Thiel Owners

I have an interesting observation from using my CODA #8 amp on 3 sets of speakers including the Thiel CS3.7. Now my following observation are not based on perfectly matched volume levels, but I think I got a good approximation.

My CODA #8 has power meters that tell how much current is being drawn. On my Thiel CS3.7 most of my office listening did not move the needle on the meters. I had to turn up the volume to a level that was inappropriate for the office to see the meters move.

With my RAAL SR1a headphones connected to the CODA #8 via the amp interface box the needle dances at lower volume levels. I could accept that since the amp interface box is inefficient.

I was surprised to see that my KEF LS50’s also cause similar movement of the needle as the RAAL SR1a. This was really surprising. I use the CODA #8 on this system.

I would have expected the Thiel CS3.7 to make the needle dance the most. I do notice sonically when I use an underpowered amp with the CS3.7.

The CODA #8 is a very good amp on the CS3.7. I now use a KRELL 175XD on the CS3.7. This amp is not ideally suited for the CS3.7 but my room is small, and the sound is excellent.

The RAAL SR1a is now driven by a Benchmark AHB2 + Schitt Freya+ tube preamp. I love this combo. I found the AHB2 underpowered for the CS3.7 though I loved the sound on some music.

^While not specifically calling out the Coda, I often suggest caution when reading the meters on consumer gear. Despite their not inconsiderable expense, they are almost never calibrated, and more often than not serve to misinform rather than to inform. I'll hazard a guess that the digital meters on some of the newer ultra-expensive gear might be more accurate.

@unsound My meters observation is said in a relative sense. The CS3.7 seems to draw relative less current than the other 2 based on the movement of the meters. It is a rather stark observation because at about the same volume level the CS3.7 does not move the meters and the other 2 do. 

If I was using digital meters I may have exact number to state but the general pattern that I am describing would be the same.

I think that makes sense. The Thiel sensitivity is about 6dB higher than the Kef (90.7dB vs 84.5dB according to Stereophile’s meansurement).

@yyzsantabarbara , I think the first graph on each of the respective links might explain what's going on:

KEF LS50 Anniversary Model loudspeaker Measurements | Stereophile.com

Thiel CS3.7 loudspeaker Measurements | Stereophile.com

Jim Thiel seemed to be rather cognizant of the effects of a steady vs. a variable impedance load on amplifiers. As much as a low impedance is tough on amps, amps don't typically care for a varying load, especially tube amps. A variable load can exacerbate the mechanical / damping issues of analog meters as well.

@Imhififan, at these impedance loads the rated sensitivities can be misleading.