Transport question

mca · « **on:** 15 Oct 2005, 07:28 pm »

Thanks to Chris Own, I had a chance to evaluate an Ack! Dack 2.0 at home for a few weeks. I found it hands down a better sound than my Ah! Njoe Tjoeb 4000 cd player. The Ah! is now going up for sale to raise money for the Ack!

My question on transports has to do with the trend of using DVD players. I know the old Sony 7000 and 7700 are very popular to mod. The cheap Toshibas also seem very popular. What makes the DVD platform so good as a transport?

I found a couple of great deals on both a Rega Planet and an old Acurus ACD-11. I like the looks and build of both, but it sounds like it's not worth spending the extra money.

mca · « **Reply #1 on:** 17 Oct 2005, 04:09 pm »

No one knowledgeable on transports?

PhilNYC · « **Reply #2 on:** 17 Oct 2005, 04:27 pm »

I think the main things about transports are that it has low/no jitter, and that the SPDIF output is a true 75ohms. From my understanding, the low/no jitter thing is mostly impacted by the clock, the actual transport mechanism and laser, as well as the power supply. I guess that's just about everything!

The true 75ohm thing is hampered immediately by the use of RCA jacks, which are not true 75ohms. I've definitely found that even just using a BNC connector on the DAC side of the digital cable (while still using RCA on the transport side) to be better. Also, per Steve Nugent's article on Positive-Feedback.com, using a digital cable of 1.5m or more also helps reduce the impact of signal reflection on jitter going into the DAC....

One DAC manufacturer told me that he prefers DVD players as transports, because the laser mechanism is more accurate, so using it on a regular redbook CD will result in a better read. He also said that about an SACD laser reading redbook CDs...

audioengr · « **Reply #3 on:** 17 Oct 2005, 05:37 pm »

The reason that I like the Sony 7000 and 7700 is that they both have two lasers, and the CD laser is better at reading the CD pits. AS Phil mentioned, the drives also have more accurate tracking mechnisms and servos. The 7700 is newer and most of them have less hours on the laser. It is also more highly integrated, so less parts to fail.

rbrb · « **Reply #4 on:** 18 Oct 2005, 11:42 pm »

Is it not true that the average DVD player (low cost mass market Sony, Panasonic, Tosiba etc) would have much more jitter in the signal compared to a better CD player (Rega, Acurus) ?