Optical Why Does Everything Have an Out Nothing an In

[sammie]

Ok, I exagerate, but it does perplex me that just about all CD and DVD players(even the cheapo semi-disposable ones) come with digital opitical audio out, yet only the highest end amps/receivers have opitcal in? Anyone know why?

[SaSi]

Interesting question.

I guess that even a low-cost player can "afford" to have an optical output, which takes digital data as read and streams them out. They also have a "low-cost" D/A converter to provide you with Analog outputs.

Low-cost amps equally, take the analog input and amplify it. Only high-end models can "afford" to incorporate a high quality and expensive D/A converter.

So the idea is that if you want a high quality D/A converter, you buy one inside an expensive amplifier. If your budget is low, you settle for the low-cost one in the DVD player.

[sammie]

I was making various arguments like SaSi's to myself, but I couldn't come up with one that was really satisfying. The bottom line is that it argues that D to A converters that work on CD/DVD players are for some reason much less expensive that those that read the input stream from a optical-in. Seems kind of unlikely. It could be a quality thing, but knowing about bit about sound circuits and chips, I don't really understand why that should be either. Unfortunately, nothing much comes with a schematic anymore so I don't know that the D/A chips are that devices are using. Plus, I don't have an amp with an opital in (thus the question actually).

[Gazorgan]

Optical out, and DTS for that matter, are simply pass throughs. No decoding is done, hence no licensing fees. To decode the optical, you would have to pay the AC5.1 licensing fee, same for DTS. This adds incrementally to the cost. You also need the high end D/A Convertors (cost more $$$). This shifts your from a cheap stereo to a more expensive one.

[sammie]

Ok, but don't you still have to decode the digital signal to "read" the disk and generate the analog out? Plus, most of the amps/receivers I've looked at are moderate priced but designed for "home theatre" so they are already do DTS decoding and I presume therfore have paid any fees. I understand that higher quality D/A chips would cost more, but why would they be that much more expensive than the D/A in the player?

Just seems really odd that you have to get an amp pushing $1000 to get optical in. Cheapest I saw at the local Best Buy yesterday was $799. I can understand it doesn't come on the $299 all in one system, but why not on the $300 - $500 units that make up the huge majority of systems sold.

[rvl123]

Ok, but don't you still have to decode the digital signal to "read" the disk and generate the analog out? Plus, most of the amps/receivers I've looked at are moderate priced but designed for "home theatre" so they are already do DTS decoding and I presume therfore have paid any fees. I understand the higher quality D/A chips, but why would they be that much more expensive than the D/A in the player?

Just seems really odd that you have to get an amp pushing $1000 to get optical in. Cheapest I saw at the local Best Buy yesterday was $799. I can understand it doesn't come on the $299 all in one system, but why not on the $300 - $500 units that make up the huge majority of systems sold.

My Denon AVR-2802 has 2 optical ins and 1 Co-Ax in.

It retails at $799. A great amp for the price.

[sammie]

@rvl123, exactly my point $799. I've got a great Onkyo, you can still get it for around $399. Virtually the same amp with optical in is $899.

If that kind of price difference is license fees, can you say shooting yourself in the foot.

[Metaluna]

Just seems really odd that you have to get an amp pushing $1000 to get optical in. Cheapest I saw at the local Best Buy yesterday was $799. I can understand it doesn't come on the $299 all in one system, but why not on the $300 - $500 units that make up the huge majority of systems sold.

I'm a little confused here. Are you talking about standalone amps or receivers? And are you talking about Audio or A/V "home theater" receivers? If the latter, then I'm pretty sure that virtually all A/V receivers have at least one TOSlink optical input. Here's a Kenwood model I found on the Best Buy website that has one optical and two coax digital inputs, on sale for $170.

http://www.bestbuy.com/site/olspage.jsp?id=1051826210092&skuId=5391426&type=product&pr...oryId=cat03031

Here's a $130-ish model that also has an optical input:

http://www.bestbuy.com/site/olspage.jsp?id=1051384838207&skuId=4384614&type=product&pr...oryId=cat03031

If anything, if you look at mid-to-high end A/V receivers that have large numbers of digital inputs and flexible input switching, the trend is away from coax and towards more optical inputs (e.g. Denon).

[sammie]

Interesting, I'll admit I wasn't looking at the lower end models so I don't know if I saw the models you mentioned or not. I was looking at both home theatre and audio models. Went to Circuit City, Best Buy, a local high end audio store and Fry's. I didn't see a single model with the optical (or coax) input for less than the $799 (with most considerably more). Ok, shoots the hell out of the they cost too much argument. Still leaves the question where are they on the mid-level units.

It also adds a new twist. The two units you show are what I would consider low end home theatre receivers. Is there a bias against the optical input in the audio world? I didn't check out all the CD players, but both CD players I have have optical out so it would seem not.

[sterno]

When you start to look at the real high-end stuff your whole sense of scale has to change to match. Good analog/digital converters are actually pretty complex to design, and high-end receivers will have the more expensive versions. You also have to remember that the optical input itself isn't as simple as an RCA jack where you just make metal touch metal, and again higher quality costs more.

Think about cars: some cheap economy cars in the US can be bought with all the options for $15k, but if you want a luxury or sports car your baseline model with no options will often cost over $20k. Your expectations have to change to match what you're looking for.

If you're looking to buy, maybe you need to step back and figure out what you're looking for that the "low-end" models don't have. And do a little research, a good low-end model sometimes has better audio quality than some high-end receivers, but doesn't have some of the bells and whistles.