Dale how nice to see you're here too, yeah i sat for hours testing amps and finally found the most neutral sounding under SGD300 imo the Ordnance .25, my other amp the X02 is colored but thats for hungry cans. I prefer to listen to my DT48 and DT48A direct without another amp, but to add the external DAC Ordnance.25 is still great and doesn't add much.
A little more expensive neutral Amp can be the AHA 120 from Just Audio.
IMO the Sansa is a bit soft, just put the internal gain on all the EQ settings, your A-Jays don't need much extra boost from an amp, they are sensitive enough for high volume listening.