EMT 140-ST
The steel plate that was already the world standard before anyone thought to call it vintage, and the variant nobody bothered to document.
Overview
The EMT 140-ST is a stereo reverberation plate. It's a steel sheet hung in a frame, driven by a transducer, picked up on the other side, and made to ring for a second or four at a time. It is, by every indication, an EMT 140 with a "st" appended, and the "st" almost certainly means stereo. What else it might mean, the surviving paperwork won't say. Owners and collectors chasing a definitive 140-ST datasheet will come up empty. The model shows up in period equipment inventories and auction descriptions, not in catalog copy.
The record does establish that the 140-ST was not a curiosity. A 1970 issue of Broadcast Engineering (May 1970) described the EMT-140st as still the world standard in the recording and broadcasting industries. That's a big claim for a device built around a piece of sheet steel, and it was made years after the design had already been in service. By 2004, a Gearspace thread could note the plate was used in most major studios worldwide, and nobody argued the point.
The naming is a mess. Sources render the model as "EMT 140ST," "EMT 140st Stereo Reverb Plate," "EMT 140 ST," "EMT-140st Reverberation Unit," and "EMT 140 st," sometimes within the same document. The EMT manual text itself mixes "EMT 140 TS," "EMT 140 FB-TS," "EMT 140 FB," "EMT 140 FBst," and "EMT 140 st" across different passages. Treat any single spelling as a convenience, not a specification.
Key Features
The Renowned Steel Plate
The heart of the unit is a steel plate, and Broadcast Engineering (May 1970) referred to it simply as "its renowned steel plate," with no further elaboration needed for the readership. The plate gives the EMT a dense, fast-building decay that behaves nothing like a room, because it isn't one. The archive's own manual excerpts for the 140 family describe a porous panel suspended parallel to the plate and swung toward or away from it to vary decay time. Whether the 140-ST uses that exact mechanism is not documented for this variant specifically, but the family architecture is consistent across the naming variants.
Tube Electronics
At least some 140-ST units are tube-based. An owner of a 140 ST describes it as a "fully tube plate reverb," and a related Neumann EMT V54/S tube preamp is documented as having originally served as a playback amplifier, with special equalization, for a studio echo/reverberation system of type EMT 140ST. Tube electronics are the variant most often cited in repair complaints. Capacitors and tubes age, and the high-gain amplifier that drives the plate is unforgiving of drift. Confirm which electronics a given unit carries before assuming tube or solid-state.
Stereo and Mono Operation
The EMT 140 manual text states that the reverberation units are suitable for reverberating stereo and mono recordings, with mono recordings using only one channel. The same text notes that depending on the stereo recording process used, the unit may be connected in several ways. So the 140-ST is not a fixed-configuration box. It expects the engineer to think about how the returns are patched.
Remote Control and Voltage Variants
An internal remote control outfit, designated EMT-140 F, is referenced in the family documentation, and at least one 140-ST has been sold with a remote control included. For units operated from AC voltages other than 220 V, an additional transformer designated S 140-232 W is required. The wider 140 family was supplied for 110 V, 117 V, or 240 V with a factory-set transformer designated S 140-B. Anyone importing a plate should verify which voltage configuration the unit left the factory with. A mismatch here is not a small problem.
Historical Context
The 140-ST sits inside a family that dominated studio reverb for decades. dB Magazine (July 1992, p.55) noted that recording and film studios purchased thousands of EMT 140 units over the years, and that even when digital reverbs gained popularity in the early 1980s, they never achieved an exact simulation of the EMT 140's sound. The same source put the standard 140 at roughly 7.5 × 4 × 1.5 ft and in excess of 400 lbs. Treat those figures as family-level context, not confirmed 140-ST specifications.
The manual text names several siblings - EMT 140 TS, EMT 140 FB-TS, EMT 140 FB, EMT 140 FBst - but no source states the hierarchy between them and the 140-ST. What can be said is that the 140-ST was in professional use by 1970 and still turning up in facility inventories decades later. A 1987 studio equipment list in Studio Sound (March 1987, p.76) records EMT 140 stereo echo plates among a working facility's gear.
Collectibility & Value
No complete-unit sale prices for the 140-ST turn up in the available documentation. That's odd for a piece this well known, and it probably reflects plates changing hands privately or in studio liquidations rather than on open marketplaces. The only price figure in the record is a $50 stereo pickup kit offered as a reduced-price accessory in a 2004 Gearspace thread. That says something about parts availability, not about valuation.
The failure modes, on the other hand, are well attested. Owners report noisy amplifiers and a high-pitched ringing sound. One owner describes a unit converted to solid-state years earlier that had grown progressively noisier until it became unusable, and was seeking a technician in the New York area. Another reports being unable to find a service manual anywhere. Service documentation does exist - a service manual for the EMT 140 Reverberation Plate and a 140 ST schematic are both referenced - but locating them is clearly part of the ownership experience. Tension clips and pickup kits have been available as replacement parts. A plate with a failed pickup is a very large paperweight.
Positive reports exist too. A 2004 auction description called a 140-ST "fabulous," in good condition, sounding excellent, and including its remote control. Condition, completeness, and electronics type drive everything, and there is no published price guide to lean on. Anyone shopping should budget for a technician, verify the voltage configuration, and confirm whether the electronics are tube or solid-state, because the unit weighs more than most people can move alone.
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