Thoress Phono Enhancer

From the website:
These exceptional tube phono enhancers allow on-the-fly selection of the entire range of phono equalization curves used by the prominent record labels throughout history.
In addition, we have implemented subtle tone control facilities to compensate for sound degrading artifacts
which may have been introduced during the recording
or cutting process of a given record. The Enhancer’s
unique tone control circuitry shapes the playback deemphasis curve itself, within wide limits, without
the use of any clumsy conventional tone control circuitry. Bass, mid-bass and treble are independently variable by means of rotary knobs.
The Enhancer will allow you to hear much more deeply
into the grooves of any kind of record than a common
phono preamplifier restricted to RIAA deemphasis,
and optimum tonal balance and “good sound” may be
restored even to poorly mastered or manufactured discs.
It is well known that tone control is especially beneficial with the reproduction of early monophonic records. Interestingly, most (early) stereophonic records and even poorly produced modern records will benefit considerably from these features too. A more detailed description of the tone control facilities can be found in the manual. Tone control of the kind used in our Enhancers proves to have a much stronger impact in restoring a satisfactory overall tonal balance than simple adjustment of the phono deemphasis curve in accordance with the origin and vintage of the record.
The loading resistors for this phono stage are very easy to access. They are soldered across the input RCA's. This enhancer has had the stock resistors changed to Vishay Nudes, which greatly improved the sonics. The values are 4 MC inputs loaded to 510 ohms, one MC input at 135 ohms and 1MM input at 47k ohms. Again, these can be changed to suit your cartridge very easily.