Intelligent Devices Marshall Time Modulator review

  • $149
The Marshall Time Modulator will complement rather than replace your existing plug-ins.

MusicRadar Verdict

MTM's excellent vintage emulation hits the spot, making it a great complement to modern delay and modulation effects.


  • +

    Rich flanger effect. Clearer layout than original. Powerful feedback capability. Useful LFO shapes. Good panning options.


  • -

    Currently VST-only. No host tempo sync.

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The Marshall Time Modulator is a classic analogue delay and modulation unit from the mid-'70s. Designed by the late Stephen St. Croix (aka Stephen Marshall), it became popular for its ability to produce deep flanging and crazy modulations.

Now available for Mac and PC in VST plug-in form (with AU/RTAS to follow), Intelligent Devices aims to deliver all aspects of the original coupled with typical plug-in features such as stereo operation. And with St. Croix's involvement with ID being well documented, you know that this plug-in is 'the real deal'.

In detail

Fundamental to the design are twin delay lines, dubbed A and B, coupled to modulation. The delays always retain a ratio to each other of either 1:2 or 1:4, depending on which of the six timing presets you plump for. These determine the range of delay times that can be dialled in with the Time Delay control.

So, for example, the first preset gives delay line A times between 0.2ms and 12ms, while delay line B will range from 0.4ms to 25ms - note that the ratio is (more or less) 1:2. The first three presets are short, 'flanger' settings while the others give a noticeable echo effect - the longest delay available is on line B (400ms).

MTM's other key feature is modulation, adjusted via an LFO (0.1Hz to 10Hz) linked to a parameter called Time Mod (0 to 100%). With the latter cranked to its maximum setting, the delay time is modulated between the limits of its preset, while reducing it causes the delay time to 'gravitate' towards the value set with the Time Delay knob.

Finally, to round things off, there are controls for delay feedback amount, input/ output levels per delay line and wet/dry mix.

New features

In addition to the improved layout and signal flow view, the MTM's plug-in extends the original's stereo capabilities and LFO options.

The plug-in comes in mono, stereo and mono-to-stereo configurations. The stereo options enable you to individually pan and phase reverse the delay lines, adding considerably to the effect's potential. A panning control for the input signal acts as a left/right control in the mono-to-stereo plug-in and as a stereo width control in the full stereo version.

The LFO includes not just the original's sine and square waves, but also saw, triangle, random and 'SSC' (Steve's own custom shape). As you might imagine, the extra waveforms add new flavours to the MTM sound, particularly when combined with the stereo and phase reverse options.


The Marshall Time Modulator is a pretty individual animal, but the layout of the plug-in assists considerably in understanding it. The bottom third of the screen features typical knob controls and the top two thirds replicate the majority of this in signal flow form. What's more, you can make adjustments in both areas.

The MTM plug-in is undoubtedly easier to comprehend than the oddball original, but the esoteric sonic nature of the hardware is intact. You can easily achieve thick, sweeping flange effects or pitch-modulated delays, then switch delay times and find yourself swamped in speaker-mashing feedback.

This is all part and parcel of the original design, and achieving a fine balance between delay time, level and feedback is the key to taming the beast. Beyond this, added features such as channel phase reverse and panning enable superb ethereal, spacious effects. MTM also excels at creating crazy spot effects from single impulses.

MTM isn't a replacement for typical delay or modulation effects, and you'll probably find the lack of host sync for either the delay or LFO mildly annoying, Nevertheless, it's great to see such a classic resurface in plug-in form.

Hear the Marshall Time Modulator in action:

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