Tag Archives: VCA

Xelex XM-201

Xelex XM-201 Voltage Controlled Amplifier

I’ve acquired three “Xelex XM-201” NOS.
Can’t wait to build something kool with these.

Here is the Xelex XM-201 datasheet:

  • Xelex xm-201 Datasheet Page 1
  • Xelex xm-201 Datasheet Page 2
  • Xelex xm-201 Datasheet Page 3
  • Xelex xm-201 Datasheet Page 4
  • Xelex xm-201 Datasheet Page 5

Xelex: Wikipedia

Ninjani Diskus
Ninjani Diskus

Quad VCA with Attenuator

VCA 424

Quad VCA with Attenuator
Quad VCA with Attenuator

Voltage Controlled Amplifier

VCA 424 provide voltage-controlled amplification.
The amount of amplification the VCAs provide is determined by the voltage at the CV input, and the position of the gain control, which sets the overall gain in the system.
The VCA has 4 audio inputs, each with an attenuator. They are amplified by an amount determined by the combination of the gain and the 4 CV controls. OTA based.

Part of the Synthesizer Modular

Minimaeen 424

Minimaeen MM-424

Minimaeen 424

Minimaeen is a little analogue bass/effect synth, with very kool sound tweaking abilities.

Built around 2 Philips NE5517. Its oscillator has selectable square and triangle wave output. Diode ladder filter with it’s screaming cutoff and resonance, makes tweaking a joy.

Minimaeen has a low frequency oscillator that can be routed to the voltage controlled oscillator or the filter cutoff.

The envelope can be trigged by pulse or a push-button on the panel controlling the voltage controlled amplifier or/and cutoff frequency. Continue reading Minimaeen 424

Ninjani Bassline

Video of first test of ”Ninjani Bassline” back in 2008.

Why I posted this now is because I just dug it up again and dusted it off, then decided to finally finish building it. So you can expect new pictures and maybe a new video of the finished synth soon.

What needs to be done is merely cosmetic, knobs , panel layout and minor final fine tuning adjustments.

“Ninjani Bassline” is a essential sequential analog synthesizer I built in 2008. It has a VCO, 2 AR Envelopes, VCF, VCA and a 16 step sequencer.

1 x VCO -Voltage controlled oscillator – OTA. Square and sawtooth wave.
1 x VCF – Voltage controlled filter – Sallen Key, Korg MS-20 type clone. Low-pass & High-pass.
2 x EG – Envelope generator – Basic envelope attack and release.
1 x VCA – Voltage controlled Amplifier – OTA Based.
1x Sequencer – “16 steps VCO pitch” or “8 steps VCO pitch and VCF cutoff”