I'm looking to sell a piece of equipment (valhalla 2) that I just do not use and I am getting offers to trade for older DACs - either a California audio labs sigma II 16/44 or a Theta dspro progeny. The press on these from when they were new is pretty interesting, but I'm thinking that the technology in them has only been improved, and at much lower price points. Is that correct thinking? My current DACs are a Schitt Modi 2 and a Starting Point Systems DAC 3 (this is from ebay - TDA1543 + Reclocker). My audio systems are: hifiberry optical out to the above-mentioned DAC3,then Adcom GFP-750 pre-amp, GFA 535 amp, and ADS L810 speakers. Does anyone have any input about the suitability/benefit of either of these old DACs in my system? (The modi2 is in a stack with magni2 going to JBL LSR305 speakers. Source on that is Squeezebox touch optical out.) Thanks for any advice you can give!