The rule of thumb is the input impedance should be a minimum of 10 times the output impedance of the source. If you do the math, it looks like you should be safe with any of your choices. I'm sure Al will correct me if I am wrong!

Phono amp output impedance/integrated amp input impedance problems

Hi everyone,

I have been shopping around for a new integrated amp for my all-vinyl system. In another thread (asking for integrated recommendations), I learned that I should be careful with the impedance matching with my tubed phono stage (500 ohm nominal output impedance). Our esteemed Almarg alerted me to the fact that I should probably be looking for an integrated with a line-level input impedance of 37.5k ohms to be safe, about 25k at a minimum. I did some research over the last couple of days into some integrated amps, and I was shocked to find out that a 37.5k minimum input impedance rules out nearly every amp I investigated: the Creek 100A, Parasound Halo, Exposure 2010/3010, Conrad Johnson CA150, Shiit Ragnarok.

Perhaps separates are a better choice? Or a SS phono stage?

Any thoughts on how to open up more options would be appreciated.

Best, Scott

I have been shopping around for a new integrated amp for my all-vinyl system. In another thread (asking for integrated recommendations), I learned that I should be careful with the impedance matching with my tubed phono stage (500 ohm nominal output impedance). Our esteemed Almarg alerted me to the fact that I should probably be looking for an integrated with a line-level input impedance of 37.5k ohms to be safe, about 25k at a minimum. I did some research over the last couple of days into some integrated amps, and I was shocked to find out that a 37.5k minimum input impedance rules out nearly every amp I investigated: the Creek 100A, Parasound Halo, Exposure 2010/3010, Conrad Johnson CA150, Shiit Ragnarok.

Perhaps separates are a better choice? Or a SS phono stage?

Any thoughts on how to open up more options would be appreciated.

Best, Scott

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