Upgrade path

I know the LS3 well; great SS preamp of the day but being a former Dunlavy owner I wouldn't use the LS3. Seems you like the Theta amp so I'd throw out look into a tube preamp. Many great tube preamps out there and if $4K is your budget you'll have no problem finding a nice one.

I think I'd do the preamp if the Dunlavys are staying.

Not opposed to replacing the Dunlavys. But most say I'd have to spend more than 4K to do better? I like the detail I get from the Theta just wish I had a little more bottom end. Again most say to get better bottom end I would lose some of the midrange unless I get into super high end amps. So there is my delima. Can I upgrade my speakers or amp using 4K as a budget or at this budget is my only option upgrading my preamp. I was looking at an older Mac amp the MC2500?

Too many variables to consider before throwing out what amp may give you a little more slam. Used to work at the local Dunlavy shop part time back in the days. The SC4s are ruler flat so if your looking for a big fat bottom you may never get there. Your room size has as much or more to with it. We also sold the ARC LS3 and that was a really good preamp but there’s much better today. I’d look at my speaker placement, do you have dedicated circuits to your equipment which your amp really needs to get the most out of it, and lastly if you don’t have revealing cables that can deliver the goods then I’d start there with dedicated lines. The SC4s are big heavy boxes to move around so wondering if you have the spikes in the plinths?