I'm been using a Cary PH302 for about 7yrs and like you I found external SUT's into the MM stage to work better with the cartridges I used (lower output MC's).
I've tried Bob Sattin's 3440A, Hashimoto HM7 and Lundahl 1941. The first two were 1:15/1:30 (from memory) and latter is pretty similar 1:16/1:32.
I agree that a healthy input voltage to the Cary MM stage sounds more dynamic.
I never had any overload problems running a 0.4mV ART9 mc into the 1:32 setting which will boost that cartridge to 12.8mV.
However I found the ART9 to work better with 1:16 (6.4mV) and reflected loading of 184ohms.
You're talking about 1:20 which will boost 1mV to 20mV. I would think a 1:10 SUT would be more appropriate - but I don't know what the overload specs are for the Cary.
Assuming no overload issues, 1:20 SUT (26dB) will give 64dB total gain with the Cary MM (38dB) which may be excessive for your setup - but that will very much depend on the rest of the chain.
IMO 1:20 would be more appropriate with lower output mc's, say 0.3 -0.5mV range. But of course much depends on the individual cartridge and system specs.
I've tried Bob Sattin's 3440A, Hashimoto HM7 and Lundahl 1941. The first two were 1:15/1:30 (from memory) and latter is pretty similar 1:16/1:32.
I agree that a healthy input voltage to the Cary MM stage sounds more dynamic.
I never had any overload problems running a 0.4mV ART9 mc into the 1:32 setting which will boost that cartridge to 12.8mV.
However I found the ART9 to work better with 1:16 (6.4mV) and reflected loading of 184ohms.
You're talking about 1:20 which will boost 1mV to 20mV. I would think a 1:10 SUT would be more appropriate - but I don't know what the overload specs are for the Cary.
Assuming no overload issues, 1:20 SUT (26dB) will give 64dB total gain with the Cary MM (38dB) which may be excessive for your setup - but that will very much depend on the rest of the chain.
IMO 1:20 would be more appropriate with lower output mc's, say 0.3 -0.5mV range. But of course much depends on the individual cartridge and system specs.