Tube rolling on MacIntosh C2300

I want to try out some new tubes on my C2300 preamp. I only have one source, a DAC/Streamer and do not have a turntable. The preamp has 6 tubes of which 4 are for phono (2 MM and 2MC). Should I change the phono tubes as well or since I am not using the phono stage, it will make no difference? 


If you are not using the phono stage it will not make a difference. Save some money and ignore those tubes. 

I have a C2300 and highly recommend Amprex Medical Grade 12 ax7s, they are extremely pricey but ultra quiet, rugged and will last for years. I’ve had mine in for 4 years and my preamp is on literally 6-7 hours a day (as a passthru in my home theater system) and it sounds wonderful. I only use the medical tubes in the MC Phono stage and the Aux stage because I don’t have a MM TT. This is a great preamp that is smooth and sophisticated without the DAC on board, that is preferable to purists like me. I hope you continue to enjoy your C2300! 

I am an original owner of the C2200, which is similar to the C2300, and I have used various tubes over the years.  The C2200 uses four 12AX7 and four 12AT7 tubes.  I don't use the phono stage.

I just recently contacted Brent Jessee (who is well respected on these forums) asking his advice for tubes for this preamp.  He was very prompt in his reply to my email.  I will be ordering from him this week.

I suggest that you email him with your question.   His website is loaded with information as well:


That's what I hate about Mcintosh tube pre-amplifiers, they all come with a phonostage with lots of tubes. Which really sucks if you don't use a turntable.

They have a line stage with tubes.

So many people have phonostages they don't even use them. What a waste

Thank for all the great suggestions. Will definitely look into them. It will be nice to have quality alternatives instead of Telefunken which is crazy expensive.


I believe you can shut the phono section off, so, in effect, you will have 4 spare tubes. FWIW, I swapped the factory tubes on my C220 for Mullards, current production. They are quieter and slightly warmer sounding than the stock tubes.

I second the suggestion for the Amperex Medical Grade Bugle Boys. Years ago I too had a 2300 and used these tubes with great results.