Ashly SG-33
A two-channel noise gate that took a studio cleanup tool and gave players something they could shape sound with.
Overview
The SG-33 is the two-channel member of Ashly's SG-Series of noise gates. In its own advertising, Ashly argued that gates had started as a way to scrub unwanted background noise, then became a creative tool for shaping a mix - and that something more flexible was needed to bridge the two. The SG-Series was the answer, and the SG-33 (alongside a four-channel sibling, the SG-35) was how it reached the rack. Ashly had been at it since 1972, and the ad copy carried the Rochester, New York company's address and toll-free number.
The timing controls are what separate this gate from a bare-bones one. Ashly's own literature for the SG-Series lists an attack variable from .01 to 150 mSec, a hold that runs from .04 to 12 Sec after attack and before fade, and a fade from .015 to 30 Sec. The threshold spans -40 to +20 dB. The floor, which is the level the signal drops to while muted, is adjustable from -75 to -1.5 dB. These aren't token trims. A 150-millisecond attack and a 30-second fade let an engineer do things a gate with fixed fast attack and short release can't, and the wide floor range means the muted state can be a hard chop or a gentle duck, depending on the track.
DB Magazine (January 1986, p.68) described the SG-33 as a versatile two-channel noise reduction system occupying a single rack space, designed to control leakage and background noise in recording and sound reinforcement, and acting like a level-sensitive switch that attenuates signals falling below a user-selected threshold. The same writeup noted the extremely fast attack time and a 60 dB threshold range — consistent with the -40 to +20 dB figure Ashly published — and mentioned per-channel in/out bypass switching.
The key input on each channel is what pushes the SG-33 past simple gating. It lets the VCA be triggered by a signal other than the one being gated. Split and modify the source, run it through external EQ say, and the original can feed both the gate and the key inputs for fine-tuning and special effects. There's also a tie patch point that permits linking two or more gates together for synchronous tracking or master/slave setups. So instead of reacting only to its own channel, the gate can be driven by a hi-hat track, a vocal, or anything else you want as the trigger.
Ashly built the SG-33 around a proprietary VCA, which the company claimed exhibits low distortion and low control-voltage feedthrough - the turn-on click that plagues cheaper gates. A dual-release-time circuit offers a "wait-before-fading" option, which is the hold control doing its job. DB Magazine (November 1989, p.72) listed the SG-33 as a single-rack-space unit weighing 8 lbs, with the four-channel SG-35 taking a double rack space at 10 lbs. Price was listed as available upon request in that directory, so the original sticker isn't firmly recorded here.
The SG-33 turns up in working rigs, too. A studio profile in EQ magazine's "Studio Recording on Tour" feature listed Ashly SG33 stereo gates among the outboard gear in a Boston-based mobile setup, alongside an Ashly SC-66 parametric EQ.
The SG-33 is a single-rack-space, 8-pound, two-channel gate with a proprietary VCA and a control set - key inputs, tie points, wide attack/hold/fade/floor ranges - that makes it useful for far more than noise cleanup. The four-channel SG-35 covers the same ground in a double-space box. Documentation is thin on exact production years and original pricing.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.