MC Step Up Transformer Choice

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Most of the time I use MC cartridge with 0.2mV output.

Also, the attachment is the circuit of the phono stage.

Can anyone tell me the resistor for RIAA in the circuit??
 

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We need the impedance declared on tech spec of the MC.
In every case the ratio 1:10 is good for the MC like Denon 103, with a impedance of 15-40 ohm.
If the MC has lower than 10 ohms and max of 0,2 mV the 1:20 is better.

With 1:10 and the Load of your phono, 47 k, the reflected Z on primary of the step up is 470 ohm.
With 1:20 it is 117 ohm.


Walter
 
Maybe a trans that can be wired for multiple ratios?

If you haven't decided on a cart. yet you might want to try a trans like the 1990 from Sowter, or perhaps the CMQEE-3440AH or CM-1254/CM-125PC from Cinemag. Having a one-winding trans will limit your cart. choice. Also if you change carts later on you won't have to buy another trans. There are Lundahls (available from K&K Audio in the US) that have multiple windings as well.

Your question regarding the RIAA resistor? Resistors R20, R21, R25 and capacitors C13 and C14 set the RIAA correction.

If you are going to the expense of MC carts and SUTs you might want a more accomplished phono amp than the one you show. I can vouch for the Tubecad Tetra.
DIY All-Tube Phono Preamp Project: It’s on! | Wall of Sound | Audio and Music Reviews


Steve
 
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