CBS-Hytron 5814A – Engineering Samples

CBS-Hytron 5814A - Engineering Samples

Once in a while, while going through a new shipment of tubes, I find some true treasures. This time it was an incredible find, the legendary CBS-Hytron 5814 tubes, but not just that, they were engineering samples from CBS-Hytron. Engineering samples were sent to various manufacturers to get acceptance and determine interest before starting mass production. Unfortunately, there is no date code on the box or the tubes, so it’s hard to say when it was produced exactly, but considering that 5814 tubes have been produced since October 1949, these are not far behind. Notice, that there is not 5814 label on the glass, just on the wrapper.

I’ve already written about these tubes and there are also posts about comparing them to other tubes from other contributors.

Favorite Tubes 12au7

Hi there, I’ve now listened and analyzed countless 12au7’s (and it’s equivalents) and thought I’d give my opinion on my current favorites.

1st Place Tie: Mazda 6189 Silver Plates 3-Mica and 50’s Valvo Long Plate Angled Getter

*these are somewhat similar to me in that they both have soaring/sparkling top-ends and beautiful midrange.  Both have lots of detail.  I think Mazda has better bass and is slightly more precise, forward and transparent.  But Mazda is also more dry.  Valvo is sexier and easier on the ears.  To me, the Valvos are a bit light on the bass.  Mazdas have maybe a larger soundstage, but Valvo is deeper and more intimate.  Tie for first.  If someone put a gun to my head, I’d choose the Valvos.

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