ortofon T-5

I just found a pair of T-5's I had in my old box of parts and stuff. Are these mc step up transformers any good? How much gain do they provide?
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.
Thanks for the input.