Infrasonic Quartet is one of such solutions, which is designed to replace an external multi-channel interface with microphone and other inputs/outputs. Owing to its functionality, the Quartet also competes with a traditional sound card with an external mixer.
The Infrasonic Quartet actually develops the idea of the four-channel Audiotrak MAYA44 card, which evolved to the ESI MAYA44.
The Quartet is based on the same configuration as the MAYA44 - 4x4 analog inputs. It also uses a stereo jack, TRS, unbalanced, -10 dBV. So you can easily plug headphones and consumer electronics through a stereo mini-jack adapter.
One line-in can be switched to a mic preamp mode with +48 V and a low cut filter (75 Hz). The other can be used as a guitar input. Both line-outs are equitable. They can be used for headphones without switching to the low-impedance mode.
Strong hardware points of the new product also include new promising converters (AKM AK4620B). We've already seen them in the ECHO Audiofire 4 and RME Fireface 400.
The AK4620A is positioned for professional sound cards, DAW, and other equipment. The codec supports up to 24-bit 192 kHz for recording and playback. Signal to noise ratio is 100 dB, dynamic range - 113/115 dBA.
Noise spectrum of PCI sound card depends on interferences that come from power lines, grounding problems, and other factors. The manufacturer of the Quartet card speaks of using a proprietary 'US-PSB class I' technology (Ultra Stable Power Supply Block) to filter power supply. It's based on OP-AMP discrete circuits instead of a general regulator type IC. In addition, it has the function of slowly rising voltage, called 'Slow slope ON'. This protects monitor speakers and headphones from being damaged by that "pop-noise" when you turn on your PC.
Noise Guard Bracket is used to protect QUARTET from electronic noise that the computer and other PCI/video cards can generate. I doubt it - cards without such protection demonstrate similar results. It's a decoration rather than a functional element. Besides, it adds rigidity to the card.
Unusually-looking output connectors have threads and come with plastic nuts, which fix the card in a PCI slot and prevent possible switching problems.
Note the correct distance between the output connectors - you can plug popular rubber TRS Proel connectors. For comparison, the Juli@ card has serious problems with its connectors - you can plug only Neutrik or new Proel connectors (they are smaller in diameter.)
Note the WordClock BNC connectors, which allow to sync the card with other devices. Besides, the adapter also has S/PDIF and MIDI interfaces.
Phantom power applied to MIC-in lights a yellow LED on the bracket near the input connector.
The INFRASONIC QUARTET is a multi purpose pro audio interface card using stable PCI bus technology. QUARTET provides high quality, multi-function, sound editing for your home studio.
QUARTET has better performing analog I/Os than other cards in its class. It supports a 192 kHz ADC sample-rate with full 24-bit recording. The high-quality AD/DA converter has 115dB signal-to-noise (S/N) ratio. The high-end components in the analog circuit improve dynamic range by 10dB.
Other features include a MIC preamp, direct instrument input, MIDI I/O, Coaxial I/O, Word clock I/O and Dual Headphone amplifiers QUARTET is professional gear that will satisfy in features, performance and convenience.