You have a fundamental mismatch between cartridge and phono stage. The CAT SL1 has a MM phono stage. It lacks sufficient gain for even the "H" version of the Micro Ruby, which outputs less than 1/6th the voltage of an MM cartridge. The CAT also does not provide the loading the Benz wants to see.
Inadequate gain will make music sound thin, distant and lifeless. It also buries low level details beneath the system's noise floor. Any decent LP has more low level detail than a CD. You'll hear them once you solve this problem.
The loading of the CAT is much too high for the Benz, or any other MC cartridge. This will suck bass weight and "prescence" out of the music. You'll still hear bass, but no meat on the bones and images will be diffused.
Short of downgrading to a MM cartridge (not recommended) there are two ways you could address these issues. Properly implemented, either approach will solve them both.
Solution #1 is to change to an MC phono stage. Variable gain and loading would be nice, to avoid tying yourself to one particular cartridge forever. (Every MC cartridge has it's own gain and loading requirements.) You could do this with an outboard phono stage or by replacing the CAT altogether. This is not what I would do, though some would.
Solution #2 is to add stepup transformers between cartridge and pre. If you like the CAT then I'd recommend this approach. Take a look at the Mu trannies at www.bentaudio.com. Just $750 or so, and they include easily variable cartridge loading. This means they'll work with the Benz today and just about any conceivable MC cartridge tomorrow.
Fixing your gain/loading mismatch should pretty nearly maximize performance from that TT/arm/cart. They're not the last word but they should be able to outplay any CDP, even one as nice as the AA. Right now you're not hearing everything they can do.
Inadequate gain will make music sound thin, distant and lifeless. It also buries low level details beneath the system's noise floor. Any decent LP has more low level detail than a CD. You'll hear them once you solve this problem.
The loading of the CAT is much too high for the Benz, or any other MC cartridge. This will suck bass weight and "prescence" out of the music. You'll still hear bass, but no meat on the bones and images will be diffused.
Short of downgrading to a MM cartridge (not recommended) there are two ways you could address these issues. Properly implemented, either approach will solve them both.
Solution #1 is to change to an MC phono stage. Variable gain and loading would be nice, to avoid tying yourself to one particular cartridge forever. (Every MC cartridge has it's own gain and loading requirements.) You could do this with an outboard phono stage or by replacing the CAT altogether. This is not what I would do, though some would.
Solution #2 is to add stepup transformers between cartridge and pre. If you like the CAT then I'd recommend this approach. Take a look at the Mu trannies at www.bentaudio.com. Just $750 or so, and they include easily variable cartridge loading. This means they'll work with the Benz today and just about any conceivable MC cartridge tomorrow.
Fixing your gain/loading mismatch should pretty nearly maximize performance from that TT/arm/cart. They're not the last word but they should be able to outplay any CDP, even one as nice as the AA. Right now you're not hearing everything they can do.