SPL Iron Mastering Compressor (All Black)

SPL Iron Mastering Compressor (All Black)

Styled in all black, the SPL IRON Compressor is a two-channel, variable-bias compressor and limiter intended for use in the mastering process. It is inspired by the classic designs found in Fairchild and Gates compressors, which utilize remote cut-off tube biasing to achieve a musical type of dynamic restriction. However, the IRON updates this design for a new modern era with several interesting features.

First, the compressor offers an ancillary sharp cut-off tube path in parallel this topology can lead to much more transparent compression. Also, an independent feed-forward resitive opto-isolator has been placed in the control path of the tube circuit. This limits peaking, and allows for a small amount of THD when compared to other compressors of a similar ilk. The sonic byproduct of this desgin is a smoothier, silkier sound.

You ll also note a complex rectifier circuit, which changes the attack and release times, curves, and all around behaviors this rectifier circuit makes the compressor truly versatile, and able to accommodate all sorts of program material. The compressor offers tube biasing, for more minute control.

For connections, SPL supplies the IRON with balanced XLR terminations on the inputs and outputs, and 1/4 jacks on the sidechain inputs. You ll also find a built-in sidechain EQ for filtering the sidechain signal, ensuring no stray kick drum accidentally triggers the compressor. However, note that this sidechain filter goes beyond the usual HPF found on many a compressor complex filtering shapes are provided, so you can better tune the compressor s behavior to respond to individual elements within a mix, such as vocals or guitars. A power cord is included.

Variable-bias tube compressor

Parallel dual-tube circuit

Mu-Metal iron transformers

Peak signals of the control voltage are limited by a feed-forward resistive vactrol-opto-isolator

Compression behavior of the tubes can be adapted to program material with tube bias (with three different settings), A±12 dB input gain, and threshold control

Six different rectifier settings available with different diodes (germanium, silicon, LED, mixed)

Sidechain EQ allows you to choose between off, four sidechain-filter presets, or an external sidechain signal

All functions can be adjusted via switches or, in the case of the Threshold, with a detented potentiometer

In Link mode, the threshold, tube bias, attack, release, and rectifier parameters, as well as the sidechain EQs, are controlled with the right side (channel 2) of the unit

Additional passive 120V equalizer with two presets (AirBass and Tape Roll-Off)

Interval control in Auto Bypass mode helps compare the original and compressed signals

High dynamic 120V operating voltage

Suitable for subgroups and mastering studios

Designed, developed, and manufactured in Germany