MC901 monoblock tube matching Q

Looks like @crustycoot is correct. I called McIntosh again, this time got Chuck in technical support. He said neither the power tubes or signal tubes need to be matched in their amps or preamps. He did say it’s possible there may be a slight audible benefit if using matched sets, however. Guess that answers my questions. 

Get yourself a couple of spares,and call it a day. Sit back,and enjoy the music. 

It makes no sense to change tubes on a brand new amp. I don't think Mac would put inferior tubes in their statement monoblocks. I have a C1100 with the stock tubes & the sound is fantastic. Mac tech support told me that preamp tubes are good for 5 to ten years. 

@battbot 

hi,

Interested to know how your McIntosh tubes are working in the 901. Have you considered changing them out for something different?

Have you had any tube issues?

What speakers are you using?

I have 901s and have thought about trying new small tubes.  Not sure how much an impact using non-Macintosh tubes would have on the sound. I'm using b&w speakers right now, 802 d3.