Ordered a S3X + C4S: And now...?

[tvr2500m]

I ordered an S3X + C4S. I am already enjoying a Crack, but wanted all my headphones, not just the Drop + Senn HD6XX, to get in on the Bottlehead fun. As I await shipment/delivery, I'm now either planning ahead or getting ahead of myself...

The 6FJ7 Compatron looks nifty enough, but poking around for replacement/rolling availability, it does look like there are loads more 6DN7s around than 6FJ7s. And more different manufacturers of 6DN7s. Reading about the choice to switch the S.E.X from the 6DN7 to the 6FJ7, it was about diminishing ability to supply 6DN7s for the S.E.X. But poking around a bit, the Compactron seems the rare bird now.

Maybe wire up my S3X with an octal socket to use the 6DN7? Kinda easy enough. Looking at the 6FJ7 pin out on the datasheet, four of the twelve pins don't connect to anything and/or aren't used.

[Paul Birkeland]

You could certainly put octal sockets in and use the 6DN7.  They got extremely scarce and expensive for a while, so we switched to the compactron.  They are internally identical, though it seems to be much easier to make a matched pair of compactrons, as there are fewer variants. 

[oguinn]

6FJ7 tubes are so cheap, too. I got a good stash for less than a set of 2A3s

[tvr2500m]

Thanks for the replies...

I'll ponder the octal/6DN7 thing...

Fewer variants... Boons and banes. Living for the last long time with gear that uses popular and large tube families  - 12AX/U/T7s, 6550s/KT88s/etc., EL34s/etc., 6CG7s, 6SN7s - the great thing is that there are so many tubes to choose from; and that's also the bad thing -- that are SO many tubes to choose from.

I didn't find in my searches so far good sources of 6FJ7s I consider to have extensive inventories or inexpensive prices. I haven't found many sources at all. If anyone might point me in the right direction, I'd certainly appreciate it.

Cheers!

[oguinn]

I emailed Dale at vacuumtubes.net and asked him for four matches tubes. With shipping it was $27. I also bought a bunch from eBay that have worked fine.

[tvr2500m]

Thanks. I'll drop 'em a line...

[tvr2500m]

Following up...

I'm still having some challenge finding 6FJ7s. I'm buying everyone out - all of the couple few tubes they have It does seem that the 6FJ7 Compactron isn't so very populous. I'm going to chill for now and just build up my S3X and give it a listen/enjoy it as is for a while, then take it from there.

[Paul Birkeland]

Well, I would estimate that for most people a pair of 6FJ7s will last about ten years.  How many are you trying to buy?  (How long do you plan to live?)

[tvr2500m]

Ha! I'm becoming acclimated to about to be using a tube that for the first time that doesn't have an unfathomably, overwhelmingly, impossibly large number of ceaselessly, hotly debated variants. I have worn output tubes to the nub (with several taking themselves out, occasionally with some drama), but very, very few smaller signal tubes. Of course, that doesn't mean that I don't have an ample store - well, more like hoard - of all the tubes I'll never possibly be able to consume to their last functional electron.

I have long ago gotten sober in my tube acquisition - and savvy about rolling. Experience can be useful.

Enjoying my Crack + Speedball, I like the way it sounds with just about any 12AU7 and 6080 combo, but I have certainly have rolled into some favorite duos. I was already hyper replete with 12AU7s coming into my Crack adventure. The 6080 was new to me. I now have a nice collection of 6080s and 6AS7Gs. The 12AU7 is a monstrously extensive family. The 6080 realm, much more delimited - and that can be kinda nice.

I've mentioned it before. Tube rolling is at the same time both a boon and a bane. I'm at peace with the relative dearth of 6FJ7 variation, and from what I can see the 6DN7 world isn't too much more extensive. And some folks have reported to me that there isn't such great sonic seasoning range among the different 6FJ7s.

I see GE and Sylvania 6FJ7s. That's a compact Compatron universe. Is there anything else? Who else made the 6FJ7? Can't I get at least a Tung Sol 6FJ7? Just one - well, two - 6FJ7s made by Tung Sol? Just for fun?

[Paul Birkeland]

I acquired a very large supply of 6FJ7s before we put the S3X on sale so we had some knowledge going in that the tube supply (well our tube supply) would be stable for 5-10 years.  There are Amperex and Tung Sol 6FJ7s, but they are really uncommon.

[oguinn]

I have about 14 laying around that I picked up over the past year from eBay and a couple online tube stores (two pair of balanced RCAs from the place I mentioned earlier in the thread). The brands I have are GE, DuMont (I think it's a rebrand of something else), Zenith, and RCA.

[tvr2500m]

Both the DuMont and Zenith are rebrands of some OE supplier. Neither had their own tube manufacturing. (DuMont did make CRTs and specialty tubes)

PB, did Amperex/Philips made a 6FJ7?? With etched coding, and all?? And Tung Sol?? My Tung Sol 6FJ7 may be out there somewhere??!!

I don't really mean to make a big deal of this. I'm Zen'ing out. I'm becoming one with the S3X and the 6FJ7. I strongly suspect it's going to be fabulous. If I someday wish for just a few more choices to roll, I'll install an octal socket to get at the 3 or 4 other variants the might be available with the 6DN7. That sounds like a lot of work for that...

[Paul Birkeland]

PB, did Amperex/Philips made a 6FJ7??

Ha ha, no.  I have some that are boxed/labeled as such though.

And Tung Sol?? My Tung Sol 6FJ7 may be out there somewhere??!!

The Tung-Sol printing is very convincing, but they are still rebrands.