I dig some of my collection and find some AZ1 tubes. Basically, I have several tubes, but short word, they are separated into 3 brands, Philips Miniwatt AZ1, Valvo AZ1, and Telefunken AZ1. I don’t use P-Socket on my system, but I could use my converter here.
Caveat before reading: This test result is purely subjective on my system. It could be different on your system. Take it as reference only, please 😉
First test is Philips Miniwatt. This tube has quite nice sound. The Ingram Washington’s vocal could be delivered sweet enough. Staging is not too wide, but depth is fine. The piano slightly light, less weight. When I first turn on the High Voltage, I see a blue spark. I think this tube is quite new, so probably need some time to break-in. Overall the tone are enjoyable, although slightly less weight.
We continue to the next contender, Valvo AZ1. Valvo delivered even sweeter vocal than Philips. The weight of the tone also become thicker. High is good. Staging is wide, but slightly less depth. All round performer, I think. Piano and sax also quite enjoyable with accurate weight.
We continue to the most favorable brand, Telefunken AZ1. Yes, it’s no surprise if people envy this Telefunken. It has sweet vocal, improved staging compared to Valvo, excellent mids, and high quality separation. Piano, Sax, and Brass are even more enjoyable.
Before I have compared RGN1064 between Valvo and Telefunken, which both has pros and cons (hard for me to choose). But for AZ1, definitely on my system and current tubes, Telefunken beats the Valvo.
I also take some photos to show even same brand may have different construction (and later, different sound to). See below. The tubes are the same, Valvo AZ1. But as you can see, the internal construction is different.
The Philips Miniwatt has added some solid plate on the top and bottom side of the mesh. Definitely this affect the sound, but they could provide stronger construction support for the mesh (and probably longer lifetime since the durability also improved).
Many more to play… Wait for RGN1064 shoot-out. I have some small and big mesh, and definitely more brands 😉
So much things to do, so little time. It’s 3:06 am morning, and it’s time to sleep 🙂