Mismatch - between SUT and MC cartridge.

Thanks Raul,

I have used Ortofon MC20 with Ortofon T20 SUT, and they match pretty good and the sound is wonderful. I also have an Ortofon MC100 which has similar output level with MC20, but requires a higher load impedance (>10ohm vs 2~4 ohm).
Even though I knew about the impedance mismatching I gave a try. I assumed that MC100 would be much better than MC20 or even MC30.
I have not done serious listening yet, but I generally felt satisfied. Threw out some jazz LPs (NOUVEAU BACH (LA4), Kind of Blue, Sinatras) and few chamber music and orchestral music LPs. Felt a bit more dynamic and detailed sound, but a bit congested sound at full orchestration or high volume. Maybe the signal from MC100 is too hot for the SUT?

My system is BAT VK60/VK30 with VKP3 phono, and Tyler Linbrook Signature Systems.

Most cartridges that have an extremely low source impedance, such as the 3-4 ohms you mentioned, are quite low in output (fewer coil turns mean low impedance and low output), and therefore also need more gain. The transformers that "match" to such cartridges typically have higher turn ratios and gain. But, if excessive gain is not a big issue, you can use such transformers with cartridges with a higher source impedance and the result should be fine.

I believe Art Dudley, in a series of articles in Stereophile about SUTs, said that, not withstanding supposed compatibility criteria, he has not heard problems with mismatches.

I have personally never experienced compatibility issues except for not having enough gain. Most SUT with enough gain have worked well, and personal favorites seem to remain favorites with a wide variety of cartridges.

Thanks for your response.
It is good to know that the voltage level matching is much more important than the impedance level matching.
I've listened to many more LPs in more serious manner, and I guess I would like it, even though I cannot say that MC100 (on my system) is much better than MC20.

Say your cartridge is 10 ohms and the SUT was designed to load a 2.5 ohm cartridge. This means that the low end bandwidth will be two octaves less due to the fixed inductance. Depending on the design choices and system matching this could be a good or a bad thing.

So if the SUT designer chose to put the -1dB point at 10hz for a 2.5 ohm cartridge, it will be -1dB @ 40hz if fed from a 10 ohm cartridge which might be an issue. If however the design were to be -1dB @ 3hz with the 2.5 ohm cartridge, the 10 ohm source will move the -1dB point to 12hz.

dave

Thanks.
I guess I need to spend more time to understand your explanation. Overall, it seems to work fine to my ears.