I purchased a used 50 Caliber + back in March and it had 3 standard JJ ECC83 preamp tubes, a JJ ECC81 in the fourth position and an Electro Harmonix 12AX7 in V2. The power tubes were Ruby 6L6GC's.
Although the amp sounded good, it was a little "buzzy" sounding and I kept the gain low, to keep...