500 series « Bigknob Audio

Retro Doublewide

The Retro Doublewide is a true variable-mu tube compressor module designed from the ground up for the 500 series. It’s authentic Retro compression for the masses. The Doublewide delivers the tube compression sound you...(more)

Forssell Technologies SMP-500series

A version of our well-known SMP-2 microphone preamplifier, the Forssell SMP-500 has been adapted to work with the API 500 series enclosures. This extremely high-quality, sonically neutral microphone preamplifier is designed for the...(more)

Tonic

The tonic offers 3 bands of equalisation with a versatile sweep midrange section and fixed two frequency high and low bands. The tonic also has a high pass filter utilizing another real choke. The...(more)

Potion

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...(more)

Essence

The essence is a True Class A Optical Compressor designed to fit the API* 500 VPR Series rack frames offering a great feature set in a compact package. The essence will find application with...(more)

Elixir

The elixir preamplifier module is an excellent compliment to the “fatter” sound of many modules now available in the API* 500VPR Series format and has been designed to provide exceptionally low noise wide bandwidth...(more)

API 560

Originally conceived for use in API consoles of the ’60s and ’70s, the 560 is a unique device designed to accomplish tasks that no other EQ can. Extremely fast to set and reset using...(more)

API 550B

The benefits of the API 550b are most obvious to those who work with EQ on a continuous basis. If major tonal restructuring is required, the extraordinary headroom made possible with API’s 2520 Op...(more)

API 550A (SW)

This limited edition EQ is a continuation of the equalizers produced by API exactly as they were in the 1960′s, featuring hand-wired switches, the original circuit board design and API founder Saul Walker’s signature...(more)

API 550A

The 550A provides reciprocal equalization at 21 points in 7 steps of boost to a maximum of 12dB of gain at each point. The fifteen equalization points are divided into three overlapping ranges. The...(more)

500 series