The chassis of the CD 303T SACD Pro is divided into three functional zones. This compartmentalization was designed to keep the different sections from interacting with one other as they each perform their individual functions. As you can see, the sophisticated power supply occupies the entire left side of the chassis. In this section, the power enters the unit through the IEC connector and is sent through the individual C core transformers, then to the numerous 12 and 15 level precision voltage regulators for the analog and digital circuits. Both the analog/digital section and tube output of the CD 303T SACD Pro receive its own C Core transformer which is independent from all others. In this way we can ensure a stable and clean supply of power to the digital and analog portions of the circuit.

 

 

 

The differences between the CD 303T SACD Pro and CD 303/300 it replaces are certainly more than skin deep. The internal differences are what truly make this unit shine. All internal circuits were updated in the 303T from the power supply to the I/O board. As described above, multiple large power transformers with higher current regulators provide a stable solid power source for all stages of the CD 303T SACD Pro. All internal components are rated for 105º C operation which ensures their stability regardless of the environment and promises they will hold strong after many years of use. The temperature inside of the CD 303T SACD Pro will likely never reach such levels, but the additional headroom ensures an extra level of reliability and performance.

 

 

The center portion of the chassis houses the aluminum disc transport mechanism as well as the SACD and DAC circuitry. This transport is machined to extremely tight tolerances from the highest quality billet aluminum. It allows the disc to be rigidly clamped in place so that the laser assembly can read the data without zero errors.

The large illuminated display on the front panel shows the disc and setting information. This includes the disc type, track information as well as sampling rates and input and output settings. When used as an external DAC, the CD 303T SACD Pro will show which digital input is active and the sampling rate selected. All of these settings can be controlled using the included infrared remote.

 

 

The Analog circuitry in the CD 303T SACD Pro is housed in the right portion of the chassis. This single board includes the components for both the solid state and vacuum tube analog outputs. The analog audio can be output over both the single ended RCA and fully balanced XLR jacks.

 

The tubes used in the analog section are user replaceable. A small access hatch is mounted over the 4 tubes on the analog board. (x4) 12AU7 tubes are mounted in ceramic sockets and can be changed to suit your listening tastes. Changing and experimenting with different tubes has become known as “tube rolling”. Experimenting with different brands of tubes is easy and can impart subtle to dramatic changes in the sound.

 

 

 

You can use any ECC82/12AU7 tube, or one of the many military variants available. Several vendors on the internet still have supplies of vintage tubes from the 50s and 60s from RCA, Telefunken and Mullard. The possibilities are endless!

 

 

The rear panel houses all the input and output jacks for the CD 303T SACD Pro. The top row shows the three digital outputs you can use to connect to other devices. The ports are for AES/EBU, coaxial and toslink style cables. Directly below these are the three digital inputs. They accept digital signals from toslink, coaxial or directly from your computer using a USB cable. This USB input can accept signals up to 24 bit/192 kHz to support today’s hi-res music files. Once converted, the analog audio signal can be routed through the solid state or tube output section.