Why doesn't someone re-issue the 6386 tube?

[Silver Sonya]

I'm not a tube tech, so I don't know much about this stuff. But it seems like it's an important item and there's a demand for it. Why is it so scarce? It's probably a dumb question, but why doesn't Groove Tubes do a reissue or something, like they did for the G.E. tubes a couple of years back. I have a few of those in one of my Fender Twin-style guitar amps and they're amazing.

--- chad

[js1]

There's a small number of tube plants left (China, Russia, Slovak Republic). If you look at where tubes are used, it's pretty well restricted to music and audio applications. This ain't a large market.

Companies like Groove Tubes, Ruby, EH, etc., rebrand tubes made in these factories. In some cases, they'll have tubes made to their specs. But the engineering needs to be done and tooling has to be paid for in any case.

The 6386 is a tube that has limited application (used to be used as an radio frequency amplifier, as well as a gain control element). Given that tube radios aren't that popular anymore, it pretty well restricts its use to people building Fairchild influenced limiters.

If there's enough demand, someone will make it. Mind you, it won't be exactly the same - attempts to clone the qualities of other old tubes have been spotty at best.

js

[blackcatdigi]

(DISCLAIMER: The following is an old industry rumour posted for entertainment, ONLY)

I recall way back in the 80's as domestic tube supplies begin to seriously dwindle and china was the only source (before sovtek and other eastern-block suppliers were available in the west) a 'great' rumour: Supposedly, GT had seriously considered buying an old tube factory somewhere here in the states and manufacturing new tubes again, domestically. Unfortunately (for tube ethusiasts), they came to the realization that the output of the factory (in one production run) would vastly exceed the total amount of tubes they could ever expect to use and/or sell in a lifetime.

I've never remembered to ask Aspen, any time I've been around him (whether or not this rumour was true)... But I've always thought it was a great urban (audio) legend.

[Albert]

GT did buy some tube making equipment though, I've seen it at their factory here in the valley. So they make some of their own tubes, although they do test and rebrand probably most of the tubes they sell.

[nobtwiddler]

There is one company right now considering making that tube again!

As well, as a few others.
They are looking at all the problems / costs associated with bringing that tube to market once again.
Obviously the cost verses demand will be the deciding factor..
We will wait and see?

Paul
www.millbrooksoundstudios.com

[Zwinter]

6386 tubes aren't made because there isn't the demand. In the past these tubes were not only in professional audio, but also for the military. As the demand has gone down, they are of course no longer used in military applications, nobody has wanted to invest the money it would take your retool a factory to make them again. The professional audio market, unfortunately, just doesn't have the demand.

The 12AX7, however, has maintained a healthy supply through its use in guitar amplifiers, etcetera. Let's face it, tube manufacturers are there to make money, not to satisfy every gearheads desires.

[emrr]

An old wive's tale I've heard involves the glass used for the 6386. Supposedly, GE cooked up one batch of super-pure glass from which all production came, and attempts at production using other glass produced poor results.

Clearly, this sounds like it could be dubious BS, but it could be based in fact. The production scale required to make a specialized part at an affordable price seems out of reach given the demand. I recall asking some Russian contacts at Svetlana (1st US version) about the similar 2C51, and none of them thought it was feasible to modify and produce a stable gain reduction tube, even though it looks simple at a glance.