EL34B

Che differenze ci sono fra le EL34B (ad esempio le Tung Sol di nuova produzione) e le EL34 normali ?
hanno valori elettrici diversi ?

Nessuno sa aiutare il ns amico?

Qui il datasheet delle EL34B:

http://www.thetubestore.com/lib/thetubestore/tungsol-el34b.pdf

In sintesi mi pare di ricordare che abbiano un'impedenza più elevata, una gamma bassa più presente e dinamica. Riguardo al suono, ti posto questo commento:

They are a direct replacement. They use the plate voltage supplied by the amplifier. They are a slightly higher impedance tube which means they will bias differently that a regular EL34 (but still within the range of the bias pots). They will not damage your preamp tubes.

Review:

The Tungsol EL34B is likely to become the #1 choice of currently produced EL34 tubes. The build construction is great all around and the move to welded plates will likely keep “EL34 rattle” to a minimum over time. The manufacturer claims that this tube has a hint of 6L6 in its tone thanks to manipulating the plate impedance. This is absolutely true, but the effect is most notable when playing clean and to a lesser extent when the tube is driven hard. At lower volume settings you hear a very pure balanced tone with a bit of the 6L6 sparkle in the higher frequencies while providing a midrange that is a little less prominent than most EL34 tubes. The tubes were very open and airy. The bottom end was percussive in the 2x12 open back combo. When driven into distortion it starts off a bit crunchy like a 6L6 but as you push it, the sound blooms into that singing EL34 tone with great sustain and modest compression. I love these tubes. Over the years I’ve tested many tubes but this is the first time I’ve had to tell myself to stop playing and get on to the next set!

Tieni però conto che tutti quelli di cui ho letto sono musicisti!!!!!!!!!! Ed usano le EL34B negli ampli Marshall, Seymour Duncan e via andare...

Sembrerebbero valvole dal suono più corposo e grintoso sul medio basso, con una conseguente minor brillantezza in gamma acuta. In effetti con la chitarra sono notevolissime!!!