change amps or speakers

The Gold Stratus won’t do. Low sensitivity and 4 ohm nominal which drops below in the midbass requires power and high current.
https://www.stereophile.com/content/psb-stratus-gold-loudspeaker-1997-measurements

You have some wonderful monoblocks, they deserve a better speaker than the PSB. I owned PSB Synchrony and wouldn't pair this 4 ohm speaker with a tube amp. It takes power to drive the bass.

@majorc
I’d get a good matching tube preamp no matter what. Tons of threads on this topic alone. If you do order a Linestage preamp from Mike at QS, heads up, for $50 upgrade service fee, he can convert the TapeOut to a 2nd set of PreOuts if yourdecide to bi-amp as others suggested earlier. Or, use the added pre-outs to add a really good subwoofer for added bottom end your mono 60s won’t have to make up for. A nice sub could fill in bottom end and let your LFT8s flow with KT88s in the Mono 60s. Add good tubes in Linestage preamp from Mike@QS.

Local Tech Option: 
You mentioned a local tech. Yes, a good local tech can also upgrade coupling caps in those amps to much better ones to add transparency you are looking for, along with checking tubes, re-bias. I upgraded my own QS Mono 120s with Mundorf Supreme EVO Silver-Gold caps, and the upgrade has been very rewarding. Yes, see your tech! 

Option-C:
Check this out. If you keep the LFT8 speakers, you could do the preamp now, add KT88s, run for 1-2 years. Then,wait for KT170 based amps to come out next! Yes, did not mis-spell. New tube coming from Tung Sol would be perfect for your LFT8s. :) Guarantee you’d love those LFT8s all over again with a bit more drive.
https://www.instagram.com/p/CG77jvZJEoH/?igshid=xj8re0i2fhl2

Asking again , are you making rated power with the DAC direct ?

A pair of Vandersteen Quattro are magic with Quicksilver amps, the original cloth versions are dropping into $3k range. I have heard 60 watt QS driving 5a, sublime...