Ive had Cary 805's for many years.You didn't specify B or C series. It makes a difference because the amps sound much better with NOS Output tubes. In the C series you use an 845 output. The problem with is that the 845 NOS tube for that application is the RCA 845 and they go for $800-1300 /pr on the used market. Too prohibitive for someone with ProAc 2.5's and Ive only seen two sales in last ten years. The Series B on the other hand uses 211 outputs. NOS GE 211's can be readily had for about $200-250/pr. The 805B with NOS outputs is far superior to the Series C with the stock 845 (Which I think are Chinese). As a bonus, the 805B is cheaper used ($3800-4000) than the 805C used ($6000). On the ProAc's: yes they are a nice match: very rich, large liquid soundstage, somewhat rolled. (The NOS GE 211 - or RCA 211 that I use - helps dynamics considerably,extends energy into the top end & tightens bass, without losing the "magic" of the amps, which is the art of the matter). You will like the combo, but the right cables will make a difference here. Since the combo excells at mids and space, a cable that can translate this is important. NBS & Purist are no-brainers here. Expensive, but something to consider down the road. On 98 pre: No, it is euphonic and will make the system too remote, slow and creamy. If you want to stay with richness but without the blurring, go to a Joule Electra LA-100 MkIII ($1700-1900 used). If need more delineated but still exceedingly liquid, then no brainer: Supratek Syhra. Unknown right now but not for long. Imported from Australia & gorgeous. They have a website. If want to stay with known component, then CJ 16LS - but it will still cost you. Last things: make stands for 805's, replace rubber feet with good cone types (Walker best, but Black Diamond #3 ok), NOS Brimar inputs best (yes, better than RCA...), and WE 300B's critical for driver tube (if go for 805B, get one with WE's because stock tube was Cetron and they were horrible. Sovtek 300B, a common replacement, is vibrant w/ good pace but a little lacking in finesse, especially when amps pushed). Also, Custom power cord #11 great value ($150 used) Good luck.
