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MC275 VI: Is it an impedance mismatch for vintage McIntosh tube preamps?

monkboughtlunch

monkboughtlunch

Super Member
Is the modern day MC275 VI an impedance mismatch for vintage McIntosh tube preamps such as the C11, C20, C22 and MX110? Would it not be a good sonic fit to use an MC275 VI with these vintage preamps?
 
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Ideally, its desirable to achieve a minimum of a 10:1 ratio between the input impedance of the amp and the output impedance of the preamp.
 
The owner's manual says amplifiers with input impedance of 100K ohm minimum should be used with the MX110. For the C22, it is either 47K or 50K(?). I don't what it is for the other models.
 
Most of the older tube pieces required a 150K or higher load. With those high impedances capacitance in hook up cables could be a real issue. Today with a very low output impedances of pre-amps its not really that much of an issue. But that doesn't mean you can use 98 cent cables either. The issue is the amount of current the old pre-amps can supply to the lower impedance loads everything else being equal. I wish there was a definite yes no answer. Unfortunately until some one like Terry Dewick or Ryan at Audio Classics can do some testing for us to give us solid information, I'm afraid you must trust your ears. Not a very satisfactory answer.
 
twiiii said:
Most of the older tube pieces required a 150K or higher load. With those high impedances capacitance in hook up cables could be a real issue. Today with a very low output impedances of pre-amps its not really that much of an issue. But that doesn't mean you can use 98 cent cables either. The issue is the amount of current the old pre-amps can supply to the lower impedance loads everything else being equal. I wish there was a definite yes no answer. Unfortunately until some one like Terry Dewick or Ryan at Audio Classics can do some testing for us to give us solid information, I'm afraid you must trust your ears. Not a very satisfactory answer.
Click to expand...

A quote from Terry from a 2011 thread regarding the MX110

"it can drive most any load over 10K with no ill effects, at 600 ohms you will have some bottom end roll off."

I've used my MX110 with a HK Citation 22 amp(22k) and can detect no negative impact. Sounds as great with it as it does with my Mac MC250. I would agree on the trusting your own ears part.
 
sberger said:
A quote from Terry from a 2011 thread regarding the MX110

"it can drive most any load over 10K with no ill effects, at 600 ohms you will have some bottom end roll off."
Click to expand...

So based on this can MX110 feed a signal to a modern production MC275 VI with no detrimental impact on sonic performance?
 
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