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Review of 4ms PEG add-on for Softube Modular



The 4ms PEG is an add-on for Softube Modular virtual synth. It is not a standalone VST and requires a modular licence to run. Typically priced at $29, the 4ms PEG is available from Softube and a 20 day demo is also available. It is fully licensed and endorsed by 4ms, manufacturers of the original hardware.

I have previously reviewed Modular which you can read here, it’s an excellent software version of a modular system which is very easy to use and has superb sound quality.


The 4ms PEG is a brilliant addition to Modular, it is a faithful recreation of the original hardware unit. The potential is huge, you can go far beyond conventional envelopes to create complex patterns, quantised beats, self-oscillation and much more. It’s brilliant fun to play around with, it encourages experimentation to see what happens and that’s when you find some very cool and unexpected sounds.


The 4ms PEG is a dual envelope generator whose envelope lengths are set by the time between clock pulses or “pings”. The PEG has full CV control of envelope shape, skew, and ping (clock) division/multiplication, as well as a plethora of triggering and cycling options (AD, AR, quantization, cycle, cycle toggle), and a tap tempo button for each channel.

The basic setup is a ping, a trigger source and an output.


The ping can be provided by tapping the white button next to the red or blue ping inputs at the top of the display or an external source can be fed into the jack.


You press the cycle button to start to the trigger which subsequently changes colour to yellow and the LED above the ENV jack also starts flashing. You can also run manual triggers into the QNT (Quantised) or ASYNC (Asynchronous) jacks. Feeding a gate into the ‘T’ jack toggles the state of the cycle from off to on or vice versa. This means you can toggle between the two channels or switch them on/off at the same time.


The scale knob provides your output, the bi-polar switch focusses the output around 0v. There are two outputs, ENV is scaled whereas ‘+5V ENV’ is unscaled,

Once the basic setup is completed, you can start to change envelope parameters. That’s when things start to get very interesting.


The ping div/mult knob is an integer multiple or division of the original tempo in steps from parity to +/- 8 times. This can be modulated using the DIV CV jack at the bottom.


The curve knob sets the envelope shape. The curve knob has asymmetrical curves at the extremes and symmetrical curves in the middle. These are formed by combinations of exponential, linear and logarithmic waveforms and there are 17 in total. You can modulate these parameters using the Skew and Curve CV jacks located at the bottom of the display.

The skew knob controls the ratio between the rise and fall times. The envelope length is held constant whilst the skew is changed allowing you to change between ramp-up, ramp-down and triangle – and everything in-between – without affecting the timing. Because the change is instantaneous, you can get some interesting outputs.


Each channel also has two gate outputs, End-of-Rise (EOR) and End-of-Fall (EOF).

EOR outputs a gate that goes high when the fall segment begins, and goes low when the envelope completes. It is low during a sustain segment. It will stay low when the envelope is not running.

EOF outputs a gate that goes high when the fall segment ends and goes low when a rise segment ends. It is low during a sustain segment. It will stay high when the envelope is not running.

The OR output acts like a mix control, outputting the highest value from either of the red or blue channels.

The 4ms PEG in use

There are many ways to use the 4ms PEG, I was very keen to use it with the Buchla 259e add-on (included in the aforementioned Modular review) because it produces a huge range of incredible sounds.

I found a video on YouTube which shows details of modules and patching connections that I’ve used as a basis to get me started and is shown below. I created this basic setup in Sensomusic Usine Hollyhock 3 and created a demo track with no external effects which is called ‘meridians – origin’.

I then thought I’d take a minimalist approach using this as the only sound source, add 4 send/return effects and AudioThing’s Type A as a pre-master to see if I could create a full sound and also a variety of sounds. I used an iterative process where I changed effects / effect settings and also changed settings on the Buchla 259e and 4ms PEG and then re-recorded. Recording in Hollyhock 3 is direct to disk so all of the tracks were recorded live and subsequently mastered in MuLab with Elevate and Stage.

The send effects used for the intro track were Amalgame, RP Verb 2, Ultratap and SpecOps. I’ve used combinations of various Eventide effects on other tracks – Ultratap, Blackhole, Fission, H3000, Quadravox, H949 and Octavox. On the last four tracks I also used the UDrone sampler in Hollyhock 3 with combinations of Ultratap, SpecOps and Blackhole.

The album is embedded at the start of the review and as you can see, I got a bit carried away. That’s partly due to how good Modular and the Buchla259e / 4ms PEG add-ons are and also the creativity offered by Eventide effects and some of my other favourite effects. The 4ms PEG just encourages you to tweak settings and see what happens and then you want to adjust the Buchla 259e settings, then tweak the PEG a bit more and what happens if I turn this all the way up or down? – it’s addictive. I’ve produced a whole range of sounds covering drones, ambiences, rhythmic glitches, harsh metallic sounds to more extreme experimentation.

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