[Sam21]

other than the older modi and the HifimeDIY DACS, can you name a few SPDIF only DACs ?
 
EDIT: It must have a pre amp line out.

 

[PurpleAngel]

I have no idea what the difference is between a regular line-output and a pre-amp line-output, to me they seem the same.
 
Optical DACs I know of
FiiO D03K and D07K
SMSL SD-192 Pro
 
If you do a search on eBay for "optical DAC", there are over 200 different sellers offer dozens of different models of optical DACs.

 

[Sam21]

  I have no idea what the difference is between a regular line-output and a pre-amp line-output, to me they seem the same.
 
Optical DACs I know of
FiiO D03K and D07K
SMSL SD-192 Pro
 
If you do a search on eBay for "optical DAC", there are over 200 different sellers offer dozens of different models of optical DACs.

thank you purple angel, I am concerned because double amping adds distortion to the signal, if the signal goes out through the pre-amps it bypasses the amp section.