Thiel Owners

In a previous post, I described the 2008 COAX terminal connection backwards (not important).

I just got off 2 email threads. 

1) The Audio Engineer in Canada, Mitch Barnett, looked at the new graph I sent him and said we know for sure it is now the COAX drivers that have a problem. 

2) John Siau from Benchmark looked over the specs of the Thiel CS3.7 and said the amp will work in mono. That is the mono amp will not damage the speaker. I should take the 30 day home trial and see if it actually improves the sound.

3) I will get in touch with Rob and pick his mind on what could be the cause of the COAX issue.

Yea it is integrated and only has rca. I’m not too concerned about xlr connections. It’s a beefy unit. I’m getting it to replace the luxman l-450 that i was using as a pre amp even though it’s not meant to be used as one (doesn’t have pre out)

@yyzsantabarbara , If an amp can't double down into lower impedances, at higher volume levels it can lead to frequency linearity issues. The Thiel's tend to have fairly steady impedance loads, so it might be less of an issue. FWIW, considering everything I'm not sure why you have such loyalty for the Benchmark. Something like the above mentioned Krell FPB 300 would be ideal. The FPB 300 has perhaps a bit of overkill power for your current room, but that's not a bad thing, especially if your considering moving your speakers to a larger room in the future. The FPB 300 is something of a sweet spot model in the line up, a nice step up from the smaller models, due to improved parts such as a bigger tranny. It's sensitivity also makes it a suitable model for direct connection for some of the newer high bit, high output DACS without having to worry about bit stripping, negating the need and expense of a line stage if you don't have analog sources to contend with. The issue with the Krells, perhaps due to their, though modulated, Class A output is that they seem to need recapping more frequently than some of the competition. That's not an inexpensive proposition unto itself and then there's the expense of shipping such heavy gear. Though I think you can conservatively expect 20 years between such servicing.

@thoft, the original Krell FPB's ("Full Power Balanced") are designed to work best through their balanced inputs, though if you wanted to direct connect to a high bit, high output DAC the RCA inputs might have an advantage to avoid bit stripping. The latter FPBC's and FPBCX's don't even have RCA  inputs; only XLR and CAST.
As far as using an intergraded as a pre, well I suggest using the KISS approach. Your just introducing more potential noise and failure prone parts.

I think focusing on doubling is somewhat misguided.  If an amp is stable and low distortion into 2 ohms it should be fine.  How much power can it put into 2 ohms?  An amp that can put 300w/ch into 2 ohms can put 150 into 4 ohms and 75 into 8.  Whatever it can put into 2 ohms is what matters rather than doubling.

With the 3.7s it's hard for me to imagine they need a huge amp.  They're 90db sensitive.  (Stereophile measured 90.7.)  2 watts for 93db, 4 for 96, 8 for 99, 16 for 102, 32 for 105, 64 for 108, 128 for 111, 256 for 114.  I'd be shocked if these can get anywhere close to 114db before exceeding their physical limits.  The fairly inexpensive amps I have do the first 30 watts in class A.  I'd bet that pretty much all of my listening is in class A.  I worry about bottoming out the drivers a lot more than the amps.