These evening I went to finally try the KR T100 in the LIO DHT PRE, and.... and....
they don't even fit because their base is too large for the top panel opening!
These T100s are quite larger than the 300B, PX4, SV811 tubes. Their base has a approx. 1.85" diameter
and they are 7 inches tall (not including the pins). So even though they have the same UX-4 pin-out,
they are big boys. The glass diameter is 2.3 inches.
I did briefly remove the LIO top panel and plugged them and confirmed that they do seem to work
fine with LIO DHT PRE circuit, but I did not get into doing comparisons between them and the KR PX4 - which
we all know fits fine and sounds lovely.
When I first received my KR T100s (before RMAF, when I was finalizing the L2 Signature Preamp design and getting
it into production), they fit into the L2 without any issues because the opening on the top is 2.5" diameter as it was designed
to have about 1/3 - 1/2 of the tube coming out from the inside the unit. So being as busy as I was, it didn't even cross
my mind that the T100's larger bass would not fit into the LIO top panel opening.
Well, the Elrog 300Bs that are coming next week should fit fine in LIO and we'll see how they sound!