Patch Tips #10 - Pre-Decay

Mixing envelopes to emulate a reverb pre-delay.

Here's a very simple patch I use to change the impact of a sound. Mix a short negative voltage envelope with your main envelope to duck a portion of the attack phase. If you get the timing right, it can sound like longer pre-delay settings on a reverb:

predecay.mp3

In this patch, I used a Doepfer A-143-1 for its built-in polarizing mixer, triggering both envelopes with the same gate, but any combination of envelopes and mixer would do. You could of course also do the reverse and, using a positive envelope, add a second attack or 'bite' (e.g. trumpets) or flutter (claps) to a sound. See the A-143-1 manual for more ideas.

4MS RCD update & SCM preview

An overview of the updated 4MS Rotating Clock Divider and a taste of the company's next product, the Shuffling Clock Multiplier.



I liked the RCD when I first tried it, but missed the ability to output gates and, more importantly, wished it could count on the downbeat. This latest update delivers both features and makes the Rotating Clock Divider perfect.

Here are some short examples:



Downbeat counting. /1, /2 & /4 outputs drive three envelopes, Pressure Points rotates.



Similar to the above, but with gates rather than triggers.

This third recording demonstrates an interesting side effect of the way the RCD generates its gates in upbeat mode: the /1, or mult of the source clock, is inverted, resulting in a funky offbeat. The first half of the clip is upbeat the way we know and love it from the A-160 (source plus /4), the second half is the RCD. If you want a 'normal' upbeat division to play against your source, take the mult directly from your clock rather than the RCD.



Upbeat + Gate. A-160 then RCD.

I've been very lucky to have had the beta versions of the Shuffling Clock Multiplier and SCM Breakout for testing. In the past week, I've had so much fun twisting rhythms that I'm sad to have to send them back. The final feature-set and layout will likely change, so I won't go into any great detail. Suffice it to say, that rotating, shuffled clock multiplications are an even bigger hoot than divisions.

The SCM takes an incoming clock and multiplies it. These multiplications are available at separate outputs and, like the RCD, these can be rotated. The x4, x6 & x8 clocks have twin outputs, and these can be played off against each other for swing and drop-out effects. Lastly, you can also modulate the pulse width of the resulting gates.

Here are some examples of the key functions:



Left = x4, right = S(x4). Slippage altered first, then shuffle, then both. These functions are related: one determines the amount of swing, the other which beats are swung.



Same as above. Skip selects which beats are 'dropped'.

For more details on the SCM see the 4MS website and Youtube demos.

The breakout module is key as it gives you manual and CV access to these functions and, as you can tell from this final recording, makes the SCM a very playable instrument:

4ms SCM jam by navs

Two VCOs, SCM, quantizer, analogue shift register and a couple envelopes and VCAs. Sequence sent to VCO1 (left) and multed to the ASR which is clocked by the S(x4) output. The shifted clock and pitch information is sent to VCO2 (right). Manual tweaks of the clock, SCM, ASR output and quantizer scale.

Thanks to Dann of 4MS for the updated RCD - I can't wait to get my hands on the final SCM!

Clash of the Borgs

A quick comparison of the Malekko Wiard Borg 1 & 2, also featuring Plan B Models 12 & 13.



The Borg 1 (white knobs) employs slower vactrols, allegedly giving it a mellower sound and longer decay than the more aggressive, black knobbed Borg 2. I'm a big fan of the Plan B Model 12, but sometimes find it's response to CVs either too linear or lazy, so I was keen to hear the Borg 1 for myself.

Here's a fairly representative recording of the difference between these filters:


(Borg 2, Borg 1, Model 12)

I really liked the Borg 1's soft edges and muted tones. Its response is slower than the Borg 2 and this makes it a more natural sounding LPG. It might even have the edge on the M13, which tends to lose the initial transients. I don't find either Borg particularly useful for BP or HP duties and this is where the M12 shines. I tried patching both Borgs in a BP series, but didn't find the results as interesting as the dual-peak BP mode of the Cwejman MMF-1. That said, both Borgs are fantastic LPFs with attitude and character. Sonically, the B1 sits squarely between its more aggressive sibling and the rubber-funk of the M12.

You can download the full set of recordings, including the obligatory LPG 'thwap' test, here (3.2MB), but be careful with your speakers on the 'rumble' MP3!

Thanks to Schneidersbuero for the loan of the module.

Richard Scott Live Tonight

If you're in Berlin tonight, be sure to check out Richard Scott's trio at the Sowieso in Neukölln.

Here are the details:

Sowieso Neukölln e.V.
Weisestr. 24
12049 Berlin

Richard Scott (UK) - Buchla Lightning, Analogue Synthesizer
Gustavo Aguilar (US) Drums and Percussion
Olaf Rupp - (GER) Guitar

9 p.m.

Patch Tips #9 - A-119 as Frequency Doubler

The A-119 External Input module can be used to double the frequency of an LFO when used for clocking purposes. Here's the how and why:

Patch a square wave LFO to the A-119's asymmetrical input, set the input gain so that no clipping occurs and then adjust the threshold level to attain a 'clean' signal from the gate out.

Here's an example featuring the original and doubled clock:



Because the A-119 features a full wave rectifier to accomplish its envelope following duties, the negative half, or 'off' period, of the square wave is flipped into positive territory, in effect doubling the frequency.

There is a slight delay to the doubled clock, but this is understandable due to the speed of the A-119 and the threshold necessary to avoid a standing, permanent gate.

In the second example, I've also taken the sine output of the LFO and fed to a wave multiplier to get a third, syncopated clock:



Feeding the wave multiplier with a triangle wave will yield different clocks. For more wave-folded beats, see this post.

Patch Tips #8 - More Feedback

Getting the Plan B M12 SVVF to self-oscillate and 'sine-shaping' à la Bubblesound µLFO. An update to this post and part of my ongoing drive to sell the Doepfer A-133 VC Polarizer.

If you've read that post, you'll know how I go about this so, without further ado, here's the Plan B M15 sine being fed back to varying positive and negative degrees:



And here it is being used as a modulator:



I don't have a µLFO and don't know the Bubblesound circuit, but this certainly seems to yield similar results:



I'd be interested to hear from any µLFO users whether the sine-shaping also causes a change in frequency as per my examples.

Feedback with the Model 12 yields some very interesting results! Depending on the amount of feedback, internal resonance setting and input gain, I got some wonderfully wild sounds. This is the bandpass output being fed-back negatively:



Part of the sound is down to clipping on the input circuit as you can see from these 'scope shots:



Surprisingly, I found that it is possible to FM the M12 at audio rates, although of course not with the precision or clarity you'd get with a non-vactrol-based filter:



The sine output of the M15 was used to FM the M12. The output of the filter was also sent to the sync input of the VCO, resulting is some pleasing, if groggy, harmonic stepping.

4MS Rotating Clock Divider

First impressions of the 4MS Rotating Clock Divider.

This colourful module is an update on the classic clock divider design, offering even and un-even divisions of 1 to 64 and a unique rotate function to shift the resulting triggers along its eight outputs.

Here's a run-through featuring four voices. Towards the end, a random CV is applied to the rotate function.



The next example focusses on the rotate function, which is addressed via a CV. While this is more complicated than stepping with a gate, it allows programmed timing-changes with a sequencer or preset controller like Pressure Points.



The RCD outputs triggers, rather than gates. This is useful for percussive material, but has implications for certain logic gating functions. In this example, the main clock is AND-gated by the /4 output, first with a Doepfer A-160, then with the RCD.



The RCD will also function as an audio sub-divider. Here too, the results are different to the A-160 because of the lack of gates.



Sine wave source mixed with 'divided' signal. Choices joystick used to first rotate and then also change pitch.

The following example uses the RCD as a simple three-voice sequencer. The clock is reset on the first beat of the bar until the 1:25 mark (shortly after the FM index riser). Thereafter, the divisions are allowed to run free until about 1:50 (after the decay of the open high hat is lengthened) when it is snapped back into sync. A joystick was used to provide the rotate CV.



This was a lot of fun, but it did highlight an issue common to both the RCD and A-160: neither play 'on the one'. This is apparent when the drums are faded in (0:30). The cymbal denotes the down-beat, the RCD is playing off-beat. This can be 'corrected' on the A-160 with a logic inverter but, as the RCD outputs triggers, this is not possible. Another thing that became clear was the need for some planning with a programmer to set appropriate divisions, rather than wiggling a joystick!

The RCD got me thinking and working in a way I hadn't previously and I wanted to see whether the A-160/ 1 could compete. In this recording I mimicked the previous patch with the Doepfer clocking modules and fed four different reset triggers via an A-151 sequential switch which I stepped with a manual gate.



This resulted in less drastic changes than rotating divisions, but the shifting rhythmical patterns were no less musical or interesting. I also got the impression that the Doepfer divider had a bit more 'funk' than the 4MS, but this might just be down to timing inaccuracies on the part of the A-160.

The 4MS Rotating Clock Divider is mesmerizing, immediate and a lot of fun. Having easy access to un-even divisions was a revelation and the reset possibilities allow for complex rhythmic patterns. I'm not sure I'd want it as the only clock divider in my system, but it could certainly fulfill that role.

To wrap things up, today's Patch of the Day features the RCD and Plan B's M23 ASR.


shufti

Two VCOs, panned left and right receive shifted pitch and trigger information. A Wogglebug provides a random CV to rotate the RCD, modulate Maths' envelope length and transpose the sequence.