The potion is a True Class A FET based Compressor designed to fit the API* 500 VPR Series rack frames. The potion will suit those looking for a audio compressor with "attitude" and is particularly useful in rock, hip hop and modern music styles where a somewhat aggressive character adds to the energy of the track. Drums, electric guitars, vocals and the mix bus will all benefit from the potion's rich harmonic sound - potion - the harmonic energizer!

Although the potion uses a FET (Field Effect Transistor) as the gain reduction element (like a well known classic limiter), the control circuitry (or side chain) is a completely new Buzz Audio design with some real innovative techniques to achieve an original compression characteristic.

Included in this new circuit is an element we have nick named "Ready To Rock" (RTR). This circuit automatically alters the Release time setting of the compressor depending on the attack depth and prevents the compressor from over shooting and undesirable "pumping" when using faster Attack settings. A front panel LED indicates when this is function is active. (Actually, RTR stands for Release Time Reduction, but call it what you will!).

As you can see from the specifications, the FET itself produces a relatively large amount of harmonic distortion compared to Optical and VCA compressors, but this distortion is the sound that will add energy and richness to your tracks.

The potion is capable of of very fast attack (less than 50uS at F attack setting) and when set to 20:1 Ratio, we believe it approaches the performance of "look ahead" digital limiters within the constraints of the analogue domain.

Click here to hear the potion in action on a snare drum track demonstrating the quick and controlled attack time.

The audio section of the potion consists of our unique True Class A BE40 and BE50 amplifiers coupled with Lundahl input and output transformers for a fast yet full sonic signature. The input signal is passively coupled directly to the FET element via the input transformer, amplified and balanced via the ouput transformer - a simple signal chain.

In addition to the Gain, Drive, Attack and Release controls, we have included a % Mix control which allows the user to mix the uncompressed (input) signal with the compressed (output) signal providing yet another means of obtaining an original sound on your tracks.

The potion consumes 2 slots within the 500 Series frame. The audio in/out connectors of the first slot carry the main signal path whilst the in/out connectors of the second slot are utilized as a side chain insert point where external equalization can be applied to alter the compressor sensitivity at different frequencies. This insert can also be used for compressor "keying". A switch on the front panel allows the user to monitor the side chain insert and switch it in and out of circuit. Two potions' can be linked for stereo (mix bus) operation.

Rack Compatibility
The potion power consumption of 120mA is higher than other 500 series modules, but because this demand is spread over two slots (60mA each) it should work fine in all available racks. For more information on linking two potion units, please read this.

• API* 500VPR Series rack module format - plug in and play!
• Advanced analogue technology - not a clone or copy of products from the past.
  
• Powerful fully discrete hi-bias, wide bandwidth, differential Class A amplifiers.
• Passive transformer coupled input, transformer coupled output
• Side chain insert point with monitor.
• FET gain reduction element for harmonic character.
• VERY fast attack.
• Unique RTR Release Time Reduction circuit.
• May be linked to another potion for stereo operation, more info
• Switchable 10 segment VU meter