Mod Delay

A compact but feature-packed multipurpose delay line where the delay time can be modulated either with the built-in LFO or an external source. A time-modulated delay is the heart of several classic audio effects, including choruses, flangers, vibratos, feedback drones, multitap delays, lush reverbs... you name it. You can use Mod Delay as the fundamental building block to create your dream effects - the possibilities are endless, as they say!

• Watch a video to get an idea what you can do with Mod Delay!
• Download the presets used in the video (Copy the presets into a new folder under the User Presets folder. Note that the presets use mostly Cherry Audio's core modules with a few exceptions, like the DCO-60 synth and some modules from The Drift Pack, but you can demo and/or easily replace any modules you don't own.)

The numeric readouts for delay time, modulation rate, modulation depth and output level are always visible. This makes it easy to compare & set appropriate values in complex patches that use multiple instances of Mod Delay.

Basic operation:

• Connect the input & output cables to the jacks on the bottom.
• Set the base delay time with the TIME knob. The maximum delay time is two seconds.
• NEW: You can enable tempo sync with the little S button next to the delay time knob. When enabled, the delay time is set in musical units, from 1/64 triplet to 1/1 dotted notes. Voltage Modular's global tempo is used to calculate the final delay time.

Modulation:

• To use one of the internal LFOs, select either SIN for a sine wave, TRI for triangle, or RND for smooth random modulation. These are probably the most common modulation types for modulated delay lines. Set the modulation rate and depth with the corresponding knobs. Note that the random waveform does not really have a frequency or cycle per se, and the rate Hz value is there just to give you some idea of the LFO speed.
• To use an external modulation source, select EXT and connect any signal to the corresponding jack. Set modulation depth as usual, but note that the RATE knob is inactive when using external sources.
• For the internal modulation sources, the maximum modulation depth is one second. Note that the modulation is bipolar, so at maximum depth, the modulation range is 500 ms to both directions from the base delay time. This also means that the average delay time will be rhythmically correct when tempo sync is enabled (as long as the modulation is not too large to "touch the edges" - see below).
• For external modulation, the regular -5 to +5 volt range corresponds to the range set by the DEPTH knob, but of course the incoming signal can also exceed these limits.
• If the modulated delay time "hits the walls", meaning it either tries to go below zero or exceed the maximum delay time of two seconds, the corresponding MIN or MAX led will light up, and the modulation will be clipped. In that case, you might want to turn down the modulation depth, and/or move the base delay time towards the center of the two second range. You can also enable the AUTO button, which automatically adjusts the base delay time when necessary, so that the modulation range is never clipped. Note that with external modulation, AUTO only works as long as the modulation signal stays between -5 and +5 volts.

Output:

• Trim the output level with the LEVEL knob, from 0 to 2x.
• You can invert the phase of the output signal with the corresponding button.
• Choose between two quality modes: HQ disabled means linear interpolation is used for the modulation, which is very easy for the CPU and still sounds pretty good in most situations. HQ enabled uses four-point polynomial interpolation, which sounds very good but uses slightly more CPU.

Tips:

• Use multiple instances of Mod Delay to build interesting and complex effects!
• Try different ways to connect delays to each other and to other modules. Combine parallel and serial connections to build delay line networks, and be sure to (ab)use feedback loops. (As always, be careful with feedback - it’s easy to make things blow up! Use safety limiters and turn the volume down when trying new settings & connections.)
• Combine delays with filters and other modules.
• For chorus-type effects, try small modulation depths like 1-5 ms. For more outlandish effects, feel free to go bigger!
• Use tempo sync to build "traditional" rhythmic delay effects. You can build complex multitap delays with multiple Mod Delay instances. Add some modulation and cross-feedback, and things can become very interesting...
• Sine modulation also produces sine-shaped pitch modulation, while triangle makes the pitch jump between two values around the original pitch. In more generic technical terms, when modulating the delay or phase of a signal, the resulting pitch modulation waveform is the rate of change or derivative of the delay modulation waveform.
• If you want more control over the modulation (for example, modulate the modulation rate), remember you can always use an external LFO and make it as complex and flexible as you wish.
• While delay lines are typically modulated with LFOs, you can of course use anything for modulation, including audio rate signals, which means you can use Mod Delay as a kind of FM module...

And as always, have a great time!