As quite a few of you know, Sylvania 5751 JHS or GB with 3 micas is considered to be “the holy grail” of audio tubes. However everybody is trying to purchase JHS version with black plates or GB version with gray plates. They totally look cool with all these gold pins or gold letters and if you collecting them, definitely go for gold, but if you want to buy them to listen to them… I will try to help to save you some major bucks and get the same famous sound. There will be no compromises, just a way to get the same gold brand but for $20-25 a tube – I got them as low as $15!!! I will focus on gray plates – I actually prefer sound of gray plates to black plates – it’s much creamier.
All my research and purchases show that buying Sylvania GB sound is very simple. Buy Sylvania 5751 with 3 mica. That’s it!!! They vary very little in internal structure, but not in sound. the tube on the left and center shows two variations of real Gold Brand with GB 5751 etched on the glass in both cases. First tube has square getter (like black plates) and only one plate staple per side. Other two (center and right) have two staples on one side and only one staple on the other side. I have not seen any other tube having this kind of structure. The two on the right have O getter. These are the only variations that I’ve seen – I’ve don’t a lot of research on the topic – I’m not ready to pay $100 a tube!!!
So forget about the color of the letters, they don’t affect sound! If you see Sylvania 3 mica 5751 – it can only be GB or JHS – which is exactly the same thing. Get it!