I agree the E188CC is a great alternative to the CCa. I also quite liked the
Siemens ECC88, which is theoretically at the bottom rung of the family of
tubes,
but I liked the slightly warmer tonality of the midrange.
Either the Siemens E188CC or the ECC88 are great alternatives, and they and
be
found at prices substantially lower than the CCa. They just don't produce the
hyper real image size of the CCa.
However, I still prefer Amperex 6922 PQ USA White label to either of
these...since I prefer the Amperex house sound overall.
IMO, FWIW, Kumbaya...