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Magnificent Seven

Studiomaster P7 Multitrack Mixing Console

Studiomaster have at last entered the in-line console fray with this well-specified and attractively-priced desk. RM checks it out.

Studiomaster have finally produced an in-line mixer — but can it compete with the profusion of models already on the market? Mike Simmons finds out.

The Studiomaster P7 is an in-line 16:8:2 mixing console expandable in blocks of eight channels up to a maximum of 40, and with MIDI muting. It's aimed squarely at the low- to mid-priced market currently occupied by machines such as the Soundcraft Spirit or Allen & Heath GS3, and is the first in-line mixer that Studiomaster have produced. In cosmetic terms, the P7 isn't too dissimilar to the consoles just mentioned. It utilises a non-modular approach to construction, in that the entire front panel is fabricated from a single sheet of steel; plastic moulded end-cheeks add a touch of styling to what is otherwise a very workmanlike design, and additional expander modules may be attached to the right-hand side of the console.

The desk is a pleasing mid-grey colour with pale grey screening, which I found just a little too busy, around the controls. I actually thought that the screening was highly attractive, but in use, the legend can be difficult to read. As supplied, the P7 is configured to run with semi-pro equipment working at the -10dBv operating level, but the levels may be changed to +4dBu by means of simple internal modifications.

To those not yet familiar with the concept, in-line mixers are often perceived as somewhat complicated when compared with the more traditional split console, but there are certain advantages which have made the in-line approach increasingly popular over the last few years.

Ring For A Brochure!

If you'd like a P7 brochure, or any further info on the Studiomaster mixer range, Studiomaster's Stake (real name!) can help. Just call on (Contact Details), or write to the address at the end of the review.

The greatest drawback to the split console is the limited number of monitor channels — typically there might be eight or 16. With an in-line system, the user has access to as many monitor channels as the mixer has input channels, since each channel strip has its own monitor input. The increased popularity of this system may well reflect the introduction of sequencers and budget 16 and 24-track recorders. Not only do the monitors serve as a means of setting up a control room mix while recording, they also double as additional line inputs when you come to mix. If there are sequenced instruments running from a sync code on tape, the more line inputs available the better.

There is a trade-off here, however, since the monitor section of an in-line mixer will tend to be more limited in the facilities it offers than that of a split design. Specifically, there may be a more limited EQ and fewer Aux returns. Most manufacturers endeavour to reach some kind of compromise here and, as we shall see, Studiomaster have done their best to meet all eventualities.

The P7, typically for an-line mixer, tends towards squareness, being less broad and somewhat deeper than its split counterparts. The input sockets are located towards the back of the top panel, raking slightly away from the user but still completely accessible. I find this a far more satisfactory arrangement than having a mass of cables terminating at a panel on the rear of a device, since it makes any repatching that needs to be done far more straightforward.

Channel Strip

Each channel is served by a Line input and Tape In and Out sockets on quarter-inch jacks, an insert point on a stereo quarter-inch jack, and a balanced XLR Mic socket. The P7 provides the latter with 48V phantom power which is switchable on each channel. These switches, which are located between the socket panel and the main input channels, are sufficiently recessed to make it highly unlikely that they would ever be switched on by mistake. The power supply, a separate 2U rackmounting device, also boasts a global phantom power switch, so those not using phantom power at all can reduce the risk of any accident to zero, simply by isolating the power at source. It's good to see that the power supply needs no fan, with the result that a potential source of background noise has been removed.

Each channel strip is topped by an Input Swap switch. This is a fairly conventional device which ai lows the user to make the most of the facilities available, whilst reducing the amount of repatching needed to a minimum. While recording to the multitrack, the line inputs are normally routed through the input channels and onto the tape tracks via the Group faders. At the same time the outputs from the tape machine run to the monitor inputs on the desk, and so allow the engineer to set up a rough monitor mix for the control room. At mixdown, pressing the Swap button routes the tape recorder outputs into the input channels, and connects the line input sockets to the monitor channels. Given the number of mixer channels required by even the most basic MIDI studio, the attraction of the in-line system becomes obvious — the P7 would allow the user to mix down a total of 16 tape tracks and 16 sequenced instrument outputs — and that's before any of the Aux returns are pressed into use!

Following the input Swap button is a 20dB mic pad button which allows the user to attenuate any particularly extreme mic signals that might otherwise overload the input stage — a close-miked kick drum, for example. This is accompanied by a mic/line input select switch and the obligatory rotary gain control.

Though the P7 boasts only eight Groups, it is in fact possible to record to up to 16 tape tracks simultaneously. This is made possible by a Group/Direct switch which, when depressed, routes the channel signal to its own channel output rather than to the Group fader. There are no dedicated Group output sockets since the individual channel outputs are used to fulfil this function. Thus the Tape Out socket on channel 1 is actually the output for Group 1, that on channel 2 the output for Group 2, and so on. This pattern is repeated from channels 9-16. Any voice or instrument which needs a tape track of its own can be isolated from the grouping system by means of the Group/Direct switch, which effectively turns that input channel into a separate 1:1:1 mixer. The easiest way to use this system would probably be to use the first eight outputs as Group outputs and those remaining for any channels going to individual tape tracks.

At first sight, the EQ on the P7 looks like a conventional 4-band system with sweep mids. There are Hi and Lo controls offering 16dB of cut and boost at 12.5kHz and 60Hz with a shelving response, plus a pair of sweep Mids which provide a 'bell' response and again offer 16dB of cut and boost. The lower of these operates between 100Hz and 2kHz, while the higher sweeps between 500Hz and 10kHz, which is a wider sweep range than you'd expect to find on a split console. This is all well and good, but it's important to remember that there is no dedicated EQ on the monitor section whatsoever. Studiomaster get around this by allowing the user to switch the Hi and Lo controls (as a pair) into the monitor signal path. Because of the extended range of the sweep mids, they function as a full-range equaliser for the input channel. There is, undeniably, an element of compromise about this arrangement, but it would be impossible to build a mixer to the price Studiomaster are asking for the P7 without introducing a number of compromises, and many professional consoles costing much more than this one use exactly the same trick. The EQ section also features an EQ cut button, which is a very welcome addition. Besides allowing the user to check whether or not the EQ applied to a particular signal has, in fact, improved matters, it also provides a means of maintaining a minimum signal path in those situations where no EQ is needed.

P7 Master Section
(Click image for higher resolution version)

Each channel strip is provided with six auxiliary controls. Three of these are dedicated to the Input channel, while one is dedicated to the monitor section. The remaining two are switchable as a pair between the input and monitor signal paths, allowing them to be deployed wherever they are most useful. All of them are post fade except for Aux 5 and 6. An interesting feature here is that Aux outputs 5 and 6 are automatically mixed together if no plug is inserted in the Aux 6 output socket. This provides a useful degree of flexibility when setting up cue mixes sourced from both the input and monitor channels.

Contrary to expectations, the six auxiliary controls are not arranged in strict numerical order on the channel strip. This is because the monitor section — little more than a simple gain control and pan pot — is located directly between Aux 4 and the dedicated monitor auxiliary, Aux 5. This makes perfect sense when it comes to using the machine, but does take a moment or two to get used to. Also located between Aux 5 and 6 are the AFL and Mute/SIP buttons dedicated to the monitor section. These buttons, in common with all the others serving a similar function on the machine, are accompanied by small LEDs, making it immediately apparent when a particular function has been implemented. The Mute button, like all the mutes on this desk except those dedicated to the Aux sends, is a dual-function button operating either as a mute or 'Solo In Place'. The mute buttons are all connected to the MIDI muting system which I will be looking at a little later, but their use is pretty self explanatory; pressing the button mutes the channel, as well as any auxiliaries assigned to that channel.

Following the monitor section and auxiliaries we come to the Pan pot, a row of routing buttons and the master fader. The Pan pot serves the established dual function of either positioning the signal within the stereo mix or, in conjunction with the Group buttons, steering it to the Group buses. The faders are long-throw carbon types and have a reasonable feel with very little physical resistance. At the top of the fader are the Mute/SIP and PFL buttons. Because the signal is Pre fade, it's possible that pressing this button can have unpleasantly loud consequences, as the signal level corresponds to that of a fully open fader. Fortunately, a control on the master section of the desk allows the user to attenuate the signal.

Master Section

The master contains the eight Group faders, the Master Left/Right faders and all the Aux send and return controls. In addition there is a talkback/oscillator section, two-track routing and monitoring and the main monitor and phones level controls. The MIDI muting section is located directly above the Group faders and comprises a two-digit LED numeric display and 11 buttons. This communicates with the outside world via a standard set of MIDI In Out and Thru sockets on the rear connector panel.

The Group faders are arranged as four pairs, each with its own PFL button and a Group to L/R button for each pair. This latter enables the Groups to be routed into the stereo mix for the creation of subgroups while mixing. Insert points are provided for all the Group outputs and for the master Left/Right output. All Aux sends have master level controls, Aux 1 to 4 also having Mute buttons. Aux sends 5 and 6 have AFL buttons.

As a concession to the prominence of stereo effects units, all four returns are stereo and have two-band EQ, level and Pan controls as well as an Aux 6 control. There is no Mute on the returns but there is full routing, allowing them to be directed to any of the Groups or to the Left Right mix buss.

There are separate 16-section LED meters for the Group and Left/Right outputs, the Right meter doubling as the PFL meter whenever one or more PFL/AFL buttons are pressed. As its name might suggest, the PFL, or Pre Fade Listen, signal is quite independent of any fader setting and the signal level displayed on the far right meter can be used to set the channel input Gain control. Since pressing PFL or AFL only solos the signal to the control room monitors and meter — and not to the master outputs — it's possible to use it during a mix without interrupting the main stereo output feeding the master tape machine.

The talkback is handled by an internal electret mic and may be routed to the Group outputs or to Aux 6 for cue purposes. The test oscillator is switchable between 1 and 10kHz and may be routed only to the Group outputs. A nice touch is the recessed oscillator button, which makes accidental operation unlikely.

Unusually for a desk in this price range, facilities are provided for the connection of two stereo tape machines, with further buttons allowing the signal from one to be routed to the input of the other. By this means it is possible, for example, to leave a DAT machine and cassette deck permanently connected to the desk and copy from one to the other without any repatching. The connectors for one of these machines are on quarter-inch jacks, while those for the other are on phono sockets. The two sets of sockets are simply labelled A and B, and it's possible to select either as the signal source at the press of a button. The return from either machine can be routed to the monitors, again at the press of a button. The end of any mix is often marked by requests for copies of the master tape, and this configuration certainly makes things as easy as they can be for the harassed engineer.

One minor criticism I have to make about this machine centres around the ambiguity with which some of the sockets are labelled, and the way in which they are arranged on the panel. It isn't a real problem, but it is something that could have been improved either by better layout or by clearer labelling.

P7 Channel Strip
(Click image for higher resolution version)

A particularly pleasing feature is the provision of two pairs of monitor outputs, thus allowing the user to switch between main and nearfield monitoring systems. The headphone outlet duplicates the control room monitor output and has a separate level control. Another rather interesting feature is the inclusion of an effective security feature. On powering up, the machine remains unusable until a four-digit security code is entered. The operator is allowed three attempts at remembering what the code number is — if the right number isn't input within three tries, the machine will lock up for two hours with all the channels muted. Removing the mixer's internal battery still leaves the machine immobilised, since the code is retained in a smart chip. This facility can be disabled by the user entering a PIN number of 1111, but anything that's likely to deter theft has got to be good news.

"One rather interesting feature is the inclusion of an effective security feature. On powering up, the machine remains unusable until a four-digit security code is entered."

In Use

The P7 works well and presented me with no nasty surprises. If I had to find a criticism, it would be in the cosmetic department; the legending is rather small and a touch too busy, while the general styling and grey paintwork does little to set the P7 apart from its competitors. I found it a little disconcerting to discover that the monitor control was in no way distinctive — it's arguably the most important knob on the console, and I feel it should stand out in some way.

As in-line mixers go, the operation of this model is quite conventional though not all mixers use the 'Group Direct' system employed here, which I feel is a very useful addition. Anyone familiar with other Studiomaster desks will know what to expect from the EQ, which offers a good combination of musicality and versatility. You do lose out a little when you split the EQ, but if you only have to do this for MIDI sound sources, then the chances are you'll still have more than enough control available.

The audio signal path is about as quiet as you'd expect for a well-designed mid-price mixer — actually very good. There's no noise problem with the mic amps unless you're asking them to do an unreasonable job, such as amplifying bird song at 200 yards using a dynamic mic, and the individual phantom powering is very welcome. If you crank the monitor gain right up, you might hear a little crosstalk in some situations, but this is no worse than on any other similar desk and certainly gives no cause for concern.

The MIDI muting is very effective, with negligible breakthrough when channels are muted, and because the switching occurs over a period of several milliseconds, there are no clicks, even when several channels are muted or unmuted at the same time. On a practical level, the MIDI muting system is very easy to use, and though the system of using controller information does use more sequencer memory than simple note information on its own, the software does allow this data to be reduced at the expense of a longer 'catch up' time when a tape is started part way through. And for those who can live without it altogether, it can be disabled, leaving the mutes running on note data only. The fact that mutes are included on each of the Aux sends permits greater levels of creativity than would otherwise be possible and because all four returns are stereo, you're unlikely to have to use up valuable channels to handle effects. These could also be pressed into service as additional line inputs if need be.

"Given its modest price, this is a very attractive mixing console offering all the features expected of a serious multitrack desk."


Given its modest price, this is a very attractive mixing console, offering all the features expected of a serious multitrack desk. Because of the in-line format and the Group Direct buttons, recording is not limited to 8-track but could easily be extended to 16 or 24-track without undue compromise — though you'd ideally need to add at least one expander module for 24-track use. In fact, the modular aspect of the P7 gives it the edge over some of its competitors and it is possible to add up 24 further channels without requiring a larger power supply. Anyone capable of using a screwdriver can fit the expander modules and the completed assembly is still surprisingly rigid. All connections are made by means of plug-in connectors so there's no soldering necessary.

Studiomaster P7

  • Versatile muting system.
  • Musical sounding EQ.
  • Good overall sound quality.
  • Expandability.
  • No PSU noise.
  • Good range of facilities.
  • Can operate at either -10dBv or +4dBu.

  • Graphics a little congested.
  • Overall styling rather similar to the competition.
  • It is sometimes difficult to tell whether the buttons are up or down.

Though there are no confirmed plans for a fully automated version of this desk, the MIDI muting system as fitted is both versatile and well-behaved. Both the popular muting systems, snapshot (scene) and external sequencer driven, are implemented — ease of editing, as always, being dictated by the sequencer used. The security number feature is also a useful addition, and though there are relatively few number permutations, the console does lock up for two hours after three incorrect tries so it would take a lot of time and patience to hack it.

Ultimately, the P7 sounds good, is easy to use and appears suitably robust, the low cost having been achieved by sacrificing individual channel modularity — a route taken by most other budget mixer manufacturers. Critics might say that the P7 is rather too similar in appearance to the Allen & Heath GS3 or Soundcraft Spirit Studio, but this doesn't make it a less useful mixer. Indeed, it has one or two nice touches — such as the 2-track tape dubbing facility and dual monitor output — which are genuine bonuses on such a low-cost desk. Studiomaster should really have brought this desk onto the market a year or two ago, but given its performance and price, I think they'll win their share both of sales and satisfied users.

Further Information
Studiomaster P7 £2583.82; 8-channel expansion modules, £969,38. Prices include VAT.

Studiomaster, (Contact Details).

MIDI Muting

The more channels you have to mix, the less easy it is to handle fader changes, and some form of automation becomes desirable. MIDI muting is the simplest and least expensive form of automation and can be used to keep tracks completely quiet when no signal is present, or even, with a little imaginative patching, to switch one signal between two or more channels with different level, EQ or effects settings. MIDI muting systems are now well established, and the system on the P7 seems to be particularly well conceived, with 'soft' switching to avoid clicks when mutes are turned on or off. It is possible to set the system to run on any of the 16 available MIDI channels, or MIDI may be disabled if not required. With mutes on every input channel, every monitor channel, and four of the Aux sends, the P7 is well equipped to handle both routine and creative muting jobs.

In fact, the P7 offers two auto-muting systems: a more comprehensive MIDI system, which requires the use of a separate sequencer; and an on-board arrangement whereby the mixer can store up to 100 user-defined 'scenes'. A scene in this context is simply a recording of all the mute positions on the desk.

Each arrangement of mutes can be saved to one of the mixer's memory locations and then retrieved, as required, during mixdown. The system works well enough, though it's important to keep a careful record of exactly which scene is which. For the musician working alone, a footswitch option to step through the scenes would have been useful. A neat additional feature is the ability to store four scenes and recall these directly using the four Mute Bus buttons; this is a quick and convenient way of working when you only need a few mute configurations for a specific mix.

Though the scene system is more than adequate for those with fairly modest requirements, the user needing more complex muting arrangements and having access to a sequencer with a tape sync facility will probably find the MIDI system is a better bet. It is, in fact, possible to call up a scene by means of a MIDI program change command, but for anyone using a sequencer, a more elegant solution is provided. Every time a mute button is pressed, the mixer transmits a MIDI Note On message, closely followed by a Note Off. If the channel is actually being muted, the note will have a velocity value of 96; if it is being de-muted, it has a value of 32. This information can be recorded to a sequencer and, when played back, the mixer will respond to the note information by muting and de-muting the channels as required.

This system has certain limitations, however. Imagine a song in which a particular channel is open for the first half of the first verse and then closed for the rest of the piece. If the engineer starts the tape at the end of the first verse for a drop-in during the second, the note information muting that channel will be missed, and the channel will remain open throughout the take. To remedy this, the P7 also encodes the mute data into Controller dumps which are transmitted every second. These are also recorded to the sequencer and, subsequently read by the mixer whenever the tape is started.

In order to establish the current mute status. This controller information is only read for three seconds or so after the tape is started, after which the system reverts to reading note information. This is not dissimilar in principle to a sync box generating, and responding to, MIDI sync code with song position pointers.

Though the Controller data will be an exact replica of the note information when it is first recorded, it's conceivable that subsequent note editing would render the Controller data inaccurate in some way. Most of the time, this won't be a problem, but if editing is extensive, new controller information can be generated by filtering out the original Controller data on the sequencer and playing the note information back into the mixer. As it receives the note data, fresh Controller data and note information is generated, and this is transmitted back to the sequencer where it can be recorded onto a new track. The old data may then be deleted.

Also resident in the MIDI muting section of the desk is the SIP or Solo-In-Place facility. Pressing the master SIP button toggles the desk between SIP or Mute operation. When a Mute/SIP button is pressed while the desk is in SIP mode, all the other channels are muted, except for those protected by Solo Safe. Solo Safe allows signals such as effects to be made immune to muting so that, for example, using SIP on the guitar signal will solo the guitar complete with its true level, stereo position and effects. Unlike the AFL/PFL buttons, the SIP buttons cannot be used during mixdown without affecting the main output.


Mic Equivalent Input Noise: -128dB (A wtd)
Line Equivalent Input Noise: -93dB (A wtd)
Frequency Response: 20Hz to 20kHz +0/ -0.3dB (Mic or line in to any output).

Mute Switch Isolation: -106dB
Routing Switch Isolation to Groups: -94dB
Routing Switch Isolation to L-R: -81 dB

All EQ provides 16dB of cut or boost

HF: 12.5kHz; shelving
HMF: 500Hz-10kHz; Q=1.6
LMF: 100Hz-2kHz; Q=1.6
LF: 60Hz; shelving
Stereo Aux Returns
HF: 12.5 kHz; shelving
LF: 60 Hz; shelving

Mic: 2k ohm
Line: 10k ohm
Monitor: 180k ohm
Send/Returns: 4k ohm
2-Track Returns: 5k ohm

Also featuring gear in this article

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Marshall Arts

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Effective Reverb

Recording Musician - Copyright: SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.


Recording Musician - Apr 1993

Donated & scanned by: Mike Gorman

Gear in this article:

Mixer > Studiomaster > P7

Review by Mike Simmons

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