But 7 years ago the SP12 got a big brother, the SP14, and in the past 5 years or so the SP12 has almost been forgotten by buyers, as buyers were
no longer looking for a "budget" tube preamp, but the very best tube preamp kit available, the SP14. Maybe 100 SP12s were sold in 4-5 years.
During the past 4-5 years well over 400 SP14s have been sold, more than 4x as many.
But let's NOT forget the SP12. The SP12 uses the EXACT same circuit design as the SP14. But it uses the popular 12AU7 tube instead of the larger 6SN7 tube.
The SP12 has a single power power instead of dual power supplies. It only needs one power transformer. The SP12 kit is $250 less than an SP14.
ALSO, the SP12 is the ONLY VTA preamp that you can add an INTERNAL phono stage to. The older PH12 phono stage has been replaced by a much superior PH14 phono stage,
the PH14 can fit into the same chassis. The improved PH14 phono stage also has it's own power supply, and it has an output buffer.
The SP12 is definitely NOT a "budget" tube preamp, it's the smaller brother of the HI-END SP14, 3/4 the size and 3/4 the price, and when you add the PH14
phono stage you can have a COMPLETE tube preamp with integrated phono stage, for LESS money than the cost of the SP14 preamp.
Here's a link to a recent SP12 build . . . SP12 - 2019 build photos
Here's a link to a customer review (back in 2011) SP12 review