My “Tube Adventure” with STC4328A Small Punch and Mesh Shield
At the beginning of January 2022, I happened to come across the STC 4328A, a vacuum tube that had been on my mind for a long time, on the Yahoo Japan auction site.
The STC 4328A is compatible with the WE 328A, and the Western Electric 328A is the one that changed only the heater voltage of the famous WE 310A from 10V to 7.5V specification.
The reason why I wanted to hear the sound of this STC tube is that I once enjoyed a rectifier tube STC (Brimar) 5R4GY, which is practically the same as the STC itself printed STC 4274B.
By then, fortunately, I had been using and enjoying WE 274B engraved, they say “Holy Grail”, but I was no longer satisfied with the lack of the extension and beauty of its high frequencies. I felt the STC 5R4GY surely covered this slightly lacking point. If I may speak a little boldly, made in the UK tubes, including by Mullard, GEC, etc., would have the tendency to have a clearer and finer high range, is my experiences so far.
Also STC 5R4GY was the one of the good examples. In addition, I had long rated the mesh shield, the earliest model of the WE310A, manufactured in the 1940s, as the best, and had used it regularly.
But to be honest, my feeling of wanting to experience the sound of a different character might have sprouted. And the moment I found the STC 4328A small punch on the auction site, I had a hunch that this tube would let me experience a new sound world.
It was actually a tube with a high degree of glass transparency and beautiful in its appearance, which has a fine inner structure. This STC 4328A has the print marking, ITT 4328A made in England, on the glass. Around a half century ago, STC (Standard Telephones and Cables) was under the umbrella of ITT, a mega-conglomerate. And this tube might just be a service part for the telephone switchboard of ITT.
Well, the sound of my STC 4328A small punch was beyond my expectations. It was not only powerful but also so clear and transparent through entire range, as if enough to overlook the expanse of space behind the sound stage. And the timbre was also beautiful and full of contrast. The WE310A's sound is a bit old-fashioned and classic, but the STC 4328A's is very clear and far more modern.
However, this wonderful experience with the STC 4328A was only a small trigger, and more wonderful and the ultimate sound adventure awaited me.
I was fortunate enough to find and purchase a long-awaited driver tube, the STC 4328A mesh, made in Australia, on eBay USA in May of this year. According to the original and well-designed package, this tube was surely produced at STC's local factory in Sydney in the 50's, making it an extremely rare one, and my NOS STC 4328A mesh tube was just sent from Australia, one month after I bid it.
The sound of this mesh type was astonishingly outstanding, I felt. Although it shared the same basic clarity as the sound of the STC 4328A small punch, it has even more finer expression and a truly organic warmth. With just one listening of the sound, I realized and believed, that this was the ultimate top driver tube that I had been long looking for.
It seems that it is hardly recognized in the world of hobby audio, I believe, the PX25A (DA30) dome-shaped new type power triode’s excellent sound quality through the entire range, which can express such subtle differences very clearly, should also be given more focus.
Well, I’ve long evaluated GEC, Marconi or Osram U52, a UK made rectifier as the best rectifier tube, and described it that way.
But now I understand, the sound character of U52 with a slightly gorgeous, bright and elegant sound, could be a good partner for this somewhat deep flavor of this WE310A mesh.
If I make another expression, U52's bright tone could compensate well for the Western's a little bit darker tone. But for STC4328A small and mesh shield, I can’t say clearly which rectifier tube, STC5R4GY or U52 would be the best combination tube.
Yes, it would be true that they have definite differences in sound individuality, but I may no longer be able to talk about their superiority, because they both have in common a high-quality and elegant sound quality that is full of nuances.
Both can be said to be among the best rectifier tubes created, far more than a half century ago, in the British Empire. And now, I’m able to enjoy the music world with this all-made-in-the-UK tube line-up, including also the rare vintage direct heated power triode, GEC, Osram or Marconi PX25A (DA30).
In any case, I was able to realize once again how the desirable individuality of these vintage tubes, which are the active elements in the analog circuit, have a decisive effect on the sound and timbre in early 2022. This was really fruitful experiences, which was really a grand “Tube Adventure” for me!
