A few questions about DAC basics


I have been making a few upgrades to my system and a friend suggested that I consider a decent used DAC as a good upgrade. He was not really sure if my CD/DVD player could use a DAC. He has very high end equipment and has separate transport/DAC etc. Guess he hasn't slummed it with off the shelf integrateds for awhile:)

Here is my system:

My system is:
Denon 5 ch DTS receiver (1801)
Parasound 1000 hca amp for the fronts only
RBH Sound 61SE fronts
RBH 661SE Center
Polk Audio S6’s for rears
ACI Titan Sub
Pioneer Elite DVD/CD player DV-C36
DH Labs T14 silversonic speaker wire
Tekline TL 2000 RCA interconnect from the Denon L/R preouts to the Parasound amp
Glass Toslink digital cable from Pioneer to Denon

My first question is can I add a DAC to this system?
I am assuming that the Pioneer d/a converter is what I am using now when I play CD's.
I have coax, optical and regular RCA outputs on the Pioneer.
Presently using a Glass Toslink to the optical in on the Denon. The Denon has two optical ins, a digital coax in, and several RCA analog pairs in, as well as additional Ext. in for 6.1.

My second question is more like several and I apologize if it is too simplistic. From reading these forums it seems that an external DAC is connected from a digital output from a CD or DVD player and then has outputs that go into the preamp, or in my case the Denon DTS receiver. Does the DAC connect to the preamp via analog in or digital in to the receiver?

I am also assuming that the DAC handles the digital signal in such a way as to improve or expand it? I read stuff about upsampling, etc and it sounds very interesting.

Another question I have is what happens when I am playing a DVD? This is where I start to get confused.When I am playing a DVD right now, the Pioneer sends the DTS or Dolby Digital signal to the Denon for processing into 5.1.
Does adding a DAC still allow this process? I mostly listen to music, but still want to watch movies in 5.1 dts or DD sometimes.

Finally, is this a reasonable upgrade for this modest of a system, and do you have any suggestions for around 3-500$ used?

Thanks for your input and patience. I have improved my system quite a bit from the info on these forums and appreciate the expertise here.
lkdog
Ok, first of all I want to thank everyone for all the great information I have recieved from Audiogon! This is my first time giving advice so here goes.

Using a Dac with your system should be pretty painless. First make shure the DAC you buy has a digital out. All you have to do is run a cable from the digital out on your DVD to the digital in on your DAC. Then run cables from the analog out on the DAC to the CD input on your reciever. This gives you your upgraded CD signal.

Now for your home theater siginal. Now, from the digital out on the DAC, run a cable to the digital in on your reciever. This will give you the 5.1 signal. The original signal will (or should) pass through your DAC unchanged. Just select CD or DVD on your reciver to get the correct siginal.

As far as DACs in your price range, maybe others can help more than I can. I use Theta, but there are many others out there.

I hope I have helped, if you have any questions call me at 1-631-209-0814.
Thanks for the responses. Sorry if these questions are pretty basic.

So, it sounds like if I want to have a better two channel signal for playing regular CD's the DAC needs analog outputs.

If I understand correctly, if I also want to be able to preserve using the DVD for home theatre the DAC will also need a digital out that goes to the digital input on the receiver. The DAC is that case does nothing to the signal except serve as a pass through to the receiver?

If that is accurate then that is pretty simple. I will need a DAC that has both analog and digital outputs. I guess I would also prefer it has both toslink and coax inputs as this new glass toslink I am trying has been a wonderful upgrade.

Oh, is there a noticebale difference in general in the upsampling capability from 96 to higher (132, 192)?
My CD/DVD player does output a 24/96 signal in DD and DTS. I don't know what it does to the signal in playing regular CD's which are 16/44; I am guessing it just defaults to the source signal level in that case.

Any suggestions on a decent DCA that has the needed features is welcome. I see several used ones on Audiogon that are in the price range of 3-500$. I will, of course, read other threads for similar requests for buying suggestions.

Thanks again.
Your DAC shouldn't need a digital out because you can just leave the Pioneer connected to the Denon via the TosLink and use the digital coax for the DAC. What I'm not sure about is what the DAC would do when you play a surround DVD - early (stereo) DACs put out a terrible sound in that case, so you would have to be careful. You may be able to control which bits go where via setup in the Pioneer.

As in all things, implementation is more important than the technology, but upsamplers can indeed sound "smoother" if your system and hearing are up for it. I'd say a Perpetual Tech P3A would fit your needs.
Mrowlands - Thanks for the response.

Good suggestion about using both the digital coax out and the optical out from the CD/DVD player to different "destinations" as this would not limit my choices to having to find a DAC with digital out for pass through to the Denon.

I have never used a digital coax, but I know there are many well regarded reasonably priced ones out there. I just switched to this glass toslink from a plastic one and the change was very significant.

I have had my friend also recommend finding a used Perp Tech unit. I will read up on them.
Lkdog,
I must caution you against buying a new DAC for your system. My return to 2-channel audio was through home theater, so I went through a similar process to yours. I enjoyed watching movies, but my primary focus was music, so I wanted to improve my 2-channel (music) performance.
Unfortunately, budget-minded receivers like your Denon AVR-1801 do not have an analog bypass circuit. In other words, your new DAC would output an analog signal which would then go into your receiver. However, the receiver converts all incoming signals back into digital to allow for digital volume control and digital surround processing (DTS, Dolby Digital, etc.) Thus, you are still relying on the DAC in the Denon for the final analog signal that will go to your speakers.
If you are serious about improving your music performance, I would look into a good, used 2-channel pre-amp to use with your Parasound, thereby taking the receiver out of the 2-channel loop. You can then input the DVD player (or new DAC) into the preamp, and connect the preamp to your Parasound, then the speakers. The movie output (via the TOSLINK) will still go to the receiver for processing and then the center and rear channels. I hope I am not confusing you, but you really can have the best of both worlds (with some compromises, of course).
If this is a larger bite than you can chew right now, a simple, cost-effective upgrade would be to buy a good-quality, used coaxial cable to connect your DVD to your receiver. I think you will find an improvement over the TOSLINK.
I realize that the complexity of combined HT/2-channel setup can get confusing, but it can be done with decent results. These are some of the lessons I learned (the hard way) when I was in your shoes. I have since seen the light, and have whole-heartedly converted to the purity and resolution of 2-channel! Can I get a witness? AMEN!
Enjoy your system, and remember - HAVE FUN. Good luck.
Mark