Hello!
>Am I missing something here? Please put me straight.
It's not my usual way to 'put you straight' but I think the missing link is that the impedances in any source are nothing like 1M. That high an impedance would never show up in a source as it would have issues with any type of pre-amp and also with even modest (short) lengths of cable.
I have 2 tubed phono stages here and have experience with others as well. The two I have here are the K&K kit and the Haggerman Trumpet. Both really good stages from great tube audio circuit designers - I'd say about as good as anything out there. The Trumpet is listed as 750 ohms output impedance and the K&K (from memory) is a similar output impedance. Both work extremely well with the tx102 - no issues at all. I have also used a tx102 on an 834P tubed phono stage with good results but don't know the specs on that one. Myself and many others have used Audio Note Tubed DAC's. They are a really good match for the tx102 - and have a highish output impedance - at the upper end of what you'd find in most any commercially availiable sources. I could go on - I guess I already did.......
I have heard mention of some vintage tube stages with impedances of something like 10K but have not had the chance to try any. I think that would be above the limit of what any passive device would be happy with and even in an active environment carefull attention to cable lengths and other issues would come into play.
I hope this helps clear it up a bit.
Many Thanks!
John Chapman
www.bentaudio.com