MC901 monoblock tube matching Q


I'm new to tubes... I have 2x MC901 monoblock amps. Each amp requires 8x KT88, 4x 12AT7, and 2x 12AX7A tubes. Do I need to match all these tubes? And do I need to match tubes for both amps together (i.e. 16x KT88 matched, 8x 12AT7 matched, and 4x 12AX7A matched)?

Thanks for your help.

 

Ag insider logo xs@2xbattbot

The power tubes are in quads and the signal tubes are in pairs. You can just throw one in, it will work. How it will sound is a different story. I'd guess just fine.. How picky are you. 10 years from now, start looking..

My advice to you is to leave it alone.  You didn't spend a bazillion dollars on those jewels to f around with them.  Many years from now when you do need to service them, ask a pro - not a board full of "experts."

For simplicity, it's easier to just order replacement tubes from McIntosh, as needed.

I certainly wouldn't go replacing tubes until they have exceeded their normal life or, alternatively, fail prematurely.

From the owner's manual:

The MC901 will function optimally with any correct
tube type that is functioning within the design
specifications of the MC901. Only when a Tube falls
outside of the acceptable range will any diminishing
of performance be heard. Because McIntosh Tube
Amplifiers are engineered to use Tubes in a way that
does not rely on the Tube’s individual character and
can perform perfectly provided the specifications are
met, there is no advantage to seeking out expensive
esoteric tubes.
Over time, a Tube may fall out of the proper
specification range. New Tubes that meet the
MC901’s specifications can be ordered using the Part
Numbers on page 12. For the positions of the tubes,
see Figure 15. This pattern is found on each side of
the MC901