2. analog
  3. 125296-2238

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



smrex13

Showing 2 responses by bpoletti

bpoletti
1,004 posts
 
10 times, even 50x or 75x, is insufficient to provide optimal performance.  IMO, 100 times is a little better.  That being the case, there is no reason why amps have to have such low input impedances. 

There are solid state amps with a proper impedance so that you don't have to compromise the phono stage. 
bpoletti
1,004 posts
 
Use a separate preamp.  Quality tube preamp, or solid state.  They will have a realistic input impedance. 
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