Abbey Road Studios, one of the world's longest-established and most highly respected recording companies, has taken delivery of four NTP DAD AX24 eight-channel ultra-high-quality analogue-to-digital/digital-to-analogue audio signal converters. All four will be deployed during recording sessions as microphone preamplifiers and analogue-to-MADI interfaces. They will be operated in conjunction with Abbey Road's Pyramix digital audio workstations. Two of the units are additionally fitted with the IO192-PHD interface card allowing them to work with Avid Protools.
"The AX24 units have been purchased primarily for use by our mobile recording unit," comments Simon Kiln, Head of Editing at Abbey Road and a producer of recordings both in the studios and on location. "They give us the benefit of exceptionally low-noise analogue signal preamplification, high quality digitising and considerably shorter setup and dismantling times. We have been trying to build affordable recording packages for many styles of music. Key to this was the ability to set up quickly without compromising the quality people expect from Abbey Road Studios. Our equipment is transported in flight cases to wherever it is needed and then set up with an onsite control room. Putting kit in place to record a medium-size orchestral production can easily take three hours and includes running as many as 30 microphone cables out to the control room. The four AX24 converters allow up to 32 microphones to be combined into a single MADI channel and routed to the control room as just two cables: the MADI feed itself plus wordclock timing reference. They also give us the ability to adjust the level of each preamplifier channel from a laptop PC or digital audio workstation in the control room.
"Having one box that performs preamplification, analogue-to-digital conversion and MADI integration has greatly improved operational efficiency," adds Abbey Road Senior Recording Engineer Jonathan Allen. "We also wanted the option of working at higher sampling rates and, after comparing it to other converters, I found the AX24 made one of the best cases for working at 96 kHz and above."
"The DAD AX24 has the quietest front-end amplifier we have ever tried," details Arne Akselberg, Abbey Road Senior Classical Engineer. "Comparing the AX24 with other brands, the difference was astonishing. And it is one of the few such devices that sounds really good at 96 kHz."
The four AX24 signal converters were supplied via NTP Technology's UK distributor, eMerging, which also supplied the Pyramix digital audio workstation used by Abbey Road Studios as a mobile recorder and editing system.
Designed for high quality music recording as well as mastering and monitoring in DSD, the NTP DAD AX24 offers A/D and D/A conversion in PCM at up to 384 kHz sampling rate, DSD at 64 frame/s or 128 frame/s, and 352.8 kHz DXD. The optional microphone preamplifier incorporates analogue gain control in 3 dB steps as well as digital gain control with 0.25 dB precision. Dynamic range is between 118 and 121 dB. The preamplifier's equivalent noise floor is -130 dB.
The AX24 is fully remote controllable via RS-422, USB or Ethernet. Preamp parameters can be represented on the channel strip of industry-standard audio production consoles and workstations. MADI output is configurable to operate in loopthrough mode, connecting multiple converters to a single data output. The interface can be set to access any configuration of 64 MADI channels in blocks of eight consecutive channels. The AX24 can be synchronised to incoming AES 11, Word Clock, Super clock or video (PAL, NTSC, SECAM). An integral phase-locked-loop circuit is able to correct for minor variations in external sync timing.
Existing users of NTP DAD audio signal processors include Bauer Studios, CMC Studios, Danish Radio, DEX Mastering, DPA Microphones, Galaxy Studios, Lindberg lyd, Master Touch, McGill University, Moscow Music Conservatory, NDR Hamburg, NHK, NRK, Real Sound, Royal Danish Opera House, Royal Opera London, Sidney Opera house, SK Works, SoundWorks/Jeff Sheridan, Spanish Radio, St Petersburg Philharmonic Orchestra, Stock Fish Records, Swedish Radio, Telarc International, Ultimo Productions and the Warsaw National Philharmonic Orchestra.