In the last year SOS has reviewed no less than 10 examples of the new breed of so‑called 'Voice Channels', promising a one‑box solution to high‑quality vocal recordings. Derek Johnson & Debbie Poyser present a brief guide to the models we've looked at, to help you decide which you should go for.
The concept of voice/instrument 'channels', offering a set of processes ideally suited to getting a vocal or single instrument performance on to tape, isn't exactly new, but until multitrack tape gave way to computer‑based hard disk multitrack, the demand was never great. However, with a greater emphasis on the quality of recorded sound, the voice channel has enjoyed a huge increase in popularity, both in traditional studios and desktop computer workstations. Analogue studio owners realised that they could make better recordings if they were able to bypass their mixers to keep the signal path short, while workstation owners found voice channels ideal for feeding mic and instrument signals directly into their A/D converters. As tapeless recording has become more affordable, and thus more widespread, voice channels have moved from the fringe of signal processing into the mainstream. There's been a real flood of 'channels' over the past year, ranging in price from under £200 up to almost £2000, and as this spread of prices would suggest, there's now a voice channel for almost every level of the studio market. And, in the words of SOS contributor David Mellor, in the January 1997 issue, if you don't have money to burn there's something to be said for the idea of buying a lower‑cost mic and a voice channel instead of a single expensive mic — this would certainly offer you a wider tonal range than the mic option alone.
We've taken several features as qualifying criteria for inclusion in this article: a voice channel must obviously have a mic preamp, with phantom power to allow the use of mics that require it; it should offer a compressor, as compression is a process most people regard as essential when recording vocals; and it will usually offer at least one other process — typically EQ or psychoacoustic enhancement, de‑essing or gating — and often more than one. Many voice channels also have a line‑level input to allow you to process an instrument.
Joemeek VC3 Pro Channel
(SOS review October 1996)
- Preamp with switchable phantom power.
- Compressor with switchable fast/slow attack, variable Release and Compression controls, Bypass button and single LED for metering gain reduction.
- Enhancer with Drive, Enhance and Q (bandwidth) controls.
- Basic 5‑LED level meter for signal monitoring prior to output level control.
- Line input for instrument or line‑level signal processing.
- Insert point for patching in external processing.
- Mix jack to allow an external line input to be mixed with the unit's main input prior to compression and enhancement.
Joemeek VC3 Pro Channel £199prosEasy to set up.Powerful, up‑front compressor sound.Effective enhancer.Very sensible cost.consVery basic metering.Unbalanced outputs only.summaryThe most cost‑effective voice channel on the market. If you like the sound of classic rock recordings, the chances are that you'll love the Pro Channel.
£199 including VAT.
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LA Audio MPX1 Mic Processor
(SOS review August 1997)
- Preamp with phantom power, phase reverse button, switchable high‑pass filter, single peak LED for input metering. Additional DI input with 500kΩ input impedance on rear panel, for use with electric guitars or basses.
- Expander/gate. Expander has fixed ratio and variable threshold, with fixed attack and release times, and a green LED to indicate gain reduction.
- Compressor with side‑chain insert point, basic de‑essing filter and fully variable threshold and ratio controls. Since the compression is largely programme‑dependent, there are no attack and release controls, but options for fast and slow attack and release characteristics are available. Gain reduction is shown by a six‑section LED meter in the Master section, and there's also a make‑up gain control and a bypass switch.
- 4‑band equaliser with shelving high and low sections and two fully parametric mid sections, Q controls with fully variable bandwidth from three octaves to one semitone, bypass button and low‑pass filter.
- All sections have their own inputs and outputs (unbalanced jacks) on the rear panel, so that they can be used alone or chained in any order. Main output available on both balanced XLR and unbalanced jack.
- Link jack so that two units can be used for stereo signals.
LA Audio MPX1 £299prosCreditable range of features for the price.The various sections sound good, and there's a full four bands of EQ.Separate input/output access to all sections.consQ pots are small and fiddly.Expander can be rather abrupt on some material.summaryA well‑designed, attractively priced unit that delivers sonic quality where it counts, at the expense of a couple of minor ergonomic flaws.
£299 including VAT.
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DBX Project 1 Model 286A
(SOS review of original 286 January 1997)
- Preamp with high‑pass filter and 48V phantom power.
- Compressor.
- De‑esser.
- Enhancer with patented LF Detail control (applies boost at 80Hz and cut at 250Hz); and HF Detail control (to apply 'intelligent' enhancement dependent on programme material).
- Expander/gate.
- Line input for instrument processing.
- Insert point for patching in external processing.
Reduced detail is given on this product because it is an upgrade on the previous 286 and has not yet been reviewed by SOS. It's worth taking a look at the 286 review, but bear in mind that the 286a has not only had its facilities improved (phantom power is now at the standard 48V, not 15V), but has also had a fairly substantial price cut, from £350 for the 286, to £230 for the 286a.
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Joemeek VC6 Meekbox
(SOS review November 1997)
- Preamp with switchable phantom power
- Compressor with Compression (threshold), Ratio, Attack and Release controls, and green status LED to show when gain reduction is taking place.
- Enhancer with controls for Drive, Q and Enhance with amber LED which flickers when enhancer is working.
- Unbalanced jack inputs for line‑level and instrument‑level signals.
- Insert jack for patching in extra processing.
- Mix In jack to allow external line signals to be mixed into the signal path before compressor stage.
- Output level control and 5‑stage LED output‑level meter.
Joemeek VC6 £349prosFully variable controls.Helps vocals sit nicely in a mix.Very musical compressor and effective enhancer.consNo compression gain reduction meter, just a single LED.summaryThough corners have been cut to keep the price down, they don't detract from the sound or flexibility of this unit.
£349 including VAT.
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TL Audio VP2051 Valve Voice Processor
(SOS review November 1996)
- Preamp with switchable phantom power, phase reverse and low‑pass filter.
- 4‑band EQ with high and low shelving filters (switchable shelving frequencies), bypass button and pre/post switch to place the EQ before or after the compressor in the signal chain.
- Compressor with soft‑knee characteristic, insert point, switchable fast/slow attack and release times, Threshold, Ratio and Gain Makeup controls. The compressor sections of two VP2051s can be linked for stereo operation, and the unit features an 8‑section bargraph meter that can be switched to show gain reduction or output level.
- Line input on balanced jack, and two further unbalanced line inputs (one front‑panel, one rear‑panel).
TL Audio VP2051 £469prosConvincing vintage tube sound.Well engineered and stylishly presented.All the modules in the Voice Processor stand up well as processors in their own right.Recent price reduction makes it very good value.consNone.summaryTL Audio have created the right balance of sound, features and price. The VP2051 is a wonderful all‑rounder that can be used to sweeten just about any mono signal, not just a microphone.
£468.82 including VAT. (Soon to be joined by a similar model in the new Ivory range; see last month's news pages for details.)
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Joemeek VC1 Studio Channel
(SOS review April 1997)
- Preamp with phantom power and high‑pass filter.
- Compressor based around unique Joemeek‑design photocell and LED gain element, with soft‑knee characteristic. Full Ratio, Threshold, Attack and Release controls are provided, as are a large VU meter which can show either gain reduction or output level, and a gain reduction LED to show compressor action.
- Enhancer based on dynamic equaliser principle, with Drive control (affecting both degree and 'tone' of enhancement) and accompanying bi‑coloured LED to indicate when Drive amount is about right; Enhance control (to set the amount of enhanced signal mixed back into main signal path); and Q control to set the sharpness of the filter (affecting the duration of high‑frequency harmonics).
- Balanced line input and unbalanced jack input for instrument processing.
- Insert jack after mic preamp for patching in external processing such as EQ.
- Output gain control to compensate for gain loss caused by compression.
- Three different output formats: quarter‑inch balanced jack line output; transformer‑balanced low‑impedance XLR; unbalanced jack.
Joemeek VC1 £704prosWarm, musical sound.Very effective compressor and enhancer.consNo auto‑compression mode.summaryA great‑sounding 'character' unit with a flexible range of input and output options.
£704 including VAT.
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LA Audio Classic Channel
(SOS review November 1996)
- Preamp with switchable phantom power and phase reverse.
- 4‑band EQ with high and low sections and two sweep mid sections, with high‑pass and low‑pass filters, and bypass switches for both 4‑band and filter sections.
- Compressor, designed around FET gain element for tube‑like character, with soft‑ and hard‑knee characteristics; Threshold, Attack, Release and Ratio controls (the latter variable in six steps from 1.5:1 to 20:1, rather than fully variable); output gain control; bypass button with status LED; side‑chain access; VU meters to show gain reduction and output level.
- Switchable, fixed‑frequency de‑essing filter.
- Line jack input for instrument or line‑level processing.
- Insert point for patching in external processing.
- Two units can be linked for stereo operation.
LA Audio Classic Channel £817prosTransformers and FETs contribute to a warm, vintage sound, but with the low‑noise performance of a modern design.Easy to operate.Smart styling.consDe‑esser can turn violent in inexperienced hands.summaryA convenient and well‑designed processor that combines a pleasing tonal warmth with effective compression and EQ. Ideal for high‑quality vocal or instrumental recording.
£816.63 including VAT.
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Focusrite Green Voice Box
(SOS review November 1996)
- Mic preamp with switchable phantom power, phase reverse, mute button and high‑pass filter, status LEDs and 5‑section LED level meter.
- Compressor, with hard‑knee characteristic, and Threshold, Ratio and Make‑up Gain controls. Attack and release times are pre‑optimised for vocal use, but an auto‑release function is available for unusual material. There's a bypass button, and a switch that causes the LED level meter to show gain reduction.
- De‑esser with Threshold and Bandwidth controls.
- Expander with 2:1 ratio.
- 3‑band equaliser with low and high shelving sections and sweepable mid‑range. Bandwidth can be set to normal or Notch, the latter for attenuating spot frequencies.
- Two units can be linked for stereo operation.
Focusrite Green Voice Box £998prosSupremely transparent sound.Predictable, intuitive operation.consNo line input.summaryThough not cheap, the Voice Box allows project studio owners to buy into Focusrite quality for considerably less than the cost of the Red range.
£997.58 including VAT.
Focusrite Green Channel Strip
(SOS review July 1997)
- Preamp with phantom power, phase reverse and 10‑section LED signal level meter, which can also be switched to indicate compressor gain reduction and expander/gate operation.
- High‑spec 4‑band sweep EQ with switchable mid‑range Q and high‑ and low‑pass filters.
- Expander/gate with Threshold and Release controls, gate Bypass button, Fast switch for use with percussive sounds, and external key input.
- Compressor with Threshold, Ratio, Release and Make‑up Gain controls. Attack time controlled by 'Fast' button and release time switchable to Auto mode. Overload LED to show clipping at output. De‑essing can be achieved in conjunction with the Channel Strip's filters.
- Line jack and XLR line inputs for instrument processing.
- Link jack, to allow two units to track for stereo applications.
Focusrite Channel Strip £1118prosClassic Focusrite performance and transparency.Easy to set up.Versatile — can double as the ultimate DI box.consLegending small and sometimes obscured by the controls unless you're looking straight on.summaryThough the Green range is a budget range for Focusrite, the Channel Strip isn't cheap — but the quality of processing is beyond reproach, and the unit has many applications, in both recording and mixing.
£1173.82 including VAT.
Joemeek VC2 Tube Channel
(SOS review September 1997)
- Valve preamp, with mic and line inputs, phantom power, phase reverse, LF rolloff switch (the latter three with status LEDs).
- Compressor with Threshold, Attack and Release controls, and switch for selecting one of two preset ratios. Gain reduction may be shown on the large VU meter, and there's a bypass button.
- Enhancer with Drive, Q and Enhance knobs, dual‑colour Drive LED to help set up drive level, and bypass button.
- Insert jack, for patching in external processing.
- Mix In jack to allow external line signals to be mixed with the VC2's mic/line signal before compression.
- Link socket for stereo‑linking two units.
Joemeek VC2 £1760prosEasy to set, with clear metering.Helps sounds sit properly in a mix.Clean mic preamp section and very musical compressor.consSome users may worry about the lack of a separate compressor ratio control.summaryA distinctive sounding signal processor that makes light work of vocals and is flexible enough to be used on instruments.
£1760 including VAT.
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Guide compiled by Derek Johnson & Debbie Poyser from SOS reviews by Paul White and David Mellor.
Why Pay More?
As you can see, the prices of voice channels can differ enormously, so what do you get at the high end of the market that you don't get in a £200 unit? Arguably the most important section of a voice channel is the mic preamp, and there's little sense in buying an external model that doesn't exceed the performance of your console mic amps. Certainly the direct signal path is an improvement over a conventionally used mixer, but the same minimum path benefits can be achieved by taking the direct out or insert send from a regular mixer channel. What you're really paying for with a high‑end voice channel is a very low noise figure at all gain settings, a wide frequency response for good transient handling, plenty of headroom and exceptionally low distortion. Tested with a good mic, the difference is often quite dramatic.
As tapeless recording has become more affordable, voice channels have moved from the fringes of signal processing to the mainstream.
The compressor section is also important, but here character is often as important as accuracy. For example, the Joemeek designs use an opto compressor to give a particular vintage sound, whereas the Focusrite's compressor evens out the vocals with virtually no sign of processing, unless you are deliberately heavy handed. If the channel includes equalisation, this too needs to be better than a typical mid‑price studio desk EQ, and the real test is to see how much EQ cut or boost you can apply before the sound becomes unnaturally nasal, harsh or honky. Top‑end units let you change the sound dramatically with few negative side‑effects, whereas cheap equalisers have to be used very sparingly to avoid ruining the sound.
Finally, check what features are left out on the cheaper models and whether they matter to you. Sometimes you'll find that the cheaper models provide the same basic quality as the more expensive units in the range, but the metering may be simplified and the controls may have been pared down to a minimum. For me, this is a far better way to go than keeping all the bells and whistles but compromising on circuit quality. Whatever model you choose, remember that your mic signal will never sound better than it does at the output of your voice channel — no matter how good the rest of your system, all it can do is add further noise and distortion. With any luck, it won't add much, but you can be certain that the better your front end, the better the ultimate quality of your recording.
As tapeless recording has become more affordable, voice channels have moved from the fringes of signal processing to the mainstream.