I would definitely avoid the use of a SUT with most or all Grado cartridges, as well as avoiding the use of most phono stages which utilize a SUT internally as their input stage for low output cartridges.
If a SUT is used the load impedance seen by the cartridge will be the load impedance that is applied to the output of the transformer by the phono stage (typically 47K) divided by the square of the transformer’s voltage step-up ratio. Typically a 0.5 mv cartridge would be used in conjunction with a voltage step-up of approximately 10x, which would mean that the cartridge would see a load impedance of 470 ohms. Way too low, at least for results that are anywhere close to being optimal.
So if you choose to go with a separate phono stage you would want to choose one having a solid state or tube input stage, providing in the rough vicinity of 60 db or so of gain assuming the gains and sensitivities of the rest of the components in your system are not unusually high or low.
The lower gain version of the highly regarded Herron VTPH-2 ($3650 new) would be a great choice IMO/IME.
Regards,
-- Al
If a SUT is used the load impedance seen by the cartridge will be the load impedance that is applied to the output of the transformer by the phono stage (typically 47K) divided by the square of the transformer’s voltage step-up ratio. Typically a 0.5 mv cartridge would be used in conjunction with a voltage step-up of approximately 10x, which would mean that the cartridge would see a load impedance of 470 ohms. Way too low, at least for results that are anywhere close to being optimal.
So if you choose to go with a separate phono stage you would want to choose one having a solid state or tube input stage, providing in the rough vicinity of 60 db or so of gain assuming the gains and sensitivities of the rest of the components in your system are not unusually high or low.
The lower gain version of the highly regarded Herron VTPH-2 ($3650 new) would be a great choice IMO/IME.
Regards,
-- Al