Pioneer PD-F705, Tweaks?

[prickears]

I am an absolute noob to this side of sound reproduction.

I have a Pioneer PD-F705 25+1 disc (pulseflow DAC) and a PD-F407 25 disc (1 bit, Direct linear conversion??).

I love these machines just because i'm too lazy to change discs manually all the time, and they really are bomb proof, but I think I could do better SQ wise. The main problem ATM is the topend is heaps 'grainee' and the overall sound a touch 'ringee', ......sorry best description I can give.

I am running an active three way system, and currently use the 705 as the player. I am quite willing to sacrifice the 407 in pursuit of happiness.

Can I make one Better CD player using the parts from both (ie, power supplies, DACs, The 705, has optical out, 407 doesn't) and other general Mods to have a nicer sound?

Any advice, links, or other help greatly appreciated,

Thanx,

Mick.

[prickears]

A photo of each of the main boards, first is the 407, The power supplies seem to be part and parcel(?).