McGary Audio

Monday, December 21, 2009

Home Recording Extra!
API A2D Stereo Microphone Preamp,
Analog-to-Digital Converter

Professional Build, Audiophile-Caliber Sonics!

by John Gatski
If you are in the market for a professional, high-quality stereo microphone preamp for your home studio or remote recording rig, the API A2D offers a quality microphone preamp with audiophile-caliber specs — plus an excellent A/D converter that operates up to the 192 kHz sampling rate. API has the reputation as one of the premiere professional analog manufacturers (consoles, preamps, compressors, etc.), and it is fitting that they combined stellar analog with a little bit of digital.

The details
Priced at $2,199, the made-in-USA A2D features a separate analog preamp section with each channel controlled by its own gain potentiometer. and input level is indicated by separate Channel 1 and 2 peak meters (L and R). The preamp features front panel controls: 48V phantom power, phase switch, line/mic selector and a gain pad for extra compatibility with line sources. Preamp Ins and Outs are via rear panel balanced XLR jacks, as well as a pair of front-panel 1/4-TRS jacks. A rear-panel set of 1/4 inch TRS input jacks allows a straight connection to the A/D converter for fixed line sources or processor returns. (these jacks are perfect for analog dubs of high-res music from audiophile SACD or DVD-A players).
The A/D has user selectable sample rate adjustment from 32 kHz to 192 khz. Word length is always 24-bit. Thanks to the THAT Corp.‘s electronics used inside the A2D, the analog and digital specs of the API are excellent with rated noise EIN at -129 dB (mic) and -125 dB (line). At 48 kHz, 96 kHz and 192 kHz, A-weighted dynamic range is rated at -120 dB. The THD + noise is -110 dB. Great specs indeed!
Digital output options include RCA SPDIF and AES/EBU via XLR. Both jacks output stereo 192 kHz digital. For professional use. The API also has digital connection for synchronizing to an external clock and d-sub connector to allow connection/synchronization of multiple A2Ds.

The audition
I used the A2D for my microphone roundup (posted on Dec. 15) recording sessions. With all the microphones, it without any problems. And even though there were two separate sections to set up, it was quite easy. I used the preamp gain knobs to set the input level, most of time hitting close to 0 dB on the A2D’s analog input meters. I set the converter output controls to where the level hit -2 dB on A2D converter’s meters and the TASCAM H2PA-Flash recorder meters.
The audio results were excellent — with extraordinarily clean and quiet preamps. The API sounded as good as my reference True Systems P-2 Analog microphone preamp, combined with my reference Benchmark System’s ADC-1 converter. Recorded playback through the TASCAM and a Benchmark DAC1 Pre revealed clean, detailed, transients in the flat picking of my various guitars . The sound had a great sense of space in stereo (pat myself on my back as well for a job well done in the mic placement department).

For pros or audiophiles
Thanks to the routing design of the API A2D, it can be a great tool for audiophile archivists, or anyone who needs to make high-quality PCM copies of analog audio. LPs, analog output of SACD or a DVD-A player: I made copies of various sources at 192 kHz including backup copies of DVD-As that are no longer in print and can’t be copied via the digital jack due to copy protection. I did the same for some of my coveted SACDs and audiophile LPS, including West Montgomery's “Full House” 1/2 speed master LP. Since the A2D does not have RCA jacks, I used my high-end Legacy Coda high current preamp’s XLR outputs and connected to the A2D’s 1/4-TRS inputs via a set of hybrid cables. These cables are easily obtained from any online musician/pro or audiophile retailer.

Thanks to THAT Corp.‘s electronics used inside the A2D, the analog and digital specs of the API are excellent with rated noise EIN at -129 dB (mic) and -125 dB (line). At 48 kHz, 96 kHz and 192 kHz, A-weighted dynamic range is rated at -120 dB. The THD + noise is -110 dB. Great specs indeed!

The A/D converter quality is so much better than what you get out of a laptop, which is quite a bit nosier and sometimes not even fully 24-bit. The A2D means no added noise, with as “perfect” copy of the original as you get when copying a another recording via the the analog route. I challenge anyone to hear a difference between a one-generation A/D dub through the API and the original recording.

The verdict
As a combo/microphone preamp A/D converter, I don’t think you can do any better in terms of performance than the API A2D. Its professional connection options mean you have to use XLR, or hybrid cables, but those are not hard to get. Its 1RU rack size allows it to fit perfectly in a home recording rig, or with the addition of some stick-on feet, it can stack nicely on your audiophile gear. Since I used it with a standalone recorder with compatible inputs, it was no problem connecting to the API. However, If you want to go straight into a computer, you will need some type of interface that takes AES/EBU XLR or RCA SPDIF input signal (there are plenty out there). It would be nice to see API add a USB 2.0(3.0?) or Firewire interface to the A2D.
In a nutshell, this is API’s only digital product and they made it a dandy. Stellar Sound Award for sure. For more info visit,

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