The extra gain is 26 dB which is sufficient to convert a mm phono input into mc suitable for the lowest output mc cartridges. I've used mine with medium-priced mc cartridges - AudioTechnica AF5 and Ortofon MC10 - with no adverse effects. I've been able to compare them with the dedicated mc input on a medium-priced preamp. The latter was slightly more refined, but in no way was the input via the T5 transformers objectionable or compromised.
The situation with high-end cartridges and amps may be different. Make sure that your cartridge is optimised for a 3-100 ohm input impedance.
