Help for RDV1080 modification

[aarsoe]

I have the RDV1080 DVD player - which in my oppinion is a nice player, but have (at least) one serious fault.. They forgot to put in two analog outputs for Right and Left channel and ditto for two coax digital outputs.

Does anybody know if I can just add more phono plugs in the back of the cabinett and daisy chain them?

Have asked Rotel, but they where not sure as this could change impendance on the outputs.

The reason that I want two digital outputs are one for home theater and one for my external DAC.

The reason that I want two front channel outputs are one for DVD audio (using the 5.1 input on my 1066) and one for normal CD playback.
I know some of you will ask, why this when I have the DAC - but on some CD's my DAC are best, one others vice versa..

[Andrew Pratt]

I moved this thread into here in hopes that maybe Jon could speak to the issue

[JonMarsh]

Adding an extra set of analog connectors would probably not pose any problems; though I'd recommend being very careful about drilling the rear panel to keep metal chips and dust out of the circuitry.

The digital output thing is rather a bit more complicated an issue; 75 ohm coaxial outputs have a required source impedance (75 ohms) and a required terminating impedance at the load (75 ohms, of course! :W ), and you can't parallel an extra set of connectors and hook them up to the one source; it will overload the one transmitter, and create impedance reflections which will degrade the SPDIF signal.

Usually to add another coax or toslink output requires driving an additinal buffer amplifier off the chip output- it is possible to get toslink transmitter modules, but finding the right connections in your Rotel for power and signal are not reasonable tasks for a novice in electronics.

For the digital audio, if you need to drive two different sources, but not simultaneously, you could get an inexpensive video switching selector box; these are 75 ohm impedance, also, and could work to select between different units to send your digital SPDIF signal.

Curious, what DAC are you using, that you think the DAC is sometimes better, and the Rotel sometimes better? I do not dispute your evaluation of them, it just makes me wonder if your problem isn't that each has some strengths and some problems, possibly the outboard DAC suffering from not running on the same master clock, and not having the jitter rejection of more expensive DAC's. Maybe the solution is a better outboard DAC...

Good luck getting things sorted out.

Best regards,

Jon

[Andrew Pratt]

thanks Jon

[aarsoe]

The DAC I am using is a Parts Connection Assemblage 3.0 Dont know if you know it, but it used to be a company that made DIY audio products and was in fact a Sonic Frontier company.

Why there is a difference eludes me as well, as the DAC 3.0 should be a huge improvement over the 1080 - but my guess is that if the recording is close to perfect, then the external DAC is best - and on the other hand if the recording is not, then it is the other way around.
Let me give you an example. Diana Krall recordings are generally pretty good and sound good on both, but is by far better on the external DAC. However the No Doubt Singles album sounds pretty horrible on the external DAC, but ok on the 1080..
I am guessing that it all comes down to that unlike what I normally see or hear at HiFi shows, I don't only listen to special recordings of less famous artists - Honestly I even have to accept my 5 year old daughter playing Britney S. - and most of her recordings was made for car listening.. Anything to help ease the agony..

Guess the best thing to do would be to go back to my former setup, using the 1080 as a DVD/bad recordings drive only and re-install my cd player hooking that one to my external dac. It is a shame though, as the 1080 actually, in my oppinion, is a pretty decent drive and the whole idea was to cut down on the already huge number of boxes I have..
But as a general comment - Rotel should install 2 front outputs on all their players...

Thanks for the move and reply :T

[JonMarsh]

That's interesting- the Assemblage DAC 3.0 is a very good unit, in general, and if I recall correctly, uses BurrBrown PCM1702 DACs, with a Crystal 8414 reciever. They also offered an outboard unit to use with it, which was an upsampler/de-jitter box using the Crystal 8420.

I understand in principle what you mean about the difference between good reference recording and pop recordings. There's certainly a garbage in, garbage out issue at work.

OTOH, I've noticed that as my playback system has improved, especially with regards to jitter reduction in the transport and DAC, even those "nasty" pop recordings sound better and less grating- my current rig does pretty well with both fare like Dianah Krall and Patricia Barber as well as artists like Liz Phair and Avril Lavigne. This has been rather transport dependent; even my monster 55 lb Sony SCD777ES is something less than stellar as a CD transport, in my opinion, compared with an extensively modified Philips which I have.

Now, just two other points to cover-

1) DVD players don't make very good transports. They have to use multiple clocks with phase locked loops to pull everything together because of the conflicting reuqirements for CD and DVD. As a result, jitter levels are pretty high- I wouln't recommend a DVD player as a transport for your DAC 3.

2) A few new DACs using Asynchronous Sample rate conversion are showing much better jitter rejection of transports than I've ever seen before- see the published test results at Stereophile for the Benchmark DAC1 which I summarize in the Audio hideout- 128 picoseconds peak running on a toslink (optical) connection from a PC! That's literally staggering performance.

For you, I'd suggest a better transport, perhaps using a dedicated CD player as the front end. But if that's something that would approach $500 or more, then I'd seriously consider a product like the Benchmark DAC1, if you're a dedicated music listener and it's worth the money to you.

I'm probably going to order one this week myself, and I'll be reporting back on the forum what I think about it compared with my home brew DAC and storebought gear.

Best regards,

Jon

[Andrew Pratt]

1) DVD players don't make very good transports

Didn't the Sony 7700 have jitter values that rivaled some expensive dedicated CD players?

[JonMarsh]

Not really. It was around 450 picoseconds peak. But many DVD players, especially first generation ones, had jitter in the 10's of nanoseconds or higher. This effectively converted the DAC's from being 16 bit to somewhere between 12 and 14 abit.

[aarsoe]

Andrew

You must be thinking of the earlier Sony model - the 7000.
I have infact also used that as a transport - but since I live in a 230V country, having a step down converter of somewhat questionable quality is not really the best solution..

The 500 USD for a new player does not scare me - after all my DAC did cost several times that. Problem is to find a good drive. If anybody have some recommendations then please feel free to post them..

[aarsoe]

Forgot to mention. I have the signature version with all the bells and whistles upgrades that where availeble at the time..

[Stevepaul]

OT: Copenhagen vacation

Sorry to go OT here but I noticed your Copenhagen address: a bit of humor.......

Back in the summer of '92, my wife and I spent 3 weeks in Copenhagen for vacation (I am from Michigan, USA). We went with some older friends who had grown up in Copenhagen. During the days and evenings this couple would take us all over the city, showing us the sites.....Tivoli, etc.

One day they took us to the beach. I walk out onto the beach and find myself surrounded by women with no tops on....now you must understand that I am from the conservative Midwest! Here I am, with my shirt, long shorts, white atheletic socks, and high top tennis shoes standing in the middle of the beach surrounded by half nude women! Needless to say it wasn't hard to pick out who the "American" was! :rofl:

I stuck out like pink elephant! :loser: I loved the city and to this day I miss that wonderful smelly cheese that we ate every morning!

Steve

[aarsoe]

Guess the real question then is why the ¤%&/ I am spending time on this subject... :lol:

[Stevepaul]

Those tall danish women definitely would cause me to lose some hobby time...when I was a younger man! :boohoo:

May I also add that the residents of Kobenhavn were the most congenial big city folks I have met in my European travels. About the only thing that seemed to upset the Dane's that I met, were the boatload of Swede's from Malmo that would come over for the less expensive cigarettes and alcohol....I guess some of them would have a few too many drinks, on occasion! 8)

Good luck with your audio/video travels.

Steve