Audio Note M6 phono tube suggestions

For those who like to “roll” tubes, the tube type is paramount. So you’ll get better or more useful information if you say what tubes are required in your AN phono. As for me, I think it’s a bunch of hooey, because tubes don’t stay the same over time, and because opinions are highly subjective and subconsciously biased. Plus I have decades of experience to support my cynicism.

I did some research myself. It seems that an important tube in the M6 is the 5670, which has a couple of other alphanumeric names (e.g., 2C51, 396A). The best ever apparently was made by Western Electric (396A). The GE version of the 5670 is readily available from Tube Depot. I’d start there. Also, there is probably nothing wrong with whatever AN used. Also, this tube type can be replaced in circuit by 6922, but you need a special socket adapter for that. Don’t try it without an adapter. If you did buy an adapter, then there are in turn a whole bunch of 6922 variants to occupy your thoughts. It also uses one 5687 and one ECC82/12AU7 in the audio circuit. All the other tubes are either for rectification or voltage regulation, and I would not mess with those. There are many brands of 5687 and many subs. Have fun. The 12AU7 is probably used as a cathode follower; I would ditch it for a 6FQ6 or 12FQ6 (find out what is the filament voltage and choose the FQ7 to match), both of which are dirt cheap and any of which sound better than a 12AU7 in my experience. If you must have a 12AU7, I would look for Amperex Bugle Boy.

Thank you some good information there. And I think you’re right knowing which tubes are present in the M6 would be a benefit. I will post those this evening