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Stop the pattern and open up the waveform of your recording.

Make sure your editor is set to view and edit your waveform in samples rather than absolute time.

Zoom right in on the very front of a waveform (any of them will do) and place a marker - do it at the absolute maximum magnification on screen so you are certain the marker is where the waveform begins.

Now zoom back out and locate the very next waveform in the recording and again, zoom all the way back in and place another marker at the very start of this one too.

Repeat this for at least 8 of your recorded 'clicks' in the recording - 16 is better if you have the patience.

Now 'select' the block between the first two markers - usually clicking in the area with the mouse does the job.

Somewhere on screen the number of actual samples between your two markers will be indicated.

Write this number down.

Repeat this for each 'block' between all markers you have placed.

At 120 BPM - a perfect quarter note interval recorded at 44.1 kHz is exactly 22050 samples.

In a perfect world all your measured 'blocks' should be 22050 samples in length.

They won't be.

The amount the quarter note intervals vary will indicate how tight your sequencer or drum machine really is.

The bigger the variation, the sloppier the rhythm.

Two things obviously affect this measurement - the real tempo (as opposed to what it tells you on the screen) and jitter (tempo fluctuations). What is critical is the amount of variation you find in your measurements. If your blocks vary by more than 50 samples then the device's ability to keep tight rhythmic time is questionable at best. Remember that our test is very easy on the hardware and software resources - a single track of well spaced events. There are no polyphony or multitimbral compromises to hide behind.

Sequencer Tempo Jitter/Event Slop has two primary causes - Clock Jitter (where the clock driving the internal sequencer or slave device is a bit rough) and Internal Event Trigger Lag (where a devices ability to correctly trigger an event referenced to the tempo grid/clock position is compromised in someway leading to push-pull within the device itself).

The end timing performance stability in any sequencing system is a combination of both these factors.

Bear in mind also that these test results are the very best your box or software application can produce. Under more normal usage you will usually find things get much worse.

Published hardware and software specifications in owner's manuals, on-line and in the glossy brochures and print media focus almost exclusively on the myriad of bells and whistles on offer. The aim being of course to tempt and tease in a bigger, faster, wider, louder, and 'newer is better' display of spec-superiority - polyphony, memory, number of patches, high sample rates, track count, plug-in support, data I/O speed, CD Burning etc.

What they never publish or even mention is timing performance.

I'm still uncertain if this is a deliberate strategy to hide poor design, that R&D teams dismiss the notion that humans have a very high degree of sensitivity to rhythmic variance or that the marketing departments find this area of analysis just too dry and uninteresting for the general public.

These days it would be my first consideration before buying anything at all.

You can spend as much as you like on furnishings and fancy wallpaper but a house is only as good as the foundation it is built on and in sequencing the foundation is the clock.

After your own tests are completed and the numbers don't look so crash hot - tell the manufacturer.

Email them the numbers and tell them you expect better.

Let them know you would prefer a tight sequencing engine with a few less frills not an expensive rubber band with everything and the kitchen sink included.

[On a recent forum regarding sequencer timing stability - the audio/DAW method of measurement as outlined here was strongly critisised as being too inaccurate to be considered meaningful when measuring tempo jitter in sequencers. For those of you reading this with similar views I thought it important to quote a direct reply from one of the design/R&D team involved in the product in question: ' There is nothing wrong with your method of measuring the jitter, any fully working sound card will do.']

All In Good Time

It seems logical to my mind that time is the core foundation on which all music is created because what makes sound into music is how the sounds are played or replayed in time.

There is a common belief that certain sequencers and drum machines have a magic ‘groove’ or feel built right into them. I personally don't think there is any 'magic' beat box feel - vintage or contemporary. What gives any rhythmic pattern 'feel' is how we anticipate where sounds fall in time and because every individual hears subjectively it makes practical analysis and criticism of timing performance in sequencers very difficult. This I well understand.

I do believe strongly, however, that adding any random element to step/event placement in any sequencing device does not create feel. All it serves to do is blur the edges.

The exact opposite applies when deliberate push-pull placement of steps and events against a strict, quantised tempo-grid is used to customise rhythmic feel - pushed hats, late snares and of course added amounts of shuffle/swing.

Discussions about timing precision in music always invoke passionate debate and there are many who see any quest for tighter performance as an obsessive desire for extreme rigidity and control. The assertion being that this is a very negative characteristic and that ‘going with the flow’ and accepting some element of ‘human-feel’ is a far more musically appealing way to be.

Rigidity has negative connotations for most musicians but I must stress again that a desire for precision and consistency in sequencing is not about rigidity or stiffness at all. Quite the reverse in fact.

Feel is rhythmic anticipation – and that very human anticipation relies on the strict principle that if a snare is deliberately placed 5 ticks late it must always sound 5 ticks late to faithfully maintain the groove. The potential feel in any rhythm becomes less focused when the snares fall 3 ticks late sometimes and 7 ticks late other times in a pattern or loop when the timing variation is of a random nature.

It is important not to confuse random timing errors with any concept of human feel.
It is not feel in any sense because the timing variation is random.
It is simply software and hardware not keeping time.

The Good, The Bad and The Lumpy.
As I get around to it I will list here my measurements on various boxes and software sequencing applications.

All tests as specified above - 120 BPM recorded at 44.1 kHz into Soundforge 8 or Soundforge 9.

The group of measured consecutive quarter note intervals will be listed in samples along with a maximum variance between any two.

On first inspection it may seem that measuring the error margin away from the theoretical 'perfect' grid value of 22050 is a more accurate way to look at these numbers, however, our perception of feel is all about how our brain interprets the length of time BETWEEN consecutive rhythmic events. This is why the push-pull timing of consecutive events is the most significant set of numbers to consider when looking at sequencer timing stability.

Date of test and current Operating System is listed.

Obviously a change of OS may mean a change in test results.

Equipment listed is in no order of personal preference.

Feel free to email me if your own testing provides a different set of numbers.

Remember that this is a highly biased rating system based on one feature only. Important as timing performance is, there are many other aspects to software and hardware sequencers that contribute their overall worth as creative tools.

My genuine wish is that the designers and manufacturers of our current and future music machines start placing timing performance at the very top of the priority list when it comes to features and OS updates they offer.

At the end of the day it comes down to sales. If we continue to buy our toys and tools as they are then there is little incentive for the manufacturers to change anything. If enough customers began refusing new drum machine, sequencer, groovebox and workstation purchases based on this simple test and let the company know the reasons why then I think accurate timing performance might soon become a much higher design priority than it is now.

Email: info@innerclocksystems.com

Originally, this page included devices still current and in production at the time of testing. The motivation for the Litmus testing was not to cause any individuals or organisations grief but simply to provide reliable timing information to those who wished to know. There have been some that view this page as detrimental to companies that manufacture products that rank low on the timing stability scale. There are also some that have actively suggested on a number of forums that this page is simply a way for me to generate Sync-Shift sales. For those that understand the design of the Sync-Shift this notion is ridiculous.

The Litmus Ranking scale indicates Event/Tempo Jitter within a device itself. If a sequencer or drum-machine has internal coding or hardware issues that cause timing irregularities, then no amount of Sync-Shifting will cure that. The Sync-Shift is a Start-Offset device. Nothing more and nothing less.

Nevertheless I have decided to make the Litmus Page restricted to devices no longer in current production. If you wish to test current products yourself, the method listed above holds true.

One exception to this is the Mansell-Labs Vailixi OS Upgrade for the Akai MPC-3000 which deserves a special mention. Even though Akai's production of this fine instrument ceased some years back, Rohan Mansell now offers a custom OS Eprom System set that refines Roger Linn's original vision further by adding a number of very valuable features without sacrificing any aspect of the core design and performance that make the unit so special to this day. If you own an MPC-3000 - visit the website and get the OS Upgrade. If you don't own one and you have an ear for timing - find one, buy it and then get the Vailixi Upgrade. You will not regret either purchase I assure you. A truly remarkable achievement in every respect.