Studer D740 (1991–1992)
A self-contained CD recorder that replaced a rack of outboard boxes with one die-cast aluminum chassis. It cost about as much as a decent car.
Overview
The D740 made CD recording feel like using a cassette deck. First-generation recorders were typically assembled from off-the-shelf hardware, spread across at least two chassis, and often needed a personal computer running finicky software to drive the encoder and subcode generator. Studer developed the D740 jointly with Philips and launched it at the Paris AES convention. It packed the complete read/write unit, converters, encoder, decoder and subcode generator into a single die-cast aluminum chassis the size of a home stereo receiver. No PC, no external filters, no second box. Mix (June 1991, p.7) walked through the design and noted the recorder needs no computer interfacing at all.
The recorder adheres to the Orange Book standard for CD-R, so discs written on it play back on any standard CD player once finalized. That mattered in an era when "CD master" usually meant a U-matic or DAT intermediate. An incomplete disc can be stopped and restarted, and the recorder keeps the nonstandard contents data internally. Because the disc lacks the final Red Book table of contents, it will only play on the D740 itself. Pressing the "keep" button writes the completed TOC to the disc lead-in, and the disc becomes universal. Unwanted passages, like dead air during a live performance or a bad take, can be marked before finalizing so the recorder skips them on playback, even though the data physically remains on the disc. The TOC can be built manually with a New Track button or generated automatically by an auto mode that hunts for level drops greater than 60 dB. Copying a CD-R carries the track information across automatically. Studio Sound (May 1991, p.?) covered the launch and confirmed both the manual and auto TOC modes along with the temporary-TOC feature for work to be continued.
Around the back, the D740 carries balanced XLR line inputs and outputs, fixed unbalanced RCA outputs, digital inputs via optical, RCA and XLR (S/PDIF and AES/EBU), digital outputs on the same three connector types, and a 25-pin parallel remote socket with fader start. There's also a calibration facility for fixed studio levels and automatic clock changeover to the digital input, so the machine can lock to an incoming signal rather than free-run. Sampling frequency is fixed at 44.1 kHz.
Frequency response deviation is no more than ±0.2 dB, THD+N stays under 0.008%, channel separation exceeds 80 dB, and phase linearity is under 3%. Philips-made one-bit bitstream converters run in differential mode. Maximum input level at 10k ohms is +24 dBm and maximum output level at 600 ohms is +24 dBm. The unit measures 19 inches wide, 5.25 inches (three rack spaces) high and 13.5 inches deep.
Mix (June 1991, p.7) figured list would land under $20,000, and the EQ magazine buyer's guide pegged it at $12,950. That is a lot of money even for a broadcast facility. It was aimed at radio broadcasters for jingles and sound effects, and at studios cutting reference discs, demos, promos and CD masters. For archiving, the D740 offered the highest quality digital audio on a virtually nondestructive medium that takes up very little inventory space. Typical CD-R discs used a gold reflection layer with roughly 70% reflection ratio, an organic dye recording layer and a polycarbonate substrate, with a maximum recording time of 74 minutes (about 650 MB) and a projected lifetime greater than ten years. Keep them out of direct sunlight.
It's worth knowing the D740 had a short run at the top. Its successor, the D741, arrived with analog I/O, AES/EBU and S/PDIF, a standard SCSI-2 interface, and a built-in sample-rate converter accepting 32–48 kHz on the digital inputs — a meaningful step up for facilities dealing with mixed-rate sources. Collectors chasing a D740 today are chasing a specific moment: the point where CD recording became a single-box, studio-grade proposition. The die-cast chassis and the ±0.2 dB flatness are the reasons to care; the Orange Book workflow and the $12,950 original price are the reasons to know what you're getting into.
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.