[gibosi]

  OK...On a different note.
 
Be it coincidence, happenstance, or my ears...I seem to have settled on GE tubes after trying various E92s and E95s.
 
I would say my current top (3) are:
 
6HQ5
6EW6
6DK6
 
I'm still waiting on some 6DT6As and 6CS6s, arriving today...as well as EF91 Mullard 8083s, coming from Germany.
 
Anyway, while I wait on the parts for my C3G/6SN7 adapter plate build...
 
Do you think it would be reasonable to assume a good starting point for a 6SN7 would be to find a GE variant?

Any suggestions, within that realm??
 

 
Like Nic, my opinion regarding GE 6SN7s is that they are not very good. In addition to the brands he suggested, I would add CBS/Hytron. These are quite good and often overlooked.
 
In my experience, really good GE tubes are just not very common. The best I have found are 6AU6, 6AH6 and 1950's 6AV6. In my opinion, the GE 6AU6 is in fact better than the GE 6DT6A. Of the 6DT6, I liked the Tung-Sol and RCA the best.
 
Also, your GE 6HQ5/6HM5 might not have been manufactured by GE. The two variations I have were manufactured using Philip's factory equipment and were not even manufactured in the US.
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/8925#post_11255228
 
And speaking of GE tubes, today I received a couple of Sylvania 6463. The pictures weren't all that good and I doubted that they were actually made by Sylvania, but for $12 I figured it was worth the gamble. And as I suspected, these were manufactured by GE. To date, the only manufacturers of the 6463 I am aware of are GE, Philips (Heerlen) and Telefunken (Ulms). It appears that Sylvania never made this tube.
 
Notice the whitish dots under the tube number. This is a dead giveaway that these were in fact manufactured by GE. If you don't see the dots, then the tube was manufactured elsewhere and rebranded by GE. In this case, I think it was a bit of good luck that one has an O-getter and the other a D-getter, so perhaps late 1950s for the older tube and 1960's or later for the newer one.
 
The oldest one is burning in as I write this. And as the GE 6463 doesn't seem to get much love in the Google searches I have done, I don't expect it to be great, but time will tell.  
 

 

[buldogge]

I'll check those 6HQ5s later tonight...I know they were marked 'Made in the USA'...not sure if that matters.
 
As far as 6SN7s...I needed up buying a couple mismatched/re-labeled TS "Mouse-Ears" off eBay today.  One is labeled 'Admiral' and the other 'Rad-Tel'...the pictures weren't great, but they appear similar, if not identical.
 
The 6DT6 assortment I just picked up (all NOS) are 3x GE (?), 2x RCA, 2x Zenith, 1x TS, and 1x CBS/Hytron.
 
I also grabbed 2x RCA 6CS6s...Don't hold a lot of hope for these...been pretty disappointed in most of the RCAs I have tried.
 
TA
-Mark
 
Quote:

   
Like Nic, my opinion regarding GE 6SN7s is that they are not very good. In addition to the brands he suggested, I would add CBS/Hytron. These are quite good and often overlooked.
 
In my experience, really good GE tubes are just not very common. The best I have found are 6AU6, 6AH6 and 1950's 6AV6. In my opinion, the GE 6AU6 is in fact better than the GE 6DT6A. Of the 6DT6, I liked the Tung-Sol and RCA the best.
 
Also, your GE 6HQ5/6HM5 might not have been manufactured by GE. The two variations I have were manufactured using Philip's factory equipment and were not even manufactured in the US.
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/8925#post_11255228
 
And speaking of GE tubes, today I received a couple of Sylvania 6463. The pictures weren't all that good and I doubted that they were actually made by Sylvania, but for $12 I figured it was worth the gamble. And as I suspected, these were manufactured by GE. To date, the only manufacturers of the 6463 I am aware of are GE, Philips (Heerlen) and Telefunken (Ulms). It appears that Sylvania never made this tube.
 
Notice the whitish dots under the tube number. This is a dead giveaway that these were in fact manufactured by GE. If you don't see the dots, then the tube was manufactured elsewhere and rebranded by GE. In this case, I think it was a bit of good luck that one has an O-getter and the other a D-getter, so perhaps late 1950s for the older tube and 1960's or later for the newer one.
 
The oldest one is burning in as I write this. And as the GE 6463 doesn't seem to get much love in the Google searches I have done, I don't expect it to be great, but time will tell.  
 

 

[gibosi]

   
I'll check those 6HQ5s later tonight...I know they were marked 'Made in the USA'...not sure if that matters.
 

 
The "Made in Xxxxx" text on tubes is often a lie as is the brand. lol. I have seen Japanese-made tubes with "Made in Germany" and the Siemens brand, Soviet-made tubes with "Made in Gt Britain" and the Mullard brand, and on and on. After all, the silk-screened text and graphics were added after the tubes were manufactured, sometimes long after, even years, and the silk-screening was more about marketing and distribution than anything else.
 
Etched markings, such as the GE "dots" and Philips manufacturing codes, were put into the glass during manufacture, and I find these to be quite reliable. Otherwise, you have to go by construction details - plates, micas, grid posts, getters, bottle shape, and so on.

 

[bobbyblack]

Hello guyz,

I want to say a special thanks to gibosi and mordy for the EI 6HM5 tubes recomandation!Only 2 days on them and the sound is allready amazing with my HD650(i came from Mullard's CV4010),good bass,rich sound,non sibilant,i say almost neutral-I dont know for other headphones but for Sennheiser HD650/600 they are v.good!

 

[gibosi]

Glad to know you are liking them. Even though we all have different ears and different gear, it seems that these inexpensive and relatively unknown tubes please almost everyone.
 
Enjoy

 

[bobbyblack]

Thank you,i do!

 

[buldogge]

Hey gibosi...FWIW...The GE 6HQ5s I have also have 6HQ5 USA etching, along with (3) small dots and (1) larger dot below them....so I assume they are actual GE tubes.
 
Also, both the 6DK6s and the 6EW6s, which I also like, have etched dots...hmm.
 
-Mark
 
Quote:

   
The "Made in Xxxxx" text on tubes is often a lie as is the brand. lol. I have seen Japanese-made tubes with "Made in Germany" and the Siemens brand, Soviet-made tubes with "Made in Gt Britain" and the Mullard brand, and on and on. After all, the silk-screened text and graphics were added after the tubes were manufactured, sometimes long after, even years, and the silk-screening was more about marketing and distribution than anything else.
 
Etched markings, such as the GE "dots" and Philips manufacturing codes, were put into the glass during manufacture, and I find these to be quite reliable. Otherwise, you have to go by construction details - plates, micas, grid posts, getters, bottle shape, and so on.

 

[gibosi]

Interesting! The 6HQ5 is slightly different than the 6HM5, so perhaps GE made the 6HQ5 here in the states and procured the 6HM5 from other manufactureres.....
 
Edit: At about the same time we discovered the 6HM5, I was also exploring double triodes, so I didn't spend much time checking out all the 6HM5/6HA5/6HQ5/EC900 variants. I hope you will consider getting the Ei 6HM5s and some of the others and then let us know how they all compare. For those who do not wish to mod their LDs for more exotic tube rolling, impressions regarding how all these tubes compare could be very useful.

 

[mordy]

Hi bobbyblack,
 
Happy to hear that you like the Ei tubes. Do your tubes start up with fireworks?
 
Based on my several years of tube rolling experience, I have come to the conclusion that great tubes do not necessarily have to be expensive or rare. There are a lot of sellers out there that try to convince you otherwise, even perpetuating myths about special "great" tubes that only they sell.
 
One of the great features of this thread is that you have a group of patient, helpful and dedicated people that give their honest unbiased opinions and advice, based on their personal hands on experiences.

 

[bobbyblack]

Hi mordy,

Yea lots of peoples here like to experiment things with passion and dedication for music and equipment and this is a good thing for newcomers like me and by the way i'm allready thinking of the next move on my LD3 ,probably 5687 power tubes !

 

[Acapella11]

Just felt like posting some pics of the power tubes I am mostly using at the moment. For the Sylvanias, most of the writing is gone. One can just about make out JAN CHS in capital on the glass and "van" from Sylvania. Maybe you have any comments whether these particular 6SN7WGT, from your experience, are good ones or not 

  On the Tung Sol 5687 WA tubes are a few numbers. I assume that in 3223, the 322 is the Tung Sol manufacturer code plus another 3, then there are different year/week of the year codes: 5643 (dark grey) and 5652 (white). 
 

 
 

 

 

 

[gibosi]

  Just felt like posting some pics of the power tubes I am mostly using at the moment. For the Sylvanias, most of the writing is gone. One can just about make out JAN CHS in capital on the glass and "van" from Sylvania. Maybe you have any comments whether these particular 6SN7WGT, from your experience, good ones or not 

  On the Tung Sol 5687 WA tubes are a few numbers. I assume that in 3223, the 322 is the Tung Sol manufacturer code plus another 3, then there are different year/week of the year codes: 5643 (dark grey) and 5652 (white). 

 
The Sylvania 6SN7WGT is a great tube. I think it sounds very similar to the chrome dome 6SN7GT. Structurally, the only visible difference is the extra support rod in the mil-spec tube, but again, I don't notice any significant difference in sound. The only Sylvania 6SN7 I like better is the small-bottle 6SN7W from the 1940's, which has a bit more body in the mid-range.
 

 
It appears your Tung-Sols were manufactured only 9 weeks apart in 1956, so very likely they are identical. And since you like the Sylvania 6SN7WGT, I suspect that you would also like the Sylvania 5687WA.
 
Edit: Also, the 7044 and E182CC/7119 have the same pin-out as the 5687, so you might want to explore these types as well.

 

[Acapella11]

   
The Sylvania 6SN7WGT is a great tube. I think it sounds very similar to the chrome dome 6SN7GT. Structurally, the only visible difference is the extra support rod in the mil-spec tube, but again, I don't notice any significant difference in sound. The only Sylvania 6SN7 I like better is the small-bottle 6SN7W from the 1940's, which has a bit more body in the mid-range.
 
It appears your Tung-Sols were manufactured only 9 weeks apart in 1956, so very likely they are identical. And since you like the Sylvania 6SN7WGT, I suspect that you would also like the Sylvania 5687WA.
 
Edit: Also, the 7044 and E182CC/7119 have the same pin-out as the 5687, so you might want to explore these types as well.

 
Hi Gibosi, thank you for the quick response and your suggestions. Yeah, Sylvanias sound dynamic yet detailed with this lovely 6SN7 space perception.
Sorry, if I made myself not clear with respect to the 5687 year numbers: My first tube on its own has the year codes 5643 in dark grey at the getter flash and 5652 in white under the main label, the other has 5609 in dark grey at the getter flash and but main label has almost completely disappeared.
 
Edit: How are your Amperex 6463 tubes coming along?

 

[buldogge]

Any comment on later Sylvania 6SNTGTBs?
 
They look similar to earlier ones...but...the "chrome dome" is smaller, for sure.
 
I just picked up a "tested good" pair for $7...figure it was worth a shot.
 
I'll stick with these and the TS Mouse Ears, for now, for preliminary testing with my 6SN7/C3G adapter plate.
 
-Mark in St. Louis

 

[gibosi]

   
Hi Gibosi, thank you for the quick response and your suggestions. Yeah, Sylvanias sound dynamic yet detailed with this lovely 6SN7 space perception.
Sorry, if I made myself not clear with respect to the 5687 year numbers: My first tube on its own has the year codes 5643 in dark grey at the getter flash and 5652 in white under the main label, the other has 5609 in dark grey at the getter flash and but main label has almost completely disappeared.
 
Edit: How are your Amperex 6463 tubes coming along?

 
The etched 5643 is likely the date of manufacture and 5652 would be date the tube was silk-screened and packed. It would appear that the other tube was manufactured in 5609, so still quite close in time, and if the construction appears to be the same, likely identical.
 
I am still burning the GE 6463 in. Once done, and when I can find some time, will try to discern the differences between the Telefunken, Philips and GE. In casual listening, the GE actually sounds pretty good. Vocals bring back memories of the GE 6AU6. One comment I read about the GE is that it is often microphonic, but this is not the case with the two GEs I have. In fact it is the Telefunken that is slightly microphonic, but only when I tap on the amp. I don't hear any extraneous sounds when I tap on the desk, so not a problem.