Reverb is an electronic effect which gives any sound signal the illusion of reverberation. Spring reverb does it by electromechanically vibrating one end of a set of springs in a tank, then recording the vibrating strings to create a pleasantly “wet” metallic ringing.
Behold my happy little Belton spring reverb tank, ready to be patted soothingly.
This short ambient piece was made using a spring reverb effect, but it’s not actually reverberating anything except itself. I sent its output back into the input to create a feedback loop. This made the springs ring uncontrollably after a few seconds, but I can mute the springs with my fingers to quieten them down.
There’s been a bit of reverb and delay added afterwards to space it up a bit. 🙂
This is a jam for anyone who enjoyed the harder house tracks like Rollin’ and Scratchin’ or Rock’n Roll on Daft Punk’s album Homework. It’s a spiky glitchy drone with some nice polyrhythmic percussion and that’s it – maybe not everyone’s cup of tea but I like it. 🙂
Tech notes
I used two of my new modules for this! The Music Thing Modular Pulses mk 2 is outputting a randomly generated six note rhythm tapped at two points for the clap and the hi-hat. The modulation state of the drone is being sample-and-holded in sync with a Euclidean rhythm out of the Little Nerd. The drone is feeding into the Voltage Control Lab VCF-74 Mk 1 where it’s being frequency modulated; that’s fed into a Ladik Waveform Animator then on to the Eowave Fluctuations Magnetiques filter bank through a parallel low-pass and band-pass filter.
The drone is just sitting at one steady note. So why does it sound so lively? The experiment was to see what would happen if I put a pulse wave through a low pass filter and then put that through the waveform animator. The animator only works on waves with gradual transitions which means a pulse wave goes in and out unchanged, but a low pass filter can introduce those transitions into the pulse wave by filtering the sharper frequencies away to make it transition more like a sine wave. The texture of the drone comes from crazy chaotic interactions between the filter frequency modulation, the waveform animator and the pulsewidth of the original oscillator.
I bought a couple of new Eurorack modules recently and wanted to try them out. Here’s the Chronoblob rippling an arpeggio across the fabric of spacetime with the help of the Deflector Shield in the aux path. Press play to travel through outer space or download here.
I got an Expert Sleepers Disting Mk 4 module on Friday. It is Eurorack’s designated swiss army chainsaw. Amongst its 76 modes, it can be a vocoder. I took it for a spin with a John Cage lecture as the modulator signal on Friday evening and the above is what came out.
Analogue and analogue-style vocoders are a system of band-pass filters, envelope followers and amplification. Two signals enter the vocoder: a carrier signal which supplies the timbre of the output sound, and a modulator signal which supplies frequency and amplitude information.
A bank of band-pass filters cut each signal into strips of frequency (think bass and treble, but much more precise). The vocoder tracks how loud the modulator signal is at each strip, then adjusts the volume of the carrier’s strips to follow the modulator’s strips. The carrier’s strips are combined back together as a whole signal and out comes Cylons.
One of the challenges with vocoders is getting output that’s as intelligible as the input. The intelligibility of the Mk 4’s vocoder was not great, so I mixed in a filtered version of the original speech. The filter is tuned to sibilant sounds (like s, f and th) which were getting lost in the vocoder process. It’s an old trick – the EMS Vocoder used for the Cylons has a cleverer version which lets sibilance through as it’s required – but a dumb version works in a pinch and as a result you can understand Mr Cage just fine.
For further fun, I’m modulating the pitch of the carrier signal with a random signal. This makes Mr Cage sound much more floaty than usual as the carrier floats up and down in pitch, giving him a rather more vague delivery.
The original sample is a snatch of the Mercury Theater’s infamous “War of the Worlds” broadcast, looped to twist its meaning. The chief glitch mangler effect here is a PT2399 digital delay chip living inside the Befaco Crush Delay v2. Its delay length is being automatically modulated by four stacked modulation sources – two random, two cyclic – via a Befaco A*B+C attenuverter/offsetter. The strength & offset of the delay modulation and feedback strength of the delay were manually manipulated during the recording.
