel 4-track days, I coped for a long time using just an 8:2 MM PA mixer. The compromises required are surprisingly few.

A dedicated studio mixer has two distinct jobs during recording:

• It allows signals to be mixed and routed to tape
• It enables a monitor mix of the already recorded tracks to be set up as a guide for overdubbing.

A stereo PA mixer is designed with neither of these functions in mind, but with a little ingenuity and the occasional plugging and unplugging of leads, both requirements can be met.

Figure 1 shows my suggested setup for recording, the only proviso being that you have a mixer with more input channels than you have tape tracks and that the mixer has pre-fade, foldback sends fitted to each channel. If you want to record more than two tape tracks at the same time, then you'll also need a mixer that has either direct channel outputs or channel insert points. In practice, direct outputs are unlikely on this type of mixer, but insert points will do equally well. In the example shown, we have a 16-channel mixer, channels 1-8 being used as inputs to feed signals to tape, and channels 9-16 being used to provide the monitor mix.

Taking channels 1-8 first, these may be routed to either the left or right mixer output using the pan controls, and in this case, the mixer's left and right outputs are patched to the line inputs of the multitrack tape machine. You can use a patchbay to physically move the leads so as to feed the tape tracks you want to record on, or you could 'normalise' the multitrack inputs by feeding the mixer's left output to all odd-numbered inputs and the right output to all the even numbers. This way you can record onto any tape track you wish without repatching, simply by selecting odd or even with the mixer's pan controls and then setting the desired tape track to record. This arrangement does limit you to recording only two tape tracks at a time, but if you're working alone, building up a song in layers, then this may be all you'll ever need.

INSERT SENDS

To record on more tracks at a time, you need to find ways to get more mixer outputs. You can't use the post-fade aux sends because these only work with the channel faders up — which would also feed the signal to the left and right outputs. Similarly, you can't use the pre-fade foldback sends because these will be used to set up your monitor or cue mix, as I'll explain shortly. However, you can use your insert send points, which will provide a duplicate of the channel input signal regardless of the position of the channel fader. In practice, it's best to leave the channel fader down when using this trick so as to minimise the amount of circuit noise and crosstalk sent to the left and right outputs.

Most budget mixers have their insert points wired to stereo jacks which carry both the insert send and return signal. Figure 1b shows how a typical insert point is wired, though you should check with your mixer manual, as I believe some are wired 'tip send' and others 'tip return'. If you're not sure, take a guess, and if you get it wrong, try it the other way around — you won't damage anything. On some mixers, you can simply insert a mono jack plug halfway into the insert jack to get an improvised direct output, but if the wiring doesn't allow this, use either a Y-lead (stereo jack at one end and two monos at the other) or a 'stereo to two monos' adaptor plug and use only the send signal. The return signal should be left disconnected.

Now you have a mixer channel that can accept one input signal and provide one output signal which can be physically plugged into any tape track you choose. Mixer channel 8 in Figure 1 is shown used in this way. The limitations are that you can't mix two or more channels together — you can only feed one mixer channel to one tape track, and the recording level has to be set with the channel input gain control, not the channel fader. In practice, the fact that you can only handle one signal at a time is no problem, as any mixed signals may still be routed via the left and right outputs, as described earlier. In other words, you have the capability to send up to two groups of mixed signal to individual tape tracks, plus as many separate signals as you have spare mixer channels.

In case you were wondering, if you need to connect a compressor to one of the signals that's already being fed out of an insert point, no problem — just patch the compressor between the insert send and the multitrack input. Because you're always monitoring the multitrack output, you can hear the effect of the compressor at all times.

One thing I haven't mentioned yet is that many sound sources can be connected directly to the multitrack inputs without ever going through the mixer. For example, a guitar preamp, mic preamp or DI box could be plugged straight into the tape machine and the record levels set using the level controls on these devices. Similarly, many keyboards can be connected in this way. This is particularly useful if your mixer has no insert points.

MONITORING

Channels 9-16 in Figure 1 are set up for monitoring, sometimes known as the cue mix. Note that all their channel faders must be turned down, otherwise the signal would be routed from the tape machine outputs back to the inputs, causing feedback. The cue balance is actually set using the desk's foldback (pre-fade) sends and the monitor amplifier fed from the foldback output. This is only mono, but that's not a real problem, as you only need a guide mix to enable you to keep time as you add new tracks. The monitor mix level is set using the master foldback control, and because most modern tape machines look after the input/output monitoring status pretty automatically, it is quite satisfactory to monitor the multitrack outputs at all times.

MIXING

This is the easy bit. The mixer left and right outputs are replugged into the inputs of the stereo master recorder which, in turn, feeds the monitoring system; the stereo mix is set up on channels 1-9 in a perfectly conventional way. This leaves channels 1-8 free to accept sequenced MIDI instruments, effect returns, sound effects tapes or whatever else you want to add to the mix.

Hopefully, the theory behind this way of working is fairly clear; the only real chore is the amount of repatching needed. But then, as anyone with recording experience will tell you, repatching is a part of everyday studio life, no matter what equipment you have. Wiring the necessary ins and outs to a small patchbay will help, but if you only need to record one or two channels at a time, and are prepared to link the multitrack inputs as suggested earlier, the amount of repatching you need to do is quite acceptable. There's even a possible sonic advantage to be gained from working in this way: smaller mixers have shorter signal paths, which means that the quality of your recordings might actually end up being slightly better than those made using more sophisticated mixers.