I'm running a Soundsmith cartridge into a Hafler IRIS preamp.
Because it's a moving iron design it has a lower output than most MM cartridges.
It sounds great, and the IRIS's internal phono stage is pretty good, but I'd love to get a few more db of gain out of the phono stage.
Looking at the schematic, the only difference I can tell between MM mode and MC mode is the insertion of a 100 ohm load resistor, the removal of the 220 pF load capacitor. As well as the bypassing of a 316 ohm resistor in MC mode.
I've included the schematic of the phono stage portion of the preamp, and I've edited it into what I believe is the circuit diagram because the original schematic on the inter webs is pretty low contrast.
Is it correct that this 316 ohm resistor regulates the gain of the phono stage? The preamp bypasses it when you press the switch on the back panel from MM mode to MC mode (along with the aforementioned load resistor and capacitor), so would modifying this resistor to a lower value increase the gain of the cuicuit?
Because it's a moving iron design it has a lower output than most MM cartridges.
It sounds great, and the IRIS's internal phono stage is pretty good, but I'd love to get a few more db of gain out of the phono stage.
Looking at the schematic, the only difference I can tell between MM mode and MC mode is the insertion of a 100 ohm load resistor, the removal of the 220 pF load capacitor. As well as the bypassing of a 316 ohm resistor in MC mode.
I've included the schematic of the phono stage portion of the preamp, and I've edited it into what I believe is the circuit diagram because the original schematic on the inter webs is pretty low contrast.
Is it correct that this 316 ohm resistor regulates the gain of the phono stage? The preamp bypasses it when you press the switch on the back panel from MM mode to MC mode (along with the aforementioned load resistor and capacitor), so would modifying this resistor to a lower value increase the gain of the cuicuit?
