Panasonic AD96/AD96M Analog-to-Digital Converters

For the past year, Panasonic's professional audio division conspicuously disappeared, leaving many in the industry scratching their heads. Panasonic discontinued its line of venerable DAT recorders, had little presence at the major audio shows and, for a time, its Web site disappeared - all under the guise of internal restructuring.
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For the past year, Panasonic's professional audio division conspicuously disappeared, leaving many in the industry scratching their heads. Panasonic discontinued its line of venerable DAT recorders, had little presence at the major audio shows and, for a time, its Web site disappeared - all under the guise of internal restructuring.
Product PointsApplications: Studio; project studio; location recording; mastering

Key Features: Eight-channel analog-to-digital converters; eight-channels of mic preamps on the AD96M; 128x over-sampling Delta-Sigma 24-bit/96 kHz converters; four AES/EBU XLR connectors and an ADAT optical output standard; single-wire or dual-wire AES/EBU operation; optional D-sub AES/EBU and TDIF output cards available.

Price: AD96: $2,195; AD96M: $2,495

Contact: Panasonic at 714-373-7200

Plus

+ Sound quality

+ Excellent value per channel

+ Flexible output modes

Minus

- No insert after mic pre (AD96M)

- No peak hold function (AD96M)

The Score: An excellent value in multichannel high-sample rate/high-resolution A/D converters.
While all this was going on, however, Panasonic's Professional Audio Group was definitely not in hibernation. At the winter NAMM 2001 show, Panasonic made a strong and welcome return to the pro audio world, debuting the next generation of the popular Panasonic DA7 digital console, the DA7 mk II.

Also getting notice at the show were Panasonic's new multichannel, high-resolution analog-to-digital converters - the AD96 and AD96M. A digital-to-analog model, the DA96, will be released late spring 2001.

Features

The AD96 ($2,195) and AD96M ($2,495) are eight channel 24-bit/96 kHz Delta-Sigma converters aimed squarely at the growing high-bit/high-sampling rate recording market. The two models are identical, save the addition of eight low-noise microphone preamps on the AD96M. The front panel real estate used by the additional preamp input knobs and phantom power switches on the AD96M resulted in a more basic metering system than the comprehensive one found on the AD96.

Each channel on the AD96 features a 10-point bar graph meter with two view levels: Normal and Zoom. The Normal (coarse) view ranges from Peak to -54 dB in large steps, and the Zoom view ranges from Peak to -30 dB in small increments. A rear panel DIP switch sets the dB level for the Peak level indicator (0, -0.5, -1, -2, -3, -4, -5 or -6 dB FS) and the user-definable Reference level indicator.

The Reference indicator is the third point from the top of the 10-point bar meter and can be set to light at -20, -18, -16 or -14 dB FS. In addition, the AD96 features a Peak Hold function with three settings: off, 2-second hold and infinite hold. Line input level adjustments are made on front-panel trimpots using a mini screwdriver.

The channel metering on the AD96M consists of a single multicolor LED with three level stages indicated by color. Green indicates signal present (above -38 dB FS); amber indicates signal at the user-definable reference level (same settings as the AD96 above); red indicates signal at the user-definable peak level (same settings as the AD96 above).

The AD96M has no peak hold or zoom functions. Mic/line input level adjustments are made on the eight front panel knobs, continuously adjustable from +4 to -60 dB.

From here on out, features described pertain to both the AD96 and the AD96M. Analog input is via eight rear panel Neutrik XLR connectors. Digital audio is output to four male XLR connectors and one ADAT optical connector. The XLR outputs can be configured to eight channels of standard/high-speed single-wire AES/EBU audio (two channels per XLR) or four channels of the newer dual-wire AES/EBU specification (one channel per XLR).

An optional WZ-AESAD card ($399) can be added to access all eight channels of dual-wire AES/EBU data via a D-sub connector. An optional WZ-TDIAD TDIF digital output card ($399) is also available. Use of either optional card requires removing the factory-standard XLR AES/EBU output module. The ADAT optical output remains available and independent regardless of optional output card choice.

The units are capable of outputting eight channels of 16-, 20- or 24-bit digital audio at 44.1, 48, 88.2 or 96 kHz through AES/EBU connectors. The ADAT optical connector (or optional TDIF card) outputs either eight channels at 44.1 or 48 kHz or four channels at 88.2 or 96 kHz (each channel uses two tracks on the recorder at the higher rates).

BNC word clock in and thru/out (user-selectable) connections are found on the rear panel. The units can lock to incoming clock signals at frequencies ranging from 44.1 kHz to 96 kHz +/- 6 percent.

In use

With our bench tester, Bascom King, handling the objective testing (see bench test on p. 28), Iput the two AD models through their subjective evaluation.

I used the two converters on a variety of projects for the last several months with excellent results. Although I had a few complaints, these units provide high-quality audio and flexibility at a reasonable price.

First Iused the AD96 to transfer tracks from a two-inch analog deck into Pro Tools. This was achieved easily and without reference to the manual. Tracks came straight off the analog deck and into the XLR inputs on the converter, and the resulting digital audio was outputted at 24-bit 48 kHz on the four AES/EBU outputs in single-wire mode.

I also dumped analog tracks straight into an ADAT XT-20 using the AD96's ADAT optical port sending 20-bit 48 kHz audio. Again, this operation was easily negotiated and the resulting tracks sounded noticeably clearer and more detailed than corresponding tracks recorded through the ADAT's internal A/D converters. I love it when you can actually hear a difference!

I did use the high-sample rate ADAT optical mode to send four channels of 96-kHz audio to eight tracks on the XT-20 with apparent success. Unfortunately, without the corresponding DA96 to test, I had no way of playing back these tracks. I also recorded two channels of 24-bit/96 kHz audio to my computer using an AES/EBU output on the AD96 running into an RME digital audio card, again with out any hitches or glitches.

I recorded a variety of sessions using the AD96M and its eight internal mic preamps. These sessions included tracking acoustic and electric guitars, bass, vocals, keyboards and percussion. After careful level adjustment, all tracks went to tape (and hard disk) flawlessly.

While not quite as sonically pleasing as other dedicated (and expensive) mic preamps available for comparison, the AD96M held its own, beating out the internal preamps on a Spirit digital and MCI analog mixer. Relatively speaking, at roughly $300/channel including high resolution A/D converter, these mic preamps sound good indeed!

While the two units performed well-producing high-sample rate/high-resolution digital audio with a great degree of options and flexibility - a few omissions in features and ergonomics should be mentioned. First, the lack of external inserts between the mic preamps and converters limits the usefulness of the M model. There were certain times when some compression on the way in to the converter would have resulted in a better signal to tape (and corresponding higher resolution).

This, of course, was especially true of dynamic instruments where initial transients shoot out some 20 dB over the average signal (a timbale and trumpet track come to mind). In these cases, an external mic pre was run into a limiter and then into the AD96M. At this price point, inserts, or defeatable peak limiters on each channel, are more wish list items than complaints, as they would add significant cost to the units.

Also, the addition of a peak hold function on the M model would be extremely useful. After using and relying on the peak hold function of the AD96, its omission on the AD96M model was all the more obvious. The single, tricolor LED for metering does not allow this option, but there is sufficient space for the addition of another dedicated peak indicator (hint, hint).

Summary

Overall, the Panasonic AD96 and AD96M are excellent values and incredibly easy to use. The high-resolution audio they produce is attributable to solid construction, quality parts and innovative circuit design; the resulting performance of these units is hard to fault. One may want to opt for the AD96 and use external microphone preamps if the lack of inserts is an issue - otherwise the low-noise mic preamps on the M model are a sonic bargain.