What's the difference? (3.5mm VS opitcal)

Anthony_F_Thompson

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So I had a though. I can't find many 2 channel receivers on the market these days except for maybe eBay retailers and such. I know, its out dated. But I still like 2 channel but I wouldn't be bothered if I had to update. AND no I do not want to go with a PC theater system with a bunch of speakers that plug in directly to the back of my sound card (front, center and surround 3.5 jacks yata yata). I'll take a receiver with powerful speakers and an optical cable, thanks. Here's where I got curious, though.

What is the difference (when having just a 2 channel set up) between plugging a 3.5mm audio output on the sound card to the RCA inputs on a receiver VS plugging an optical cable in the sound cards output to the receiver's input and using just 2 channel.

I know the 3.5mm output has no use of encoders, but what does that count for the audio bit rate when being passed through a receiver? The optical options has the choice of no encoder (Probably PCM) and DTS or Dolby (We're going with PCM, obviously). Do they both playback on the same level of 2 channel PCM or optical the full output 2 channel audio can go vs using analogue 3.5 to RCA? Or is it the other way around?

Not that I will certainly need to use the one for surround set up on a receiver, of course.
 
Solution
Going from 3.5mm to a stereo, the signal has been converted from digital to analog by your sound card or phone or MP3 player or whatever. Probably a rather cheap DAC that will introduce noise. Keeping it optical or digital to the receiver and letting the receiver decode it to analog will usually have a better signal path as a decent receiver may have a better DAC than your sound card.

Now a $400 sound card vs a $100 receiver may negate this, but a built-in motherboard sound vs a $500 receiver, the receiver will probably have a better signal.

In addtion, a lot of 3.5mm jacks are used for headphones and thus amplify the signal and will introduce distortion.
Going from 3.5mm to a stereo, the signal has been converted from digital to analog by your sound card or phone or MP3 player or whatever. Probably a rather cheap DAC that will introduce noise. Keeping it optical or digital to the receiver and letting the receiver decode it to analog will usually have a better signal path as a decent receiver may have a better DAC than your sound card.

Now a $400 sound card vs a $100 receiver may negate this, but a built-in motherboard sound vs a $500 receiver, the receiver will probably have a better signal.

In addtion, a lot of 3.5mm jacks are used for headphones and thus amplify the signal and will introduce distortion.
 
Solution

Anthony_F_Thompson

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Yeah, I don't use headphones any more. I'm using Creative's T40 2.0 speakers. The sound card I'm using is a Soundblaster Z and will be upgrading to the AE-5. I enjoy the SBX Pro sliders my current sound card has and I can still use it though optical (but it removes bass slider, obvious reasons here) and I just love the way it sounds and I'm sure the next card will have something similar. I got this for my living room recently. As far as I can tell every thing sounds amazing compared to my old samsung which only had Dolby Prologic 2 and an old DTS decoder and trying to use PCM would only do 2 channel because the HDMI input/output was broken and it would have only been able to do 1080i any ways which is a NO for me.

So with a $150 sound card an a $150 receiver (That's how much my Sony STR-DH550 5.2-Channel AV Receiver cost) using an optical cable while having my settings set to no encoder ( https://gyazo.com/4887b29233ddc9b32cefbcdddef1717e ) will most likely be x amount of times better than using a jack, right? It will be straight PCM bit rate on any channel?
 
D

Deleted member 217926

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I'm confused as to why you'd want or need a separate receiver with powered speakers? Just plug the speakers into the sound card.
 

Anthony_F_Thompson

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Because high end speakers don't come with 3.5mm jacks. And I doubt a sound card would be able to power them all.
 

Anthony_F_Thompson

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I'm mostly just looking for a straight answer, not a particular item.

To make the question more clear.

The receiver I have in my living room has the option to switch from Dolby True HD, DTS HD and pure input where it just uses PCM with no encoding or filters.

My sound card also has the same options weather or not its plugged in via optical or while using the front speaker 3.5 port.

While using the no encoding/PCM option on both receiver and the sound card, will I get better signal/audio output VS using 3.5?

(Keep in mind that this is only a 2 - 2.1 channel set up idea, I know optical does not support PCM on 5+ channels).

My PS4 has the same options but its a slim so they removed the optical output so I know for sure that the HDMI is outputting the best audio possible since I have it set to PCM and not any of the bit streams.