Audioscape MAP D.AM-27 Dual Channel Mic Preamp - Used  From Audioscape

MAP: Powered by AudioScape

AudioScape is proud to announce the modern relaunch of Modular Audio Products, otherwise known as MAP. In the early 70’s, MAP was descended from an earlier electronics manufacturer called Melcor® Industries. Melcor® pioneered the use of discrete class A op amps in audio. Their renowned 1731® class A discrete op amp preceded another Farmingdale, Long Island audio-maker’s well-known discrete op amp. When Melcor® abandoned the audio business for calculators around 1970, a group of their engineers carried on as Modular Audio Products, with the 1731® op amp at the heart of a range of products. Of course, these early discrete op amp beauties are highly sought after today. Now, AudioScape will begin manufacturing MAP products again, bringing that classic mid-century vibe to the new millennium.

A Discrete Audio Classic Reborn - Like NOS!

Our inaugural MAP release, the D.AM-27 class A dual mic preamp, is based on Melcor’s® AM-27 preamp. Each channel features our proprietary, in-house manufactured, MAP 1731® class A discrete op amp, as used in the original AM-27. These were the first op amps used in audio processing gear, by Melcor® Industries, in the late 1960’s. Each of today’s MAP 1731® op amps features the same carbon composition resistors and transistors as originally used. The D.AM-27 is like having a NOS AM-27 built 50 years ago . It has that unmistakable harmonic sheen and midrange richness. 

Modern Workflow Essentials

To make this retro classic user-friendly in the modern workflow, some essential additions to the D.AM-27 were made. These include phase invert, 48+ phantom power, switchable high (120 Hz) and low (15 kHz) pass filters and a -20 dB pad on each channel. In addition to mic-level inputs, each channel also has a +4 dBm line-level input, so it can be used for added color across the stereo bus or an existing track. There’s a DI input as well. Input gain and output level fader controls, with a handy VU meter that meters input gain levels, complete the modern additions.

The 1731 Class A Discrete Op Amp - The OG Op Amp

The MAP 1731® op amp utilizes all thru-hole old-school components; this is like a vintage op amp coming off the production line in 2024. It is based on the 1731 op amp that originated with Melcor® in the late 1960’s, though MAP utilized this op amp design (and others) in its projects after Melcor’s® demise. We are including some photos of MAP’s 1731® above for historical reference. Having dissected many of these over the years, we found that the earliest versions of the 1731® were constructed with carbon composition resistors and film caps, later versions moved to carbon film resistors. We have opted to use carbon composition resistors in this run (yum!) and styroflex caps across the input. The same, original, 2n3707 transistors are utilized throughout. One modern deviation, for reliability and tone, is the integration of silver-can output transistors. These vintage style transistors can handle the heat dissipation better and, quite frankly, we found them sonically superior in our listening tests. With this minor but necessary change, these op amps are now made to last a lifetime.

Why Modular Audio Products?

The idea of bringing this back is to pay homage in the most respectful way possible to Modular Audio Products, while tapping into the spirit of what they set out to achieve. The original MAP products, while rare, were highly ambitious designs for their time and would still be on the must-have list for many studios. Chris has been personally collecting and admiring these original pieces for many years.