Studer A-820-24
Twenty-four tracks of analog tape, aligned by microprocessor and built to a standard that studios bet their session budgets on.
Overview
The A-820-24 is a 24-track analog multitrack recorder. Studer's own advertising said it "stands unchallenged among multitrack recording systems for easy, practical setup and studio use." That's marketing copy, not a verdict, but the feature list behind the claim is real, and it's what separates this deck from the analog multitracks that came before it.
The headline feature is fully microprocessor-automated audio alignment. According to Recording-Engineer (April 1988, p.86), the A820-24 can automate both record and reproduce alignment with minimal human intervention. That's a step beyond machines like the Otari MTR-20, which automated record alignment but left playback alignment to the engineer. The same piece notes that the automated function can be bypassed for manual adjustment, which suited the engineers who never fully trusted a machine to do their overbias work. The alignment order follows the logic a human would use: high-frequency equalization affects overall gain, so the machine sequences its adjustments to minimize repeat passes.
Trimmer information is displayed on the overhead meter panel, and here Studer made a choice that still divides people. The company showed trimmer values in hexadecimal rather than decimal, so two digits can represent numbers larger than 99. Recording-Engineer (April 1988, p.86) flagged the decision directly, noting that the more compact hex format is what Studer went with. The same system stores default or user-selected digital trimmer values in non-volatile memory. That lets an entire setup be recalled at the next session, or swapped when the studio changes tape formulations between brands. Trimmer values can also be downloaded through the machine's RS-232C port to a computer, or as an FSK audio signal stored on an open track of the session tape itself.
Studer's advertising described the transport as a "compensating lever" design, developed through independent primary research, that delivers uniform tape-to-head contact across all tracks. The pitch was that it virtually eliminates uneven head wear and keeps level stability high on the outer tracks, where it's hardest to hold. The record and reproduce heads are amorphous metal. The deck is prewired for Dolby A/SR cards, and switchable Dolby SR and Dolby A noise reduction on a single plug-in card was introduced as an option after launch. Studer also engineered the audio electronics to exploit the extended dynamic range of then-new high-flux tapes like Ampex Grand Master 499 and 3M 996, with or without noise reduction engaged.
Studer's advertising for the A820 line also lists semi-automatic audio playback alignment, automatic Dolby alignment, extremely fast yet gentle start-ups, and digitally controlled audio electronics among the standard features. The company's pitch about build quality is that from the record and playback heads down to the machine screws, the A820-24 is entirely Studer-engineered and manufactured to Studer specifications. The company traced that continuity back four decades through the A80 and A800.
Studer's own advertising also leaned hard on the factory-installed sales engineer who comes onsite to install the machine. This was not a piece of gear you unboxed and plugged in. It was capital equipment sold into professional rooms with a service relationship attached.
In the Studio
The A820-24 shows up in the trade-press studio listings of the late '80s and early '90s as infrastructure, not as a talking point. Mix-Magazine (October 1989, p.30) described a Columbus facility running two A-820 24-tracks loaded with Dolby SR alongside a 60-input Neve V series. Mix-Magazine (February 1989, p.141) ran a Muscle Shoals Sound advertisement name-checking the A-820-24 with Dolby SR.
The automation doesn't remove the human. As Recording-Engineer (April 1988, p.86) put it in its survey of auto-alignment systems, you still need to bring your skills with you to work. Mechanical alignments like head and tape path alignment have to be done properly before the automation is worth anything, and the input level alignment, internal oscillator, and VU meter calibration all still fall to the operator. Once those baselines are set, the machine can lay down session tones according to a preprogrammed setup and recall trimmer comments the operator entered to identify setups. That's useful for comparing before-and-after adjustment values, and a rough gauge for head wear.
Studer also introduced software for enhanced operation of the A820-24 in the TV and video post environment. With programmable transport and RS-232 control ports, a 24-track analog machine could keep working in post as music tracking migrated to digital, chasing timecode and handling the repeatable setup work that post houses needed.
Collectibility
Twenty-four-track analog tape machines are not casual purchases. A Mix-Magazine (June 1995, p.218) classified listing offered a Studer A820 24-track with Dolby SR, full remote, and low hours at $67,000, which shows what these commanded in the mid-'90s, when they were already secondhand. The same listing priced a Studer A820 2-track half-inch at $13,500.
That $67k figure is the whole story of owning one. It's not a machine you buy on a whim; it's a machine you buy because you have the room, the tape budget, and a reason. The good news is that Studer built these to survive professional use, and the alignment automation that made them expensive new is what makes them tractable to keep running decades later — the machine remembers setups that would otherwise live in a notebook nobody can find. The bad news is everything else about maintaining a 24-track: head wear, tape path alignment, and a parts and service ecosystem that has thinned out considerably since the Studer Revox America offices in Nashville were taking these calls.
Anyone chasing one should check head condition and whether the Dolby cards are present. The deck is prewired for them, but the noise reduction itself was optional and often bought separately. A machine with the SR/A cards installed and a documented service history is a different proposition from a bare transport that's been sitting in a storage room. The hex-format trimmer display that Recording-Engineer flagged in 1988 can make a first session feel like a puzzle if you aren't expecting it.