Converter for digital out to analog in to Integrated

My wife purchased a smart TV that bypasses the mac mini I use as a music server and to watch Netflix amazon prime etc. (the picture quality is better than the mini FWIW).  My cheap solution was to purchase a $15 Prozor digital to analog converter and run the SPDIF thru it and RCA out to my Luxman integrated.  It doesn't sound terrible but the gain is very low (either from the TV or the converter???) and I have to turn the amp up three times as loud as normal to hear it at desired volume.  I unhooked it and put it back in the box. 

Any ideas?  This Prozor has 7,000 great reviews but you know how that goes.  Samsung TV.  I adjusted the TV so it was PCM out otherwise I couldn't get any sound.