I've talked to a supplier here in the US and discovered that JJ electronic REJECTS 70% of their own finished 6386 tubes.  JJ has set the bar high in terms of quality for their 6386.


EmRR

That's good to hear.  I hope they can sell enough to keep it going, and hone in on quality. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

lolo-m

That's good to hear.  I hope they can sell enough to keep it going, and hone in on quality. 
6386 is a mighty tube ! They did the only possible choice: making a real great tube. There's no use of the 6386 except in hi-end compressors now so... Selling hi-priced tube with no compromise in the quality is the only way to go...
There's always a use for a bad 12AX7 but not for a non-matched 6386.
Hard to be a punk... But sometimes you have to...

stickjam

  I've talked to a supplier here in the US and discovered that JJ electronic REJECTS 70% of their own finished 6386 tubes.  JJ has set the bar high in terms of quality for their 6386.

I'd make a joking comment like "where's their dumpster located?" but I'd bet the rejects are destroyed immediately after failing a test.  Somehow the 1970s movie "Willie Wonka and the Chocolate Factory" comes to mind.  ;D


EmRR

The last thing you want is your rejects slipping out into the marketplace via the black market, and soiling any good reputation. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

This post has been around for a while
What is the verdict - has anyone tried any of these new 6386 tubes???

maxheadroom

what makes the 6386 so great? or what can the 6386 what the other tubes can not do?
freddy get ready, it's time to rocksteady

EmRR

I'm not sure that anyone ever outright said it was great.  But who can argue with the legend of the fairchild and the stalevel.  Even if you own and dislike them!   ;D   A good one does a job well; an unbalanced one will drive you nuts.   It has a lot to do with the promise of a dedicated tube, useful for variable gain reduction, in a balanced push-pull package, in one bottle.  If you infer greatness by cost of new production, it seems to me that any of the commonly used tubes would cost as much if put into production again.  Especially when considering that there's only a single possible use, and sales will be limited.  6K7, 6SK7, 1612, 6ES8, etc etc etc. 
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde

what makes the 6386 so great? or what can the 6386 what the other tubes can not do?


For deeper info try a search, particularly with regards to posts from PRR. In a nutshell, the 6386 is a dual remote cutoff triode. Single RC triodes aren't exactly common, and the 6386 is the only dual RC valve I know of used in audio. Being in one tube, the sides tend to match well.

Justin
Prepare yourself. You are about to become the voice of Interplanetary Parliament.

PRR

> what can the 6386 what the other tubes can not do?

Be the front-end of a radio receiver which will handle both weak/distant signals and nearby/STRONG signals without much intermodulation. It may have originated in airline work.


PRR

Nothing to do with 6386 per se, but the thread is handy.

Radio Receiver Design (Part 1), K. R. Sturley, 1945, 435 pages
http://pmillett.com/technical_books_online.htm   CAUTION LARGE 17.7MB PDF file

Fig 7.19 plots the maximum undistorted input and output of a variable-gain IF stage.

I re-plotted with gain-reduction as the parameter.

When used as an audio limiter, maximum gain reduction is large output signal, but also low undistorted output signal. This sets a basic design choice for a limiter designer.

The plot shows outputs to 100V, but this is for tuned circuits which may have very high signal impedance with negligible DC impedance. A broadband audio choke/transformer will have impedance 10 times lower, and resistor-coupled loads even lower to keep DC shift reasonable.

  One has to respect that JJ Electronic chose such a difficult tube to re-create.  The 6386 has an exponential geometry grid that makes its manufacture a challenge.  We must be thankful that there are craftsmen in this world who still give a damn about quality.  To reject 70% percent of your finished tubes BECAUSE they do not pass spec is extraordinary.  Personally I love the idea that I can hack together a working comp/limiter based in these amazing tubes.  Peace, C

EmRR

So who the heck has a firsthand report at this point?  I can't find any?
Best,

Doug Williams
Electromagnetic Radiation Recorders

"I think this can be better. Some kind of control that's intuitive, not complicated like a single knob" - Crusty

"Back when everything sounde


 

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