Reprinted from the September 2002 issue of Sound On Sound magazine (UK)

Roger Linn Design AdrenaLinn
Roger Linn Design AdrenaLinn Filter, Effects, Amp Modeller & Drum Box

By Paul White

AdrenaLinn is the first product from Roger Linn Design and was designed by a team that includes Roger himself (inventor of the LinnDrum) and Dave Smith, ex of Sequential Circuits and probably most famous for conceiving the MIDI protocol. Roger Linn is actually a guitarist and so invented this box because he thought it would be fun to have one, but the AdrenaLinn can also be used to process synths, drum machines and just about any other sound source you care to feed into it. So what exactly is it?

The AdrenaLinn is essentially a mono-in, stereo-out effects processor in stomp box format but is unusual in that it includes a simple drum machine based on two bar measures, a modelling guitar amplifier of the type we're all now quite familiar with and a sequencer-driven filter section with up to 32 steps that can work in sync with the drum machine. Alternatively, the whole machine can be locked to MIDI clock for full integration with a MIDI sequencer. Though it is possible to create traditional filter effects such as wah and flange, the real reason for AdrenaLinn's existence is its ability to create stepped rhythmic filter treatments. The effects on offer include synth sample-and-hold style sounds, rhythmic tremolo patterns and tuned flange patterns that pick out a musical scale from any wide spectrum input, including percussion, and other rhythmic treatments.

The signal path can route the filter into the guitar amp model, like a traditional wah wah, which is always placed before the amp, or you can switch it and feed the guitar amp into the filter, which gives the filter more to work on if you're using an overdrive model. The output of this combination then feeds a separate delay unit, which may also be tempo locked. It's also possible to feed the drum machine through the amp/filter section as well for some seriously cool and grungy rhythmic effects, and to get started there are 100 preset drum machine patterns plus 100 preset effect treatments with space to add another 100 of each of your own. A number of pattern swing options are independently available to the drum machine and filter sequencer which not only extends the usefulness of the factory drum patterns significantly, but it also opens up rhythmic opportunities for combining a drum part of one feel with a filter sequence of a different feel.

Editing is accomplished by a fairly simple matrix system where rows of parameters are addressed via knobs at the top of the rows and selected by means of buttons down the side. Owners of Emagic's SoundDiver can also download an editor module free of charge (both Mac and PC) from www.rogerlinndesign.com, which brings all the parameters out to a screen of virtual sliders. This is useful, because while editing from the front panel is not actually difficult, it can be time consuming.

The Box Housed in a blue cast metal case, the AdrenaLinn has a rear printed laminate front panel which is very tough as well as being attractive and easy to produce. This also provides a window for the three character LED display which shows patch numbers and parameter details when editing. The in and stereo outs are on unbalanced jacks on the rear panel and power comes from an external 7.5v power adaptor. MIDI connectivity is in the form of MIDI In and Out connectors. A trim pot and clip LED on the front panel allow you to match the input gain to your instrument, though I found there wasn't enough gain to get the clip LED to come on at all with my Strat.

The control surface comprises two footswitches, four knobs and five buttons where the footswitches are generally used for rhythm start/stop and bypass. Pressing and holding the Start switch when the machine is stopped provides a one measure count-in whereas if the machine is already playing, it stops at the end of the current measure. Holding down Bypass works as a kind of inverse tap tempo where the tempo is set by holding it down for one measure.

The four knobs select the Preset, Drumbeat, Tempo and Volume as their main function but pressing and holding the Main button switches them to a second mode (denoted by printing beneath the knobs) that's most likely only to be used when setting up. The first knob defines the way Bypass works, which can be as a conventional bypass or it can be made to switch between the current and newly selected patch. There's also the option to restart the current measure for situations where you're playing without sync and may occasionally need to manually sync the measure start point to whatever you're playing along to.

Next is Dir-Amp/Gate, which allows the selection of four options. Dir provides a speaker simulated output for feeding a PA or recording system, while Amp switches the simulator out. The remaining two options are the same but with the inbuilt noise gate disabled. This can only be on or off - it has no user adjustments. Knob three is labelled Use Drumbeat Tempo and decides whether AdrenaLinn follows the tempo of the loaded patch or whether the last used tempo will be used for all patches. Finally comes Balance/Sep, which sets the relative balance of the drum machine section and the amp/effects section. A useful touch is that moving the knob past the position where the display shows d50 sends the instrument to the left output (in mono of course) and the drum machine to the right.

Try it Now!
To try the machine in 'instant gratification' mode, all you need do is use the four knobs to select the drum and effect patches, set the tempo and adjust the volume. Editing patches isn't too scary as all the parameters are shown in the printed matrix on the front panel and are neatly sectioned into Preset, Drum Beat and MIDI areas. Nevertheless, you do need the manual at first to remind you what the abbreviated parameter names that crop up in the display actually stand for. The two buttons to the left of the rows step up and down through the rows as indicated by status LEDs at the start of each row and turning the knob above the parameter name in the illuminated row makes the adjustment. The same two buttons are used as effect and drumbeat store buttons by pressing and holding them. This allows you to select a user memory into which to save the settings, after which you push the button again.

The effects are based around filter types that can change their parameters for every step of the 32-step sequence and six filter types are available. The first is a (variable) resonant low-pass, 12dB/octave synth style filter while filter two is a 24dB/octave synth filter reminiscent of those used in vintage Moog instruments. Then come normal and inverted flanging, pitch modulation and finally volume. By adjusting the volume of each sequenced step, extremely rhythmic gating effects can be set up and the easiest way I found of doing this was to pick a rhythmic tremolo effect and then edit it to control the volume via MIDI Note velocity. All you need do then is create a line of 16 or 32 consecutive MIDI notes in your sequencer edit page and then turn the velocity full up on the beats you want to be loud and down on the beats you want to be quiet. Loud beats will continue until a low velocity note is encountered, so it is essential loud notes are separated by quiet notes. When you have a pattern you like, you can loop it.

Moving on to the amp modelling section, this includes 12 models based on all the classics that just about every other amp model seems to include (famous UK and American amps plus a couple of high gain specials, a fuzz box and lean DI sound). The variable parameters for each model are Drive, Bass, Middle and Treble.

The delay section is fairly conventional but can again be set manually up to one second of delay or linked to the sequencer with delay times from half a measure to 32nd note triplets, within the limitation of the maximum delay time. A variable feedback parameter sets the degree of repeat and the delay level can be controlled relative to the main signal.

Filter Tips
What makes the effect interesting is the way in which the filter frequencies can be modulated, and each can be controlled by the sequence, by an envelope generator, an internal LFO, the audio envelopes or the peak
(held) level or by five external MIDI sources (Note, Velocity, Bend, Controller or MIDI Pressure). Additionally, several of the modulators can themselves be modulated by other internal sources or external MIDI parameters.

Rhythmic filter effects are based on filter sequence (each sequence can comprise 16 x1/8 notes, 24x 1/8 triplets or 32x 1/16 notes) where each step can have a modulation value from 0 to 99 in addition to the ability to trigger the envelope generator when the sequencer moves to that step. A secondary mode of the edit matrix is used to edit the filter sequence and is accessed using the Sequencer button after which L shows in the display indicating that levels can be adjusted. Pressing Sequencer changes the display to Eg showing that the envelope generators are being edited. Selecting Eg0 disables the envelope for the current step whereas Eg1 means the envelope will trigger at the current step. The modulation envelopes have variable attack and decay or release depending on which mode is selected while the LFO has four waveforms plus random. The LFO rate can be set conventionally or related to the sequence tempo ranging from one cycle every eight bars to one cycle every 32nd note triplet in a number of steps.

A further alternative mode of the edit matrix is used to edit the drum beats in step-time fashion, which are based on a library of 40 drum samples that can be arranged as 8, 12 or 16 note measures with various degree of swing. Most drum voices are played at a fixed level (the kick, snare or hi-hat note can play at one of three volume levels) and there's no means to chain patterns, though the machine can play basic intro patterns. This is a simple beat box to play along to but it has an excellent feel and is capable of producing some great sounds that would make fine sample loops.

MIDI
Using MIDI, the internal tempo can be locked to incoming MIDI Clock along with Start, Continue and Song Position pointer capability. Alternatively, AdrenaLinn can send MIDI Clock to its own output. The MIDI setup allows MIDI to be selected as an envelope trigger source, with or without program changes and there's also the facility to dump or load patches via MIDI, either as drums plus effect preset or separately. The most exiting aspect of MIDI control, other than keeping things in time, is the ability to control effects in real time using MIDI patterns stored in a sequencer.

In Use
The real question is: is AdrenaLinn likely to increase your heart rate, and the answer really depends on what you want to get out of it. As a drum box, it is a little simple by today's standards, good though it sounds, and similarly the guitar modelling is quite proficient, but it lacks reverb or ambience so you need to add this some other way. I also found the amp models to be noisier than expected, even when little or no overdrive was being used, and the noise gate isn't always effective in hiding this during note decays, especially as it can't be adjusted. Noise was not a problem when creating filter effects as the filters tend to clean up the sound quite dramatically (or in the case of tuned filters and flangers, the filtered noise becomes part of the effect), and when separating the drum and guitar outputs, the drum machine output is quite clean.

AdrenaLinn isn't really about drum boxes or amp modelling - it's about creating rhythmic filter and tremolo effects that you can't get easily by any other means. We've all heard those great rhythms you can get by patching the output from a drum machine into the side-chain trigger input of a gate, then using it to chop up guitars, but AdrenaLinn takes that kind of concept much further. The tuned flange, for example, imposes a recognisable musical scale onto anything from damped guitar to drums, and by setting it to trigger from external MIDI notes as in patch 98, you can use a sequencer to make it play anything you want to. The sound is hard to describe but has that 'tearing' quality of synth phase sync. Even if you never program your own patches, the fact that the factory menu includes some MIDI triggerable tricks means you can still get the effects to match your sequencer songs.

The other fun thing is to feed the drum machine through the effects section where it can be distorted and filtered in a variety of ways, producing the kind of results you normally have to buy a sample CD to achieve. Because the drum beats are so easy to customise, you can create any number of precisely tailored down-and-dirty sample loops from a machine that costs around twice the price of a typical sample CD-ROM.

Though rhythmic effects are what AdrenaLinn does best, the factory patches include 20 straight ahead guitar amp models plus effects. These have a good dynamic response, though you will need to add reverb somewhere along the line, but because of the background noise issue, I don't think I'd use them for recording conventional guitar parts without the aid of a dynamic noise filter (single-ended noise reduction). Turning down some of the generous high end on the amp model EQ controls helps somewhat, but not really enough.

The stand-alone modulation effects, ranging from rhythm locked filter, flanger and tremolo treatments to rotary speakers and auto-pan, fare much better (they are much quieter), so for the most part, the AdrenaLinn makes a good general-purpose audio tool kit in addition to its rhythmic filter and beat box capability.

Summary
If you just want to play guitar, AdrenaLinn may not be quite your bag, but if you're the kind of person who loves rhythms and likes experimenting, then you can get a lot out of it, whether by modifying presets or coming up with your own unique patches. I enjoyed using with it so much that despite some criticisms, I bought one. Just playing around with the effects stimulates new ways of thinking about rhythm and composition, and just about any sound source can be turned into something interesting. OK, so the fixed threshold noise gate is limiting and the amp models used without the filters are on the noisy side, but noise isn't a problem when using the filter effects, the modulation effects or the drum output on its own. It would also be wrong to underestimate the usefulness of the drum machine, because even though you can't chain patterns or create songs, it is superb for creating powerful grooves that really swing, and it's easy enough to overdub additional parts using your sequencer.

AdrenaLinn is a unique effects box and has lots of creative applications both live and in the studio. My own view is that when people actually get what it's about, it will quickly establish itself as a cult product that will be much talked about in the years to come.

PROS
* Unique rhythmic filter and gate effects.
* Includes a surprisingly useful drum machine.
* Affordable - a true impulse purchase.
* Can be sync'ed to MIDI and controlled from MIDI sequence data.

CONS
* Amp models are noisy when used alone.
* Editing from scratch can be long winded.

SUMMARY
Using an AdrenaLinn is a great way to dig yourself out of a musical rut and should appeal equally to preset bashers and nerdy programming types.