The new Coda S5.5 amplifier: It's a "Petite Beast"!

preamp bal out 20 ohm ; A-S MP-60 bal input 200K ohm factor. 10,000x impedance bridge- Outstanding.

preamp bal out 20 ohm: Coda S5.5 bal input 10K ohm factor. 500X impedance bridge- Excellent.

Both are quite good but when you have two systems like this to compare, is it possible that in an A-B comparison you might audibly hear a relative difference with the larger impedance differential (MP-60) revealing better signal, tonality, bass, neutrality, more natural sound??? Again both amps independently may sound great but when you have both to compare,  and go from one to the other with the same preamp,  is this difference in the impedance bridge going to reveal itself audibly? I have experienced such  an occurrence; however, that does not mean it is common or even likely for your system or most. You may not know without actually A-B comparing. Perhaps others with more knowledge and experience can elucidate on this subject.

We are all aware that there are many other factors as well that can and will likely  contribute to sonic differences between the S5.5 and the MP-60 with speaker matching being a key factor. Even with the different preamp-amp impedance bridges, the numerous other differences between the amps coupled with their synergy with the rest of your gear and especially the speakers, may be far more influential on the audio quality than any impedance bridge difference. You have to expect there will likely be an audible difference and should you try the S5.5, hopefully you will find it  as enjoyable as the MP-60. From the great reviews on the S5.5, that's entirely a good possibility! 

@car123 

20 ohms is probably as low as it gets for pre amp output, and should match from an impedance perspective with any amplifier, balanced or not. 

@firefly627s 

preamp bal out 20 ohm ; A-S MP-60 bal input 200K ohm factor. 10,000x impedance bridge- Outstanding.

preamp bal out 20 ohm: Coda S5.5 bal input 10K ohm factor. 500X impedance bridge- Excellent.

Both are quite good but when you have two systems like this to compare, is it possible that in an A-B comparison you might audibly hear a relative difference with the larger impedance differential (MP-60) revealing better signal, tonality, bass, neutrality, more natural sound??? 

From what we read 1:10 as far as  impedance pre output:impedance power input is minimum, and 1:20 is better, but does it get better and better the greater this ratio is? 

I would "think" after a certain point, maybe 1:30? it doesn't make a difference, so the difference between 1:500 and 1:10,000 is irrelevant, and if one hears a difference it is due to all the other factors between different amps, but I am just throwing random numbers out there and guessing. I am sure there is some pre/amp combo that synergizes very well at 1:15, and there is a 1:500 pre:amplifier combo that sounds like Kakk. And there probably isn't a number that explains this. 

Maybe we could get a particular engineer to respond and give his answer considering the preamp in question is of his design? @atmasphere ? 

Thanks, guys, I appreciate the responses.  The M-60s are incredible amps, made better with all of the tube rolling I have done, but I am currently searching for different options, different flavors, and as I said above, a solid state amp for the summer, when the M-60s heat my listening room.  It's nice to have options!

Happy Holidays and Merry Christmas all! 

From what we read 1:10 as far as  impedance pre output:impedance power input is minimum, and 1:20 is better, but does it get better and better the greater this ratio is? 

@car123 @mclinnguy No. Once you get past 10:1 there really isn't any difference with that as compared to much higher.

@atmasphere thanks Ralph. Always appreciate your input on these threads.