The Reference 6J5 Thread (L63, 6C5, 12J5, 6P5, etc.)

[leftside]

Did a little A-Bing on the different Fivre 6C5G builds, I had not compared them critically before. There are easily discernible differences, the early black base are more airy and detailed than the brown, smoother, the brown base are a little more "up front and personal" in the midrange, the black base seem more even across the frequency spectrum, handle greater complexity of music with more ease, larger soundstage, more diffuse whereas the brown base staging is more round with more clearly defined boundaries.

Been doing a lot of tube comparisons today, it has been a while since I have. I acquired about half this collection of Fivre 6C5G while working on other things and never got around to doing any critical listening with the black bases. Since I already had them in and I was so impressed, I kept going and compared them to the gray glass GEC L63, can't believe it, maybe tastes are changing, but I prefer the black base Fivre...so they stay. Guess I have a new daily driver, maybe it is tube synergy or just my mood, I am seeking a sort of "easy on the ears" sound lately, which isn't to say the L63 aren't, but the Fivre are very chill and smooth. I'll double back in a few days to be sure.

I'll have to dig out the brown base and do a comparison. You'll definitely like the 76 as well. Mood has a huge impact on the type of music I listen to and the tubes I select. At one end of the spectrum is the 6C5, then the 6J5 somewhere in the middle and then the 6N7G. Obviously this is somewhat an over-generalization, and different makes and years of tubes have further subtle differences.

You'll swap out the 6C5 in a few days for the L63 and probably prefer the L63...

 

[chrisdrop]

I'll have to dig out the brown base and do a comparison. You'll definitely like the 76 as well. Mood has a huge impact on the type of music I listen to and the tubes I select. At one end of the spectrum is the 6C5, then the 6J5 somewhere in the middle and then the 6N7G. Obviously this is somewhat an over-generalization, and different makes and years of tubes have further subtle differences.

You'll swap out the 6C5 in a few days for the L63 and probably prefer the L63...

So 76s just a different base of the same lineage 76>6P5>6C5,6J5. Going back farther to 56 or even (ala @gibosi) 27s needs external heating. Do you just run them in the 6J5 slots w/ adapters in your 1101 Mischa amp?

More tubes to put on the watch-list. eBay has these pretty ones at the moment.

 

[leftside]

So 76s just a different base of the same lineage 76>6P5>6C5,6J5. Going back farther to 56 or even (ala @gibosi) 27s needs external heating. Do you just run them in the 6J5 slots w/ adapters in your 1101 Mischa amp?

More tubes to put on the watch-list. eBay has these pretty ones at the moment.

Yes. 76 to 6J5 adapters.My Fivre 76 didn't come with original boxes like those, but they were only 15 euros each.

 

[CAJames]

....More tubes to put on the watch-list. eBay has these pretty ones at the moment.

Very pretty indeed. Sadly I need a quad, and a winning lottery ticket.

 

[chrisdrop]

Hytron 6C5GT

Here is some general info on Hytron. According to this post (tx @rosgr63, you can see an old Bendix of yours in the background) the boxes appear to be older (pre CBS). It looks like CBS purchase was mid-50s, so these seem to be earlier than that. The date should be bounded between ~1941-1951. Not sure how to date them otherwise. There are 2 sets of characters: "2A5" and "M R".

EDIT: according to this the CBS merger was 1951


Anyone know how to date Hytron tubes? My 15 mins of google were not up to the challenge..

 

[mordy]

Nice find!
M R dates these tubes to 1942-1945. Vacuum tubes were rationed because of the war effort, but some were set aside for civilian use: M R means Manufacturers Replacement.
2 A 5? As you stated, very hard to find information on this small high quality Massachusetts manufacturer. My guess is February (2) 1945 (5). Or January (A)1945.
Rationing went into effect in May 1942 so it does not seem likely that the tube is from 1942.
Hytron was founded in 1921 and was bought by CBS in 1951 - production ceased in 1961.

 

[chrisdrop]

Nice find!
M R dates these tubes to 1942-1945. Vacuum tubes were rationed because of the war effort, but some were set aside for civilian use: M R means Manufacturers Replacement.
2 A 5? As you stated, very hard to find information on this small high quality Massachusetts manufacturer. My guess is February (2) 1945 (5). Or January (A)1945.
Rationing went into effect in May 1942 so it does not seem likely that the tube is from 1942.
Hytron was founded in 1921 and was bought by CBS in 1951 - production ceased in 1961.

Thanks @mordy. I got these in December last year, and haven't really put them in. They were inexpensive additions to a batch at that time. Going through my box, I though - hey, time to try! I suspect I have to put some hours on them as they are probably at 5h max at this point.

 

[mordy]

They are supposed to be good sounding tubes in general - I think Phantaminum liked the treble in a Hytron 6SN7.

 

[CAJames]

My adapters seem to be enjoying an extended layover in Arizona, sometimes that last hop is the hardest I suppose. So instead of listening impressions I can only offer a selection of tube porn c/o the latest USPS delivery:

Nation Union 6C5s in the top middle flanked by Raytheon and Sylvania 6C5GTs. On the bottom Sylvania JAN 6P5GTs and a "Wizard" 6P5G. All used, but in nice shape, none over 10 dollars. Can't wait to actually hear them.

 

[chrisdrop]

My adapters seem to be enjoying an extended layover in Arizona, sometimes that last hop is the hardest I suppose. So instead of listening impressions I can only offer a selection of tube porn c/o the latest USPS delivery:



Nation Union 6C5s in the top middle flanked by Raytheon and Sylvania 6C5GTs. On the bottom Sylvania JAN 6P5GTs and a "Wizard" 6P5G. All used, but in nice shape, none over 10 dollars. Can't wait to actually hear them.

I don't know the Wizard brand. Cool

 

[mordy]

Wizard is not a brand - it is a re-brander; a company that buys tubes from different sources and puts their name on it.
By looking at pictures of name brand tubes (eBay as an example) it is often possible to identify the manufacturer.
In the UK famous rebranders were Pinnacle and Haltron. Sometimes you can pick up great bargains under these names such as GEC tubes; at other times it is an inexpensive Russian made tube.
Because of lax laws such Russian made tubes could have Made in England printed on them.
The copyright laws in Germany were stricter but manufacturers found a way to get around it. Manufacturers such as Siemens would put their name on say a Japanese made tube and write “Foreign” on it without specifying the origin country.
Then you have situations where a name brand like Tung Sol needed to fulfill a government contract and didn’t have enough capacity to do it. No problem, just buy the same tube from GE and put the Tung Sol name on it! Problem is that those little sandblasted dots on the GE tube don’t come off so the tube has both the Tung Sol name and the GE dots.
In the late 50s and 60s cross branding was very common among US manufacturers.

 

[CAJames]

I don't know the Wizard brand. Cool

Exactly what @mordy said: I bought 4 6P5Gs branded Wizard, Zenith, Philco and Wards Super Airline. The dark side of the rebranders is that they would sometimes (often?) buy the primary manufacturers seconds, so while you can identify a name brand tube that has been rebranded it is hard to know if you are really getting name brand quality.

 

[chrisdrop]

Exactly what @mordy said: I bought 4 6P5Gs branded Wizard, Zenith, Philco and Wards Super Airline. The dark side of the rebranders is that they would sometimes (often?) buy the primary manufacturers seconds, so while you can identify a name brand tube that has been rebranded it is hard to know if you are really getting name brand quality.

Instead of 6P5s I am going to be inspired by @leftside and get some 76s. Of course, more adapters!

 

[CAJames]

Instead of 6P5s I am going to be inspired by @leftside and get some 76s. Of course, more adapters!

I saw that, and look forward to your experience. I've got plenty of octal tubes to keep busy....for now. Unless I can find a deal on 76 tubes of course .

 

[mordy]

I am not convinced that rebranders as a rule sold seconds. There may have been shady ones, but as a rule my impression is that most of them sold legitimate merchandise.
Jobbers may have bought overruns or surplus stocks, and individual department stores and manufacturers put their names on tubes, but it would not be in their best interest to sell seconds.