On the inside the Phono stage (2 tubes on the left) seems to be standard with ECC83 tubes giving 44dB lift.
The line stage, which the phono stage plays through, has changed from ECC83 (mu 100) to ECC82 (mu 19) to achieve the 0dB line output, the standard spec was 12dB for the line stage output giving 56dB total for the phono output.