Krell Reference 64

Big converter which, for a few years, was the "reference" indeed for many a serious audiophile, at a time regular d/a units started to use DSP programming to extract data from the shiny CD better than simple (or dual, or quadruple, or...) decoding chips.
In contrast with SACD / DSD, here was... the more complex the merrier.

So here are two Krell-configured series-operated Motorola DSP-56001 per channel operating at the unbelievable speed of 34MHz and outputting data to the two shielded D/A modules at 64x fs rate, for a total of 2.8 million 24bit words per second.
I don't know what is inside the d/a modules besides "Krell-programmed proprietary multi-bit trimming and associated circuitry"...

Three 50VA transformers, eight TO-3 Motorola power transistors (per channel !), multiple stage regulations, external clocking through AT&T terminals, 4-layer, mil-spec epoxy PCBs and linearity within 0,3dB down at minus 90dB.

Now that ICs are 24bit in resolution (and not only digital filters), now that 192Khz sampling rate is standard and now that Krell has (re-)discovered current transfer (CAST) like Sony did in 1982 (and others since)... is the Reference 64 still a reference in 2008 ?



Full-res images can be seen at Jay Torborg's.
A review at Stereophile's.
The owner's manual is also still available from Krell's own website.