Best significant upgrade? Dac? Preamp?


Hi guys!

Im hoping some of you with knowledge of my system can help me make a good decision about my next upgrade.
I would like a surprising and obvious difference not hard to spot subtle change.
From my research i think the next move should be the Dac.
I would like to explore DSD,i have some SACDs now.
my system:
Mark Levinson 320s preamp
(Would i see a difference with a ML no.52?) I am also looking at the no.52 ,would i see a big difference compared to the 320s? Worth the extra $$ ?
interconnects: Acoustic Research master series silver high definition RG6
ML 431 amp
XLR: +bo ? +ba ? Only info on them

Wilson Audio Watt Puppy 5.1 speakers (serie 7 tweeters) +transparent music wave plus cables
Arcam rdac (wifi) with Teddy Pardo power supply.
Running on mac air (usb) ,Tidal HIFI
(i currently listen most of the time to this vs rarely SACD).
Thanks!



128x128nicsaudio
 The previous incarnation of the PS audio top-of-the-line DAC doesn't do DSD, but it is an amazing performer. And it is in your price range. I recommend looking at the perfect wave DAC Mark two, wIth bridge Mark two if you can find it. If not you can always  upgrade the bridge directly through PS audio.   Best of all, with this type of investment which is already greatly depreciated, you can sell it for nearly what you paid for it if you decide to move on. The other option for you in the future is to upgrade this unit for the newer DSD model by replacing the internals which are available  from PS audio. 
I would say room treatment. 50% of the sound is room acoustics. GIK polyfusors are very effective at absorbing some bass and also diffusing mids and highs. 4 of those in a room can do wonders.
I second the motion to spend money on room acoustics before spending more on equipment. It is 50% of SQ. You can find used ASC tube traps from time to time on eBay, or try locally. I treated my room and it was a significant upgrade. Now that my room is fixed, I am able to evaluate more accurately the effects of equipment upgrades.
Dac first for sure. So many good designs now and changing fast. Really like the moon products and much better output stage than the ps audio dac. With the mind option you can stream tidal etc. Very nice dacs from meridian as well. At your price point you may want to look at on-line companies which are making some excellent dacs-myteck (sp?) etc.
Can't argue w/ (carefully chosen and especially bass-trap type) room treatments, but I also agree that the right Dac can make a bigger improvement than you might expect.  For me, upgrading to a Schiit Gungnir Multibit (upgrading from a Stereophile A+ rated dac, by the way) made a surprising improvement in terms of overall listening enjoyment, and is arguably the new MVP in a system where some individual components are 5x its cost.  No DSD on this one though. It is warm enough that I would suggest trying it first before adding tubes to the system.  

Also upgrading a usb source from an (albeit older) mac mini to an Auralic Aries mini provided a surprising improvement and high ROI IMO.