Vac Rac TSL is Kazrog's official emulation of the Inward Connections Vac Rac, a tube optical compressor/limiter hand-built today by Steve Firlotte, who worked with Kazrog on the plugin. It models four units: the TSL-5 and TSL-4 from Devin Powers' collection, the TSL-3 from Ross Hogarth's own unit, and the transformerless TLM-1 signal path from JJ Blair's original Vac Rac, which you blend in on top of the chosen voicing. It costs $49.99 at launch in Kazrog's store, down from $79.99.
Its strength is control. Classic opto plugins give you gain and peak reduction and little else. Vac Rac TSL gives each of its two channels a detector high-pass filter, ratio from 2:1 to 12:1, up to 40 dB of reduction and makeup gain, then adds a THD control that drives the tube stages from warmth to heavy distortion. Dual-mono, stereo-link and mid/side modes, sidechain filters and a wet/dry mix make it useful on buses as well as single sources, and Kazrog's Analog Entropy gives the two channels slightly different, hardware-like behaviour.
The trade-offs are the usual ones for an opto design: the release is smooth and the attack is not fast, so it will not catch sharp transients the way a FET or VCA compressor does. Windows users get VST and AAX only. And it is sold only in Kazrog's own store.
Against its alternatives, the UAD LA-2A Collection is the authentic Teletronix sound and is $39 at Plugin Boutique until 31 October, and Waves CLA-2A is $34.99 until 1 November. Both are simpler. Choose Vac Rac TSL if you want tube opto colour with real ratio, drive and M/S control. Our first look at Vac Rac TSL covers every feature.