Novation Bass Station II Self Oscillating Filter Demo

Posted on November 1, 2013 by John CS Keston

I have recently been trying out a Novation Bass Station II monophonic analogue synthesizer. I am quite impressed with this big sounding synth in a small package. While digitally controlled, Novation have focused on packing in proper synthesis features rather than trying to gloss over the sound with onboard effects. For example, as I have illustrated in the video, the filter self oscillates nicely with a clean sine wave that can be modulated in unique ways especially with distinct features like oscillator slew.

The video starts with the self oscillating filter getting modulated by LFO 2 using the triangle wave. After that I switch to using the sample and hold setting creating the well-known 60s computer sound of random notes. Here’s where it gets interesting though. Once I switch the LFO to sample and hold I start turning up the oscillator slew I mentioned earlier. What this does is variably smooth the wave shapes created by the LFO. You’ll hear this come in at 0:28. It sounds like portamento. At 0:35 I switch the LFO to the square wave, but with the slew on it sounds more like a sine. As I reduce the amount of slew the square wave regains its recognizable character. Next I switch it to the saw tooth wave. The nice thing here is that the LFO amount can go into negative values allowing the saw to be reversed.

Another distinctive feature is the oscillator filter mod setting. This modulates the filter with oscillator 2. Since the oscillators range from subsonic to almost supersonic this feature offers modulation effects that are not possible with the LFOs. At 1:29 you will start to hear the oscillator filter mod come in using a pulse waveform. What makes this interesting is that while oscillator 2 is modulating the filter it can also have the pulse width modulated by LFO 1. This can cause bit-reduction-like effects that can be heard between 1:49 and 2:19. At 2:20 I start tapping the octave and waveform buttons on oscillator 2 illustrating what happens when the modulation source is instantly shifted an octave at a time. After a bit more messing around I added a final, manual filter sweep at 3:20.

Pop-up Music: Sangre Azur

Posted on October 23, 2013 by John CS Keston

This the sixth track in a series of mixes that I am creating by improvising on the DSI Tempest synched to the Korg Volca Keys, which is in turn synched to the Korg Monotribe. Minor editing for length and simple processing has been applied, but there’s no extensive post-production or mastering.

I have eleven of these tracks now. In the next entry I will share a link to an album preview on SoundCloud. I didn’t set out to make an album in less than two weeks. However, they kept coming and once I allowed myself to see the tracks as a sort of pop-up music making approach (more about this soon) I allowed myself forgo refining each piece any further.

Pop-Up Northrop: Postfauxpocalypse

Posted on October 21, 2013 by John CS Keston

This is the fifth in a series of mixes that I am creating by improvising on the DSI Tempest synched to the Korg Volca Keys, which is in turn synched to the Korg Monotribe. Minor editing for length and simple processing has been applied, but there’s no extensive post-production or mastering. Produced in preparation for the upcoming event Pop-Up Northrop: Postfauxpocalypse on October 24, 2013.

Pop-up Northrop: Builders of the Universe

Posted on October 17, 2013 by John CS Keston

This is the fourth in a series of mixes that I am creating by improvising on the DSI Tempest synched to the Korg Volca Keys, which is in turn synched to the Korg Monotribe. Minor editing for length and simple processing has been applied, but there’s no extensive post-production or mastering. I have also been producing these tracks in preparations for a performance tonight titled Pop-up Northrop: Builders of the Universe.

Korg Volca Keys Delay Circuit Noise

Posted on October 12, 2013 by John CS Keston

KorgVolcaKeys

I have had the Korg Volca Keys for a little over a week and have gotten quite comfortable with the unit. The feature set can be learned in a matter of minutes, but the sonic range of the instrument is impressive and much more broad than I expected. The strength of the Volca Keys is in the modes: poly, unison, octave, fifth, unison ring, and poly ring. The sound I posted earlier, for example, demonstrates the poly ring modulation mode. Lately I’ve been enjoying syncing the Volca Keys with my DSI Tempest and Korg Monotribe, but more about that later.

Screen Shot 2013-10-12 at 1.02.44 PM

Of course a hardware analog synth that exhibits the diminutive size and cost that the Volca Keys does is bound to have some limitations. From my perspective the most obvious limitation is the quality of the onboard delay. According to Korg’s block diagram the delay is the final circuit in the signal flow. Therefore, high frequency noise coming from the delay can’t be rolled off with the filter. The noise is most obvious when playing a sound that is programmed with the cutoff frequency most of the way down, the delay time at the slowest setting, and the feedback at the highest setting.

To illustrate the noise introduced by the delay circuit I created a few versions of a simple test sequence. One without delay, one with the internal delay, one with Ableton’s Simple Delay, and finally one with my Electro-harmonix Memory Man Delay. The sequence sounds pretty clean on its own, but buzzy, high frequency aliasing becomes audible when the Volca’s delay is introduced. In comparison, Ableton’s Simple Delay doesn’t add any noticeable noise, while the Memory Man adds a little noise (and pleasant chorusing), but nowhere near as much as the Volca delay.

Korg Volca Keys Sequence with No Delay:

Korg Volca Keys Sequence with the Internal Delay:

Korg Volca Keys Sequence with Simple Delay:

Korg Volca Keys Sequence with Memory Man Delay:

Some might find the buzzy delay noise desirable at times. To me it sounds more-or-less like a cheap, digital delay circuit that uses some down sampling and/or bit reduction to handle the memory requirements for the repetitions. I have also noticed that the filtering on the delay trails is significant. Cranking up the cutoff and lowering the attack, decay, and sustain on the EG produces obviously muffled delay trails. All of these limitations are not that noticeable when you’re using the Volca alongside two or more other instruments, but I plan on using my Memory Man as an alternative to the on board delay when it’s convenient to do so.