DIfferences in Philips Miniwatt 12AU7

Ok thanks!

I would say yes. They were produced to the same standard of quality, but who can say what has happened to them in the last 50 years.

Yes thanks! I am sure it is hard to pin point the differences in sound. I'm more interested in the quality of the production. Are Holland, Autralian and French productions equivalent in terms of quality?

It would be hard to say what differences in sound Phillips Miniwatts made in different factories would produce in your system.

Give Brent Jessee a call.  He may or may not have any Phillips Miniwatts, but he can probably help you find the tubes you're looking for.

I'm really hot on Gold Lyons lately, they do everything you want a tube to do.

Some Philips history to help you decide:

https://upscaleaudio.com/pages/philips-holland-factories

The Holland production is a safe bet. Only you can say if they help your system.

Also beware of tube generalizations (like “Mullard 12au7s sound warm”). I have a pair of Blackburn produced Mullards with Sonotone labels that are crispier and airier than anything in my collection.