The Crescendo Tuner/USBDAC is an extremely interesting and innovative product. It is not just a Tuner but also includes an entire high performance USBDAC section. The Crescendo Tuner/USBDAC can be seen as two different audio sources combined in a single piece of equipment, each source corresponding to a different working mode: Tuner Mode and USBDAC Mode.
The specific circuits for each mode are completely separated physically and just one section at a time is supplied, according to the selected mode (This avoids any kind of interference between the two signal paths). Instead, the analogue output stage is the same for both of the modes. Everything has been realized according to the well known Audio Analogue experience. The power supply is based on a toroidal transformer and each section has its own voltage regulator stage.
The tuner is based on a high performance circuit already used by Audio Analogue on its tuner products. The whole tuner section has been realized in a metallic separated box to shield the RF interference and a special buffer stage has been put between the tuner section and the output stage to further decrease the RF noise.
The USBDAC section is composed by a dedicated section which, working on the USB data, supplies a SPDIF digital audio signal. The digital audio signal is then converted into an analogue one by a high performance DA section composed by: a 96 KHz/24Bit, very low recovered system clock Burr Brown receiver (residual jitter less than 50ps!) and a 24 Bit/192KHz Enhanced Multilevel Delta Sigma architecture DAC (The conversion circuit is placed on a separated board to avoid any high frequency disturbance on the audio signal).
The Crescendo Tuner/USBDAC is controlled by a microcontroller and both the switches on the front board and the remote switches have different functions depending on the mode the unit is working on. The Crescendo Tuner/USBDAC has a very reliable low emission display to not interfere with the audio signals.
All the components, passive and active have been chosen considering their electrical characteristics and sound performance too.
The USBDAC permits you to connect the Hi-Fi system to the PC or MAC via a USB connection. In this way the PC/MAC sees the Hi-Fi system as its audio board and everything which is played on the PC/MAC is reproduced by the Hi-Fi System. This opens up a wide spread of possibilities which we think will be soon appreciated by every, also “old style”, audiophile:
• Listening to tracks in any format (MP3, WMA, FLAC, APE and so on…..) which you have in your PC via a software player. In such cases, according to the player, you can also control the PC (Next track, Previous track, Play, Stop, Pause) by the Crescendo Tuner/USBDAC front switches or remote.
• Listening to an on-streaming tuner. On the web there are a lot of tuner stations which transmit on-streaming, so a lot of stations from everywhere in the word can be listened to.
• Listening to audio movie tracks which are playing on the PC.
The Crescendo Tuner/USBDAC has also a SPDIF Out which can be sent to an external DA converter.
The Crescendo Tuner/USBDAC has both the Trigger In and Trigger Out connections so it can be switched on/off by another unit of the chain and also can switch on/off another unit of the audio chain. | 
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