Graduating to separates need help


Graduating to separates need help
I currently have a Marantz SR 18 receiver  that was feeding and Adcom GFA 555 that has been modified. my SR 18 had a memory issue and the local shop messed up the micro processor and I can’t set my speakers to large now in the menu
I also have a Denon AVR 5600 receiver which I’m using now and there is no comparison in the sound the Marantz destroys the Denon

I don’t know enough about preamplifiers to buy a good used one I need something with good DAC  
the DAC chips in the Marantz sounded phenomenal. should I just buy another SR 18 and feed it to a better amplifier or should I jump to a parasound preamp P6 and buy a better amplifier I was looking at some Bryston amplifiers which I really like but my budget is not big I want to keep my budget around 2000.  I don’t mind used.  I just want better sound than the sr18 adcom setup.  Any suggestions 
rab0829
DACs look good but only pass 96/24 on toslink input?

Why in the world would you even use the toslink input?  Just use SPDIF. 

I would suggest looking at the Peachtree Nova 300 or one of the similar offerings from Marantz, Yamaha, Rogue Audio, etc. You should be able to find a nice integrated within your budget that will sound much better than your 17 year old Marantz. I mention the Peachtree because it has a very good DAC and home theater bypass. 
So many of these suggestions seem that they might hit home for you...

I’ve heard nothing but great things about the Adcom amps in a modded config. Some prefer to completely start from scratch, personally I’m into the additive/change a bit at a time philosophy. 

I’ve got a Schiit Uber 2 that sounds great. Can only imagine what the Multibit here on Agon would sound like! Pair that with a Saga or Freya and keep your Killin Adcom, good cables. I’ve considered that exact configuration for myself. The good thing about those preamps, they can opperate in active/passive/buffered modes so they’re flexible (not sure if they both go that far, but at least Teo out of three for the saga I think). You can tailor your sound depending on the recordings. 

Couldn’t go wrong with that?

Yep, I don’t know. I might buy that Multibit for myself! Jk ;)


.....Foegotcto mention that I’m not sure about the impedance  matching for that? Someone here more knowledgeable could answer to that.
No comments on the Denon AVR-5805 with 32 burr Brown DACs   And Audyssey     32 bit processors 
I keep reading on forums that in its price range there are no pre pro combos that can compete.   
I can still use my adcom.  
Or use extra money to upgrade to a better amp.   Adcom sounds ok to me more powerful but the old marantz sr18 amp sounded warmer.   And the denon avr5600 is actually pretty strong but the preamp section of the old denon is grainy harsh and lacks detail