If you are searching for a professional audio grade soundcard for your next project, you may be interested in the Audio Injector Pro, recently launched by a Kickstarter. The Raspberry Pi compatible soundcard can be used with a wide variety of different devices and is available from just £31 or AU$55.
“Following on from our success with the Isolated sound card we realised that some people want super high definition audio at a lower cost. Some members of the Audio Injector community have also said they were interested in a phono analogue skin. Here are our latest technologies, the Audio Injector Pro soundcard with analogue phono preamplifier.”
– Raspberry Pi 40 pin standard header (suits Pi 0, 2, 3, 4 & expected future versions)
– Main soundcard with all input, output and mute codec lines broken out
– Main soundcard with +-12V and phantom power lines provided
– Main soundcard with GPIO lines broken out for preamplifier control
– RIAA phono preamplifier (skin). Soundcard and preamplifier are sold separately post Kickstarter.
– Preamplifier board can be changed for different ones with other features, such as our balanced XLR preamplifier and our RCA preamplifier.
– We have future proofed the preamplifier connectors to allow all sorts of different designs to be made, for example microphone preamps, headphone amps.
– Build your own preamplifier PCBs and attach them (implements the Audio Injector Analogue Breakout Standard v1)
– Integrated into Linux (for Rasbian – Raspberry Pi) and the ALSA machine driver is easily ported to other Linux based embedded systems.
“The sound card implements the AI-ABS v1 analogue breakout specification. It provides balanced inputs, outputs and mute lines. It has a GPIO header with 5v power. It also provides power rails for driving preamplifiers (+-12 V) as well as phantom power.”
“The phono preamplifier implements the RIAA transfer function which equalises vinyl to have a flat spectrum. It has RCA inputs connectors and RCA output connectors. The phono preamplifier also implements the AI-ABS v1 analogue breakout specification. This preamplifier can be used with other soundcards that implement the AI-ABS.”
– 192 kHz sample rates, 24 bit audio words, using the cs4272 codec
– Balanced preamplifier with RCA connectors all pre-assembled
– Ships with a 40 pin header assembled, a second header slot on the sound card not assembled (for you to use).
– Professional level signals
– On the chip audio mixer to control the sound levels and features.
– Relays as muting circuits – ensuring popless & silent reboots
– DC coupled sound card inputs and outputs – no AC coupling caps.
– The phono output is also DC coupled – no AC coupling caps. The phono input does have AC coupling (through film capacitors).
– 0 Hz to 96k Hz analogue bandwidth
– Main sound card DAC Full Scale (FS) peak to peak output voltage : 4.8 V
– Main sound card ADC FS peak to peak input voltage : 5.65 V
– Main sound card closed loop gain (4.8/5.65) : -1.42 dB
– Inverse RIAA preamplifier gain : around 50 dB
– FS voltage levels are accurate to the tolerances of the cs4272 codec (specified in their data sheet).
Source : Kickstarter