[dhc0329]

I am currently running modded Zxr feeding the signal to NAD D3020 amplifier via optical. Have 2 Orb satellite speakers and Velodyne Impact Mini sub woofer. I was briefly using my Pioneer A/V receiver instead of NAD D3020 to make the connection and I was so pleased with the crisp sound and impactful bass. But now with NAD the sound seems to be so small and the clarity was definitely lost. Cheap treble and muddy bass now. Sounds so boxed in. 
 
I've looked for another amplifier with the higher power rating (NAD's at 30wpc) and found Denon HEOs (100wpc) but not sure if the bigger wpc alone will solve my problem. I checked few vendors but they don't seem to have the amp with all the connection I require. I need speakers out, optical in, subwoofer preout but it isn't easy to find the good amp with these 3 connectors. 
 
Any recommendation for high quality amp which will give me a boost? Again, I need these connectors. 

 

[PurpleAngel]

You might try using the SB-ZxR's DAC instead of the NAD 3020's DAC.
Run an RCA to RCA cable from the SB-ZxR's front speaker output (RCA) to the line-input (RCA) on the NAD 3020.
See if that improves anything
 
Instead of buying the Denon HEOS ($300?), you might get a better value getting a refurb Denon AVR-1513 A/V receiver, $119.
http://www.accessories4less.com/make-a-store/item/denavr1513/denon-avr-1513-5.1ch-home-theater-receiver-3d-ready/1.html
Run RCA to RCA from the SB-ZxR to the AVR-1513.
The 1513 comes with 75 watts per channel, plus it comes with a dedicated sub-woofer output.
I would assume having a dedicated sub-woofer output would help a little for audio quality, over what I'm assuming is your current connect using the SPEAKER LEVEL inputs and outputs.

 

[dhc0329]

Thanks for your advice. I've already tested the RCA. It sounded even more muffled than optical so I switched back. NAD does have its own dedicated 3.5 mm sub out  jack. Anyway, I got the Denon Heos tonight and tested the sound. I find the sound to be acceptable. Sounded more open and defined. But I am not sure if I can really use this device, as it seems, I need to have their mobile App to control the device. I cannot just connect the damn thing to my pc and play the music. I really don't care about this wireless over the cloud playing stuff. I will call Denon tomorrow to see if there is way to just hook this up and play without wireless connection and their mobile app.  
 
The reason I didn't want to keep using my Pioneer Receiver  was I want something compact on my desktop. Well, if I cannot have both way, I may just have to choose the sound quality over the size. I will consider your suggestion carefully as well.

 

[PurpleAngel]

  Thanks for your advice. I've already tested the RCA. It sounded even more muffled than optical so I switched back. NAD does have its own dedicated 3.5 mm sub out  jack. Anyway, I got the Denon Heos tonight and tested the sound. I find the sound to be acceptable. Sounded more open and defined. But I am not sure if I can really use this device, as it seems, I need to have their mobile App to control the device. I cannot just connect the damn thing to my pc and play the music. I really don't care about this wireless over the cloud playing stuff. I will call Denon tomorrow to see if there is way to just hook this up and play without wireless connection and their mobile app.  
 
The reason I didn't want to keep using my Pioneer Receiver  was I want something compact on my desktop. Well, if I cannot have both way, I may just have to choose the sound quality over the size. I will consider your suggestion carefully as well.

 
The picture I had of the back of the NAD 3020 did not display the sub-woofer output very clearly and it's not the normal "single RCA" looking jack.
Learned something new today.
 
Looks like those little Orbs sell for $250 for the pair, so I'm assuming they are decently good.
Good luck talking to Denon, hopefully they can help.