2. amps-preamps
  3. 161394-15838

Rotating (not rolling) Tubes

I have a McIntosh C2300 preamp. I rarely use the MM Phono stage and never use the MC stage. My question is, do the MC and MM tubes get as much use just being "on" as the main tubes. If not, would there be a benefit to rotating the tubes? Think of it as rotating tires on a car. Say every six months or so move the MM tubes to the MC slots and the MC tubes to the Main slots. 

I do have access to a decent tube tester, so I can test the tubes to see how the MM & MC tubes test against the main tubes, but haven't pulled the tubes to test. I did do a search and didn't find anything useful. Thanks for any and all advice.

ben77059
oldhvymec
5,101 posts
 
It's a good idea to check and rotate. Make sure they are staying matched, WHY? well the 2300 sounds a lot better with balanced HQ valves, at least in 'pairs". Good idea with a slight mod... 

My Macs all use 12AX7s, some the 12AT7 and 12AU7.. I normally buy in pairs...  unless I buy "lots", I can't remember buying a single valve in my life. Even Rectifier valves in pairs, because I run monoblocks too..

Just so you know, that 2300, can be quite a little nugget.. A pair of Tellies in the mains and, RCA, Volvo, Mullard, PSVANE... ALL have a wonderful "different" sonic signature... Different music, different valves... different sound... Have a little spice in your life... Enjoy...

Regards
ben77059 OP
29 posts
 
Thanks for the reply oldhvymec. You made me think of another question. If I replaced the tubes with better (more expensive matched) tubes, is it okay to just replace the two main tubes? It seems like it would, but as far as I know, power could be running through all the tubes, each one affecting the sound in a slight way.
tomcy6's avatar
tomcy6
2,583 posts
 
@oldhvymec If he’s not using the phono stages, would it cause any harm to leave those tube positions empty, no tubes? Or how about putting old past-their-prime tubes in the unused positions?

You will use up the tubes leaving them on even though there is no signal going through them, but not as fast as if there was signal going through them.
More to discover