I have been using the Cambridge 851 CD player for a few years and want more.

I use an 851C as well and was pleasantly surprised how much it improved with the Synergistic Black fuses; there are two. I also run a Nordost Vishnu PC which really brought out how good this player is. No doubt a DAC could improve things, but I’d still recommend changing out the fuses first and if you’re using the stock PC change that out too before you spend money on a DAC. I also use Ayre mrytle blocks which also elevated the 851 sonically. Point is the 851 is a fine player that has more potential than in its stock form. 

To donpepe

fuses are
2.5A 250V small / Fast 5x20mm
2.5A 250V small / Slow 5x20mm

I don’t recall which one went were without opening the lid but I think the slow blow was back on the power supply near the IEC power cord socket/back right corner and the fast blow on the S3 Servo board left of transport. You’ll know when you look at the stock fuses as the slow blow has the fatter wire.

The stock fuses are actually 2A but everyone recommends going just a little larger value so I did. I first installed the Synergestic Reds which sounded better than the stock fuses. Sound was warmer but I felt they didn’t open things up as much as the Black I installed on my Modwright preamp so Chris at VH Audio let me exchange the Reds for Blacks and this was a bigger improvement as it really opened things up. The Blacks are faster and very relaxed... sounds much closer to my Table now. Now that the Blues are out I’d spend the extra and go for those. Chris gives you thirty days to try them out so not much to lose except your time and shipping.

Hope this helps.