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Lexicon PCM 80

Article from The Mix, February 1995

Studio reverb, sucessor to the PCM 70


The Lexicon PCM 70 has long been a favourite among engineers and producers everywhere, but can such a classic reverberator be improved upon? There are no doubts in Bob Dorman's mind, as he swathes his latest tutorial in the glorious sound of the PCM 80...


In days of old, you had only to mention the name Lexicon and your average sound engineer would break out into a large grin and begin salivating.

In the 80s, Lexicon produced a state-of-the-art digital reverb in the form of the 224XL, which sounded like a million dollars and cost nearly as much. Along with AMS digital effects units, a Lexicon reverb soon became the sound that producers would insist upon. Trevor Horn for one, frequently bathed his productions in Lexicon effects. Perhaps it's no surprise that the name appeared on ABC's Lexicon of Love album, and maybe this lavish production would have been more accurately entitled The Love of Lexicon.

Cheaper 1U rack versions started to emerge, and Lexicon made theirs in the form of the PCM 60. For many, this was their first encounter with a Lexicon reverb. The PCM 60 may not have produced the same frantic response from our drooling engineer, but for the price, you could capture a glimpse of the classy textures offered by the 224. The PCM 60 only has presets available, offering room or plate emulations with short, medium or long decays, and a selection of room sizes, plus High and low EQ contours. Simple but effective, and certainly worth plugging in if you happen to come across one.

When the PCM 70 came onto the scene, things started to sound very different. The PCM 70, with its comprehensive MIDI specification and fully editable parameters, once again became a studio favourite, not only for its sound but for the fact that it didn't require a second mortgage. Now, around eight years on and numerous software revisions later, Lexicon hope to woo the faithful once again with the PCM 80. They've already succeeded in catering for the consumer home recording market with the LXP series and their newer Alex, Vortex and Reflex units. So now it's time to address the needs of the professionals, with more editing functions than you can shake a stick at.

Overview



The PCM 80 follows the looks of its predecessor, but up close it's actually very different. For a start, you get a much better-looking LED display, and the front panel now has two rotary knobs for Adjust and Select functions. Using the Up/Down keys you can skip through the four banks, each containing 50 Program (preset) sounds per bank. Register (user memory) banks offer 200 locations to store your personalised effects, and if that's not enough for you, a further 2,350 effects can be stored on a 1 Mb PCMCIA Type 1 SRAM card. Another interesting feature is the ability to expand the memory within the Lexicon using SIMMs. Inserting these memory modules expands the factory delay time of 2.6 seconds up to 42 seconds!

The PCM 80 is a lot easier to navigate than its predecessor, the PCM 70. The latter had only one knob, and you'd have to use one of ten keys to select the effect in that bank. With the PCM 80, life is much easier, as you can scroll through the available programs using the Select knob instead. Pressing the Load button will then input your chosen effect into the memory. The PCM 70 and 80 are idiosyncratic when it comes to loading up effects, as they take about a second to complete the task. So if you want to do any rapid program changes during a mix, you'll have to be sneaky about where you choose to do it. However, when it comes to changing parameters within a program, the response of the PCM 80 is glitch-free. Lexicon actually make these adjustments easier with the Adjust knob, which is initially dedicated to altering the relevant characteristics of a given effect. So if you're using a reverb, then a quick twist of the adjust knob allows instant editing of the decay time. You can decide what parameters will be available on the Adjust knob if you want, but for the most part, the Lexicon choices are intelligent ones.

Plugging in, analogue inputs and outputs are accessible through balanced (TRS) 1/4" jacks. The PCM 80 detects how many jacks are inserted to the inputs and outputs, and makes appropriate changes. For example, if you use just one jack to feed the input, then the signal will be evenly routed to the left and right effects channels. The metering consists of a parallel stack of LEDs that show the differences in left and right input from analogue and digital sources. At 0dB, a red overload LED warns of potential dangers at any stage in the effects processing, as some algorithms can build up in level over time. Besides the main input level knob on the front panel, analogue and digital input levels are also accessible from within Control section. The Control key hides numerous goodies, and among them is a facility that enables you to mix sounds from analogue and digital sources.

Digital interfacing



You can't use the digital input to the PCM 80, without first selecting the clock source to external (which is yet another feature of the Control section). The digital timing information is then supplied by the digital source you're connecting to PCM 80. When the clock source is set to internal, the PCM 80 mutes the digital input and only accepts an analogue input. The digital output works in both cases, and the unit can be set to work at 44.1kHz and 48kHz. SCMS is also available, and defaults to a neutral multiple copy status. Nevertheless, it is intriguing that you should find it there at all, as I doubt that there will be so many final mixes that'll find the PCM 80 as their last port of call.

I used the digital interfacing capability of the Lexicon extensively throughout the Effects Tutorial that appears on this month's CD. Some sounds came from DCC recordings, and were sent into the Lexicon's digital input and then sent from the digital output to a hard disk recording system, where the effected sounds were compiled with the voiceover. It help keeps things clean... and tidy, as only two leads were needed!

Algorithms and Editing



The four effects banks within the PCM 80 each contain a different group of effects. Residing in Bank 0 are the Multi Effects, Modulation Effects and Special Effects. Bank 1 stores the Rhythmic and Echo effects, together with Ambience treatments, while Bank 2 contains the EQ, Spatial Gain and Resonant chord effects. Finally, in Bank 3 you reach the good old fashioned Reverb effects plus Processed Reverb and Remix effects. A comprehensive range that is derived from only ten stereo algorithms and all of them include an "...uncompromised stereo reverb effect".

In general, there are two classes of algorithm: 4-Voice and 6-Voice. PCM 70 users will be familiar with this type of arrangement. The voices are like additional layers that you can pan and mix within the program. For example, you can add multiple delays of completely different timings, controllable independently or (using the Master control function), all at once. With most parameters - in particular time delay or feedback effects - there is a Master control. This will vary the active voices by a percentage of their actual setting, thus preserving the relationship between the individual voices.

With some effects there are around 100 tweakable parameters, which the wholesome manual endeavours to explain. If you haven't got it to hand, then press and hold down the appropriate key and a message will spring forth with a brief explanation of that function. Very neat. Naturally, it's not in the scope of this review to discuss all parameters in detail, yet the twelve buttons and two data knobs are just enough to navigate through them all without losing your mind. But if that's all too much, then you don't have to have a science degree to work the PCM 80, as there are two operating modes: Go and Pro.

Go is for those who require instant gratification, as it limits the amount of parameters at hand to a maximum of ten. While this is definitely a splendid idea, I do feel that such simplicity is not what you paid over two grand for. If you want to get serious, then you'll have to make a brief foray into the Control menu, and set the system to Pro. Depending on how keen you are, this is where the fun starts (or the headaches begin). Inside the bowels of the Edit menu is the internal modulation patching system. This allows you to apply LFOs, envelopes, time switches and latches to virtually any effect parameter. Such systems exist on synths such as the Ultra Proteus, and can provide staggering real time effects. But if you just want to get an everyday delay up and running, then you can use the Tap key to inform the PCM 80 of the tempo. Alternatively, you can MIDI it up and use MIDI clock information from a sequencer or drum machine, to allow the Lexicon to track any tempo changes.

MIDI in brief



Like even the most basic Lexicon effects units of recent times, the PCM 80 is no slouch when it comes to MIDI implementation. On the simplest level, there is a program change assignment table allowing 128 patches to be configured. Any effect can be called up with the aid of program bank change messages. This could prove very useful if you're using a memory card, as having to hunt through 2,350 programs would soon get studio clients clock-watching. MIDI data dumps are of course possible, and are a long shot from the tape dumps of the 224XL. Numerous control changes and Sysex messages are also digested with gusto by this powerful signal processor.

Sound opinion



Program bank 3 reveals a few familiar faces. Snare Chamber for one, described as a 'classic from the PCM 70', will delight those that don't leave a mix without it. For most of these room and plate emulations, turning the adjust knob is all that's required: typically altering the decay to suit. There's bound to be a new 'classic' among them, like Piano Hall with its gentle modulation, which mildly detunes the fading reverb. Jet Chamber was my favourite, and can be heard on the final snare hit in the intro of the CD tutorial. Its stereo flanging of the reverb effect is reminiscent of Yamaha's Rev 5, only cleaner. The vast majority of programs are classy sounding reverbs and echo effects, which didn't exactly blow me away in their native form, but could no doubt be knocked into shape, to create anything from a cavern or a cupboard. The esoteric effects too, while impressive and teasing to the ears, have a limited application, and you might want to dedicate this device to a good all-round reverb, rather than a one-off effect.

Verdict



The PCM 80 is indeed a worthy successor to the PCM 70. The digital interfacing, stereo inputs, improved display and editing facilities are welcome features. The Go edit option means that operating it need not be a black art, while Pro edit is for none but the brave. On the other hand, he or she who dares, wins. My only complaints would be that you can't seem to get a shorter delay time than 1mS. Shorter times exist on far cheaper devices, and can produce some really airy phasing effects. Also some reverbs were far too reflective, and produced annoying early reflections, particularly on drums. Finding a way to edit this out escaped me, and nor was altering the pre-delay the answer.

It's difficult to give a professional Lexicon reverb a bad review. You know that inside the box there's bound to be a sound that works for you. The simplified editing may well tempt the fainthearted to invest in one, but if all you're going to do is call up the presets, then you have to ask yourself if this really the device for you. The PCM 80 is a serious effects tool, and as a result costs serious money.

The essentials...

Price inc VAT: £2,113
More from: Stirling Audio, (Contact Details)


Spec check

Audio Input
Connectors 1/4 inch jacks (x2)

Impedance
0dB/balanced switch position: 100kΩ balanced
20dB/unbalanced switch position: 50kΩ unbalanced

Audio Output
Connectors 1/4 inch T/R/S jacks (x2)
Impedance 125kQ, each side, balanced
Levels +18dBm max, full scale (+4 dBu setting) balanced, unbalanced +4dBm max, full scale (-10dBu)

Protection

Relays provided for output muting during power on/off

A/A Performance (Analog In/Analog Out)
Frequency Response 10Hz to 20kHz, +/- 0.5dB
Cross-talk -55dB max, 10Hz to 20kHz
S/N Ratio 90dB min, 20kHz bandwidth
THD 0.008% max, 10Hz to 20kHz
Dynamic Range 90dB min, 20kHz bandwidth

Digital Audio Interface
Connectors Coaxial, RCA type, in/out
Format Conforms to S/PDIF CP-340 Type II and IEC 958 consumer standards and also accepts AES data format

Internal Audio Data Paths
Conversion 18 bits
DSP 18 to 24 bits

Audio Memory Configuration
Base Memory Two 256k x 18 DRAMs
User Expansion Two SIMM sockets provided for either 1 Mb x 9, 4 Mb x 9 or 16 Mbytes x 9, 70 nSec DRAM modules
External Memory PCMCIA Type 1 card (up to 1Mb SRAM).

Control Interface
MIDI In, Out and Thru
Footswitch 1/4 inch T/R/S jack provided for 2 independent momentary footswitches. System detects normal-open or normal-closed on power up
Foot Controller 1/4 inch T/R/S jack provided for footpedal (10kΩ minimum, 100kΩ maximum)

General
Dimensions 19" W x 1.75" H x 12" D, 19 inch rack mount standard, 1u high
Weight 6.4lbs (2.9kg)
Power 100-240 VAC, 50-60Hz, 35W, 3-pin IEC power connector


On the RE:MIX CD

Bob's effects tutorial on the Re:Mix CD makes extensive use of the PCM80's luxurious algorithms.



Previous Article in this issue

Club class

Next article in this issue

Acoustic algebra


Publisher: The Mix - Music Maker Publications (UK), Future Publishing.

The current copyright owner/s of this content may differ from the originally published copyright notice.
More details on copyright ownership...

 

The Mix - Feb 1995

Donated by: Colin Potter

Coverdisc: Mike Gorman

Control Room

Gear in this article:

Studio/Rack FX > Lexicon > PCM80


Gear Tags:

Digital FX
Reverb
Delay

Re:Mix #8 Tracklisting:

08 Bob Dorman's patches


This disk has been archived in full and disk images and further downloads are available at Archive.org - Re:Mix #8.

Review by Bob Dormon

Previous article in this issue:

> Club class

Next article in this issue:

> Acoustic algebra


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