Should I buy used Thiel CS5

I think that's a bit of an exaggeration made mostly by Stereophile.

A 87db 150w is fine (even 100w) , what Stereophile means is you need good current to back up that 150w  so it can do up to 300w into 4ohm and try to get near to 600w into 2ohms. (If you want the best from them)

" it can be seen that the CS5 presents an amplifier with a pretty severe load. To say the least—"current capability" if the sound is not to become anemic."
https://www.stereophile.com/images/archivesart/690CS5FIG01.jpg


Cheers George

@jeffvegas, Yes, a Krell FPB 400CX will work. Should work very well.

The CS5 is certainly one of the better Thiels ever, especially regarding bass reproduction (sealed woofer) but, as others have noted, needs a lot of current to drive properly (and quality current is $$$). $3K seems pricey to me for a speaker that age. You will want to replace electrolytic caps.

If you like the Thiel house sound perhaps but you need to familiarize yourself with this sound before buying. One look at the crossover on this speaker could scare the hell out of any prospective buyer. The tweeter on these older Thiels some find very objectionable.

You will want to replace electrolytic caps.

No electrolytic caps, all plastics, last forever (well almost)

https://www.whatsbestforum.com/data/attachments/17/17403-3e3aa52a4bb8c32c4dab3b281e022f17.jpg

" The CS5 crossover is itself also heroic. Constructed on a single hard-wired board, it incorporates 87 elements realized with 114 components. Only—only—55 elements are directly related to the first-order high- and low-pass filter functions, the rest being used to fine-tune the system’s time response. The two midrange units, for example, are electrically "moved backward," by the equivalents of ¾" and 3/8" respectively, to bring their acoustic centers into the correct alignment.
All coils apart from one are air-cored, and the capacitors are polypropylene and pure polystyrene types, the latter custom-made with tinfoil plates and copper lead-out wires. The internal wiring is a polypropylene-insulated solid-core type."

The tweeter on these older Thiels some find very objectionable.

I only found that with with bad recordings or soso electronics, same also goes for the CS7