Warm Audio WA-1B Tube Optical Compressor (Demo, minor marks) is a used item in excellent condition, listed on Reverb. The asking price is £1,059. It is offered by Blackout Audio through Reverb. Local pickup is available. It is in our Preamps & Channel Strips category. 24 similar listings have a median asking price of £670. Used Gear Hunter first saw this listing on 1 October 2026 and last saw it on 2 November 2026. It has been seen 16 times in our scans. Prices are converted from the seller's currency when we scan the listing, so the amount you pay may differ slightly. The seller sets shipping, and import duty or VAT may apply, so check the final cost and the item's details on Reverb before buying.
From the seller
Store demo unit with minor cosmetic marks.
The Warm Audio WA-1B is a single-channel, all-tube optical compressor that recreates the Tube-Tech CL 1B, a Scandinavian design prized for its smooth, musical compression on vocals, bass, and dynamic sources. Hand-wired with a true-to-spec 270V discrete analog signal path, the WA-1B pairs Lundahl Sweden transformers with Tung-Sol and JJ tubes to deliver tube-optical warmth with the precise attack, release, ratio, and threshold controls absent from simpler vintage optical designs.
Precision Controls
Unlike simpler optical compressors with only gain and peak reduction knobs, the WA-1B provides full dynamics control:
Variable threshold, ratio (2:1 to 10:1), attack, and release
Three compression modes: Fixed (natural optical timing), Manual (user-set attack/release), and Fixed/Manual (blended)
Dedicated sidechain bus selector (Off, Bus 1, Bus 2) allows interconnecting and linking up to 10 WA-1B units
Front-panel bypass switch and VU meter (switchable input, output, or compression)
Tube Circuit
The WA-1B operates at a true 270V rail voltage, replicating the headroom and dynamic behavior of the original Scandinavian design. A Tung-Sol 12AX7 handles the gain stage while a JJ 12AU7 drives the optical detector and output. Custom large-core Lundahl Sweden transformers on both input and output contribute the smooth, open character associated with Nordic transformer designs. The linear toroidal power supply provides clean, stable current to the tube stages for consistent performance.
Specifications
Type: Single-channel tube optical compressor
Topology: 270V, Class A, all-discrete, hand-wired
Tubes: 12AX7 (Tung-Sol), JJ 12AU7
Transformers: Lundahl Sweden (input and output, custom large-core)
Ratio: 2:1 to 10:1
Threshold: Off to -40 dBU
Output gain: Off to +30 dBU
Frequency response: 5 Hz - 25 kHz (-3 dB)
Self-noise: <-75 dBU at 30 dB gain
CMRR: >60 dB at 10 kHz
Input impedance: 600 Ohms
Inputs: 1x XLR, 1x 1/4" TRS (balanced)
Outputs: 1x XLR, 1x 1/4" TRS (balanced)
Sidechain: 2x 1/4" bus connectors
Metering: VU (input, output, or compression)
Power: Linear supply with toroidal transformer, IEC
Rack size: 2U, 19"
Dimensions: 483 x 184 x 89 mm (19 x 7.25 x 3.5")
Weight: 3.9 kg (8.6 lbs)
In the Box
Warm Audio WA-1B
IEC power cable
