Why do amplifiers typically only have RCA inputs?

[TangledUp]

I am a complete newb when it comes to a/v and am confused about something. I recently purchased a Russound R1250MC amplifier in order to power various zones using Sonos. The Sonos has two digital outputs and an RCA output. The amp has only RCA inputs. I was concerned I got the wrong amp and then researched that almost every amp I saw only had RCA inputs as well.

From what I understand, and I could be wrong, digital inputs are "supposed" to provide a higher quality sound than RCA inputs. If that is the case, then what is the point of even using these optical outputs when an amps connection will just degrade the signal via the RCA inputs? What am I missing here?

 

[steverobertsbbc]

I think you might be missing that you need a pre-amplifier between the Sonos and the Russound power amp?

The Russound is just a power amplifier. You feed a variable level of input signal into it from a pre-amp or surround processor and it provides a fixed amount of amplification to the speakers. Any sound processing or volume control needs to be performed before it gets to the amp.

As to why it needs to have analogue inputs, well at some point a digital signal needs to be converted to analogue in order to amplify it to loudspeaker level. It's generally accepted that power amps are just dumb analogue grunt and the D-to-A conversion is done in the pre-amp stage.

 

[andy1249]

That is the case with most stereo integrated amps as well. RCA inputs only.

AV Receivers are where you have digital signal processing , various other onboard signal processers , video signal processers , and both pre and power amps built into the one unit.
These are by far the most common "amps" sold today , and you can indeed get very good results from them, but not as good as dedicated units.

Stereo integrated and power amps on the other hand , are purer beasts , aiming for a better signal by forcing processing duties out to another box.

To use the Sonos , or indeed Squeezbox digital outs with such Stereo/Power amps , you usually need a dedicated DAC unit.

With Decent RCA interconnects and a good DAC , no need to spend a fortune now , results are invariably better than most recievers.

 

[TangledUp]

Thanks for the information guys. Definitely clears some things up.

I think you might be missing that you need a pre-amplifier between the Sonos and the Russound power amp?

According to Sonos, the Connect has a built in DAC and I can plug it directly into the amp.

With Decent RCA interconnects and a good DAC , no need to spend a fortune now , results are invariably better than most recievers.

Can you recommend some DACs if I wanted to look into them? Also, good RCA cables are going to run on average around $75? I see people bidding $999 on an RCA cable. Is there really such a difference?

 

[dante01]

Thanks for the information guys. Definitely clears some things up.



According to Sonos, the Connect has a built in DAC and I can plug it directly into the amp.



Can you recommend some DACs if I wanted to look into them? Also, good RCA cables are going to run on average around $75? I see people bidding $999 on an RCA cable. Is there really such a difference?

A pre amp has nothing to do with DACs. A pre amp is where you'd adjust volume or select which inputs to output to a power amp. Is the Sonos's line level RCA output variable and does the Sonos have the ability to control this in terms of volume?

You do not have to spend anything near $75 for a reasonable pair of RCA leads. The amount you spend is very dependant on the cost of the hardware they are to be used in conjunction with. I doubt you'd be able to distinguish any difference between cables costing less than $20 and cables costing in excess of $100.

Look at the Arcam rDAC.

 

[TangledUp]

A pre amp has nothing to do with DACs. A pre amp is where you'd adjust volume or select which inputs to output to a power amp. Is the Sonos's line level RCA output variable and does the Sonos have the ability to control this in terms of volume?.

I hope I am answering this correctly. On the sonos you can adjust the volume directly from the device. So I assume that means the RCA outputs are variable.

 

[dante01]

I hope I am answering this correctly. On the sonos you can adjust the volume directly from the device. So I assume that means the RCA outputs are variable.

Without being able to test this, yes if this is the case, you should be able to connect the Sonus directly to a power amp, without a pre amp and then control the volume via the Sonos.

 

[TangledUp]

OK thanks alot.