Stacks Image 122

Alpha Pro: Quad Mixer and VCA

Sound Examples

A very quick demo of some of the overdrive sounds available from Alpha Pro.
At its heart, Alpha Pro is four identical VCAs, each with overdrive and stereo outputs. However, it’s also possible to link any of the VCAs together to form a voltage controlled mixer. This flexibility allows Alpha Pro to replace a bank of VCAs, sub-mixers and even your output mixer.

Each VCA has two Signal inputs and a summing mixer with individual attenuators.

There are two mix buses, allowing each VCA to act stand-alone or as part of the mix. So you can configure two separate sub-mixes, with any of the VCAs contributing to the mix, or use all channels to make an 8 input, stereo output main mix.

The VCA gain is controlled by the Initial Gain knob, and two Gain CVs – again mixed together, each with an attenuator. Having two Gain CV inputs allows for more complex modulation possibilities without needing another CV sub-mixer.

Gain response can be set to exponential or linear.

The XING switch enables zero crossing detection to prevent clicks on very fast CV inputs.

Two drive modes are available, a soft clip and a harder fuzz, with the DRIVE control increasing the gain into the overdrive circuit to increase the effect.

The VCA output is stereo, with manual and CV control of pan – again, with an attenuator.

Alpha Pro is available now as a 'founders edition' which includes the Alpha Switch as standard.

Specifications:

Width: 38HP
Depth: 22mm excl. power cable. Approx 32mm inc. shrouded power cable
Power Requirements:
+12v: 250mA
-12v: 100mA
+5v: 0mA
Inputs:
Signal (Zero attenuation): ±5v nominal, ±12v max
Gain CV (Zero attenuation): 0-5v nominal
Pan CV (Zero attenuation): ±5v nominal
Outputs:
Stereo: ±5v nominal, ±10v max
With Drive Modes 1&2 outputs are normalised to around ±5v max

Documentation

Getting Started Guide:
https://www.blaknblu.com/resources/Alpha-Pro-Getting-Started.pdf
User manuals can now be found on the User Manuals page.

Alpha Switch

Stacks Image 340
The Alpha Switch is a 2HP expander to the Alpha Pro VCA.

It breaks out the function links on the back of the Alpha Pro to four switches:

1) Signal Inputs: DC or AC coupled
2) Pan CV: No zero crossing detection, or zero crossing follows XING switch
3) Overdrive Position: With the system set to mono mix, this switch sets whether the overdrive circuit comes pre or post the mix buses
4) Stereo Mix Bus: Controls whether the mix buses are stereo (post pan) or mono (pre pan)

NOTE: Alpha Switch is currently included free in every purchase of an Alpha Pro VCA.

Due to ongoing improvement and development, the appearance and specifications of all products are likely to change.