daj2832 Here is a great read on transports, and how they differ, look esspecially at the scope shots down the bottom of the digital output wave form of the spdif output, here lays the answers. http://lampizator.eu/LAMPIZATOR/TRANSPORT/CD_transport_DIY.html This is my new Cambridge Audio CXC transport I sent Lampizator this pic of it, and he said. https://ibb.co/fXSQKxK " this is as perfect as it gets. and the speed is exactly 1,41 MHz. Regards Łukasz Fikus" Cheers George |
I’m an analog guy in a digital world... but I decided to finally install a digital front end in my main system. I used an Oppo BDP 95 as an interim step, with a Border Patrol DAC. I bought the entry level CEC transport and it sounds better than the Oppo. (The Oppo is a great value for what it is an all in one universal player). So, without having both feet firmly planted in the digital world, I can say as a casual entrant into the field of digital playback, the transport does make a difference. |
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I recently purchased an Atoll DR 200 Signature. It’s a fine unit. That may be another unit you may want to check out. The Atoll transport can be serviced in the U.S. and uses a Teac 5020 CD drive. I believe that drive is also used in the Tascam 200, and appears to be a decent quality unit (certainly not a $15 computer drive). The Atoll unit is built in France, and most of the subcomponents, are also manufactured there. I believe there is more to the transport issue rather than just jitter. Several factors come into play before the data reaches the DAC. The laser must remain in focus and track the disk. The disk must rotate at a constant angular velocity. The HF signal should be as noise free as possible. The transport should be vibration free. Errors with reading the signal and the PCM conversion are corrected on the fly, typically using a Reed-Solomon, or similar correction method. I believe the error correction process and method may also affect the signal. As data are transmitted “on-the fly”, no checksums are involved. There is no guarantee the data will be “bit-perfect” as compared to the source. This is true for disc or computer based systems when the data are “streamed” to the DAC. The signal could also be contaminated with noise, or altered, during transmission. Regardless of your choice, a CD transport with a good clocking circuit, power supply, and vibration dampening should be a priority in my view. I looked at the Sim Audio, but decided on the Atoll as a replacement CD drive may be easier to source in the future (Teac 5020 is a well-known unit). I ended up purchasing a spare drive from Atoll at a nominal cost. In my experience the transport can have almost as much effect DAC on the sound quality as the DAC. However, above a certain level, the transport differences may be smaller. |
