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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 26

post #376 of 10898

Dear Mordy,


I did and I wasn't aware of the fact that it was that much lower :/ but I am going with it as I have them and prefer the sound at the moment =). 500 hours could be a year, considering 10 hours per week. It is not that bad for those relatively cheap tubes. As I am still waiting for the 6N30P tubes, I haven't concluded the power tubes chapter yet.


Thanks for the hint.

post #377 of 10898

Hi all,


Sometimes you buy a tube that does not have the manufacturers name on it, but some letters are visible. I just found a little guide that identifies US manufacturers that made tubes for the military - JAN (or Joint Army and Navy tubes). May come in handy:

"Most tubes found today are ex-military, and carry Joint Army-Navy (JAN) designations in either a long form or an abbreviated version ahead of the tube type number. The known makers are: GE (JAN-CG or JG); Hytron (JAN-CHY or JHY); Raytheon (JAN-CRP or JRP); RCA (JAN-CRC or JRC); Sonotone (JAN-COZ or JOZ); Tung-Sol (JAN-CTL or JTL); Westinghouse (JAN-CWL or JWL)."


So, if you find a 6AK5 tube where you only can read the letters CG, you know it is a GE tube; a JTL tube means it is made by Tung-Sol etc..


Hope this is helpful in identifying tubes.

post #378 of 10898

Good info, thanks for sharing this!

post #379 of 10898

Thanks Mordy, very useful.

post #380 of 10898

Just a prelimnary information: I am having the opportunity to compare

Sylvania JAN 5654 (dark grey plates, halo getter, 1967) with

Sylvania JAN 5654W (black plates, halo getter, probably both 1974). The "no W" tubes still have to be properly burnt in.

Initial impressions are that they sound different: The JAN 5654 pronounces treble more, they sound a bit more spaceous (more reverb), also the JAN 5654 treble sounds harder. The JAN 5654W have more bass, sound rounder and a bit darker. So far, I prefer the black plate JAN 5654W tubes.

Edited by Acapella11 - 7/19/12 at 3:42pm
post #381 of 10898

Is there the possibility that there's a Sylvania JAN 5654 black plate with no W, because that's what my latest ebay purchase seller described it as. 

post #382 of 10898

I think that plate and getter design are part of the development of the tubes and the "W" stands for improvement.

Citation from thetubestore.com: "5654W (...) Replaces the 5654 tube or 6AK5-W tube types."


I have not found a file describing how the improvement was conducted. So, I presume that (for Sylvania) black plates and halo getter reflect the best of these tubes in this respect. "W" describes a later tube type in general terms. It is also not clear to me whether the "W" requires the black plates or is just a mechanical durability improvement for example. You could ask the seller which year the tubes are from. I would think they are rather 70s with black plates than 60s.

Alternatively, you could contemplate dbtubes.com to order from a variety of JAN 5654W tubes.


One small information more. When comparing the GE grey plate with the Sylvania black and grey plates, the Sylvania grey plates from 1967 are darker than the GE grey plates. A seller might be tempted to call them black if he has no real black ones around. Unfortunately, I have no camera here, which could visualize the differences.


Short Sylvania JAN 5654 W (1974) vs non W (1967) update after 20 hours of burn in: The "non-W" treble smoothed out. 

Edited by Acapella11 - 7/20/12 at 5:16pm
post #383 of 10898

Thanks for your insights! I guess this means that the tube hunting shall continue for now.. sticking to the RCA's 5654 for now till my Sylvania JAN 5654 arrives :)

post #384 of 10898

Just another update to the Sylvania JAN 5654W vs "non-W":

W sounds a bit fuller with more forward mids, slightly darker and houses more deep bass. The "non-W" is very nice too on the Q701, in summary the little brighter version with a bit deeper stage. I'll may come back to that later.


I am curious about your impressions after listening to your new tubes Categg :)

Edited by Acapella11 - 7/21/12 at 4:05am
post #385 of 10898

My Sylvania JAN 5654s wont arrive until a week later, hopefully they'll turn out nice enough. In the meantime still hunting for a pair of 5654 W version.. dbtubes.com seems abit pricey for me at this point, if ebay fails to turn up any 5654W tubes then only i'll purchase them from that site.

post #386 of 10898

Dear Categg, no need to worry. Sylvania 5654 (dark grey plates, halo getter) and Sylvania 5654W (black plates, halo getter) are similar in sound. With more burn in of the 5654, differences melt down. The 5654 is a bit brighter, which goes along with a little less bass extension. I could have been perfectly happy with the "non-W" if I wouldn't have known the darker nuance of the 5654W.


You could ask captainperry33 (ebay) whether he has some 5654W of choice. Looks like he got quite a stack of 5654 tubes there. Possibly, he could match them too.

Edited by Acapella11 - 7/22/12 at 11:13am
post #387 of 10898

It's funny since i bought my Sylvania JAN5654 from him, i never thought of asking him if he has any of the W versions though i suppose that can wait till i have tried out the non-W version first. I'm still pretty much trying to find the darkest sounding tube within the 5654 family. 

post #388 of 10898

Based on my personal experience and those of others on this blog, the 6N6P power tubes will help driver tubes sound less bright in the upper frequencies, compared to 6N6P-i.

post #389 of 10898

what do you guys think about the GE JAN5654W vs the RCA 5456 Black plate? I'm looking for one more set to go with my Voshkod's and Mullards

post #390 of 10898

Everyone really should get at least one set of EF92 and EF91 tubes.  Both these type of tubes are most likely going to be British and they have great soundstage vs the EF95 tubes.  Not saying they're better - just different and worth trying.

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