Wow guys - I take a break and you all go at it! Unsound alludes to a "problem" in such a long, detailed thread as this one. Lots of information would be redundant for regulars, but helpful to new participants. I appreciate it when someone directs others to where they might access the discussion.
Regarding concrete repair - look for expansive grout at Lowes, etc.
Paradisecom - congratulations on your CS2s. In many ways that is the seminal Thiel design; it took the concepts generated in the model 3 and refined them for a smaller space and source material at a lower price. The CS2 sold more units than any other Thiel product ever - over 11,000 units. All the Renaissance work I am doing on the CS2.2 will be retrofittable to the CS2. Regarding black laminate - what a trip. I wanted to bring a polished lacquer piano black finish into an affordable form. It became sadly clear that was impossible. Material flaws, along with susceptibility to damage in production and/or shipping and use led to price increases and unhappy customers. It remained in the stable at an upcharge, but we never promoted it due to its difficulties.
Thoft - you have a problem. My 3.5s measure 4.8 ohms DC resistance which seems right for their performance impedance curve. Rob Gillum can help you troubleshoot. If it comes to replacing parts, consider the upgrades we’ve been talking about here.
Scubabird - Rob’s answer #3 invalidates part of my previous response about Thiel revisions. Sounds like 3.7 revision 2 was to recalibrate the changes made by migrating to PC boards. BTW: I agree with Rob on liking P to P on Masonite better than PC boards. Go to Rob for any problem - he has made and repaired every aspect of every Thiel product since 1988.
Regarding the Benchmark AHB2 amps. I would appreciate public discussion here driving Thiels. They are in my stable and your collective opinion would help me calibrate their performance compared with other high-performance amps, which I don’t have access to.
Papasmove - good score on Jim’s Krell FPB-600. I was your auction under-bidder - dropped out because I have no business owning that. FWIW, that amp was routinely upgraded. Dan D would send Jim the latest tweaks for his feedback. Rob G was prepared to spend up to $10K for it, but deferred to me who dropped out. Good score.
Back to the lab. I’m getting close to tri-amping, bi-amping, single amping comparison on the 2.2s.