Hands On - Lexicon PCM 70 (part 2)
Ask anyone who makes the best reverb units and theyll tell you Lexicon do. Lexicon have been producing high quality digital reverb units for over a decade and their reputation is second to none, although now there are many devices which could make a reasonable claim to be the best unit available. Once upon a time we had to depend on plate reverb units which were bulky and inflexible, although their basic sound quality was good. Lexicons early model 224 showed us how we could manipulate the quality of the sound by adjusting the reverberation time separately for high and low frequencies, among other features, even though it didnt in all honesty sound all that great. Lexicons more recent top-of-the-range models have certainly gone far beyond what their early attempts achieved sonically, and the fruits of their research filtered down to the more affordable PCM70. The Lexicon PCM70 has certainly been one of the most popular effects units ever and you will find it in many studios across the length and breadth of the country (and around the rest of the world for that matter). If you want to be sure that you are using one of the worlds favourite effects units then patch into the PCM70 and you definitely will not be disappointed.
I have already looked at that other classic effects unit, the Yamaha SPX90, in a previous Hands On instalment. The SPX90 was the first of the multieffects units and could produce just about any effect you were likely to need in the studio. The Lexicon PCM70 doesnt have quite this superabundance of effects (which some more recent units have taken to the degree of overkill), but there is a little more on offer than just reverb. Basically, a digital reverb unit consists of a lot of memory and the processing brainpower to shuffle the temporarily stored audio data about in a way that will sound to our ears like multiple reflections in a room. With appropriate software, the same hardware can be used to create delay, chorus, phase and flange effects, and the PCM70 does pretty well in these departments too. But first, lets look at the way the PCM70 is organised. Once you understand this youll be able to dive into the editing parameters and manipulate the programs to get exactly the sound you want.
Figure 1 shows the front panel of the PCM70. When it first came out we were still getting used to the idea of operating equipment which didnt have too many knobs - either one or none - and all the button pushing you had to do was seen as a necessary unpleasantness (but it was the lack of mechanical hardware that made the equipment affordable). If you were an equipment designer and you were trying to develop an interface to a synthesiser or effects units which used a form of up/down key interface then you would actually find it quite difficult to work out which was the best of the many ways you could implement it. Lexicon chose to use a method which isnt at all intuitive and it is unlikely you could sit down at a PCM70 and get much joy out of it without some serious consideration. With Yamahas SPX processors you use one button to call up the parameter you want to adjust, and another pair of buttons actually to adjust it. With the PCM70 things are a little more complex.