You all are making this appear much too complicated. I've plugged my TVC into a few friends systems and always had impressive and consistent results. I've changed amps and sources. I currently have a far from ideal load with long IC's, a 10K Zin hi-pass and parallel low-pass/bass amp. A mismatch seems to be the exception I haven't run across and I've seen some unexpected active component or amp/speaker mismatches.
I have played with a couple DIY attenuators but not as a system volume control. One was for a biamp system to control gain and the other replaced a pot in an active preamp. Probably dissuaded by the negative reviews. The TVC was a fairly cheap experiment that I didn't expect to work and, if I had believed some of the "experts", shouldn't work. There's a story but I would rather not mention names. It was a DIY project and it even worked well when I had it wired wrong. That's another story, not for A'gon.
Many of the RVC/attenuators have had a fairly low 10K Zin but, recently, there are more options for higher impedance up to 100K.
I have played with a couple DIY attenuators but not as a system volume control. One was for a biamp system to control gain and the other replaced a pot in an active preamp. Probably dissuaded by the negative reviews. The TVC was a fairly cheap experiment that I didn't expect to work and, if I had believed some of the "experts", shouldn't work. There's a story but I would rather not mention names. It was a DIY project and it even worked well when I had it wired wrong. That's another story, not for A'gon.
Many of the RVC/attenuators have had a fairly low 10K Zin but, recently, there are more options for higher impedance up to 100K.