[Zuckfun]

Quick question guys. I was once told you should warm tubes up for at least half an hour, preferably an hour or more before a good listening session. I always adhere to this and I was just curious if everyone was the same?

15-20 minutes should be enough time for the amp/tubes to warm up to optimal conditions.

 

[mhamel]

The key is the factory/date code.   Some pretty knowledgeable tube experts out there have stated it over and over - if they are the same type, with the same factory/date codes, they are the same tube, regardless of the label.  You can see examples of it all through Brent Jesse's listings, I believe it's also mentioned on Tube World, Upscale Audio mentions it with their Amperex 7308s.
 
Different factories, wide date ranges, different getters - indeed all possible (and likely, imo) to have some sonic differences.
 
   -Mike
 
 
 
Quote:

But there was so much cross branding going on back in the day that it can be very difficult to say for certain that the tubes in question are identical. A lot of tooling and parts were shared among different factories.  And it's difficult to say for certain exactly what it is about a certain tube that gives it that special quality.  So if only one thing about the manufacture of a tube model was changed, the coating on the anode changed slightly for example, or the spacing on a grid, it becomes impossible to tell without actually listening if that tube will have the qualities you're seeking.
 

 

[nelamvr6]

I give my tubes at least 10 minutes, but I prefer to give them half an hour.  I personally don't think they need more than 30 minutes, but I understand that there are those who disagree.
 
And if I don't have 30 minutes, it doesn't bother me especially to start listening after only 10.

 

[nelamvr6]

Quote:

The key is the factory/date code.   Some pretty knowledgeable tube experts out there have stated it over and over - if they are the same type, with the same factory/date codes, they are the same tube, regardless of the label.  You can see examples of it all through Brent Jesse's listings, I believe it's also mentioned on Tube World, Upscale Audio mentions it with their Amperex 7308s.
 
Different factories, wide date ranges, different getters - indeed all possible (and likely, imo) to have some sonic differences.
 
   -Mike
 
 
 

 
You are of course correct.
 
I have tried to decipher the date codes, and I'm usually able to at least get a pretty good idea.
 
Personally I've never come across tubes with the same factory/date code and different branding.
 
I suppose that Brent Jessie and Mercedesman have much better chances of seeing this, they see hundreds of tubes, I only see a few.

 

[Oskari]

Quote:

But I am suggesting that OGs are really good tubes.  And if someone could guarantee 100% for certain that a particular tube was in fact the same exact tube with different printing on it, I'd want to buy that tube.  Especially since it would likely be a lot cheaper than an OG.

 
And I'm suggesting that the Philips tube plant in Heerlen didn't have separate lines (a) and (b) churning out tubes to be branded (a) Amperex and (b) all the rest.
 

But there was so much cross branding going on back in the day that it can be very difficult to say for certain that the tubes in question are identical. A lot of tooling and parts were shared among different factories.  And it's difficult to say for certain exactly what it is about a certain tube that gives it that special quality.  So if only one thing about the manufacture of a tube model was changed, the coating on the anode changed slightly for example, or the spacing on a grid, it becomes impossible to tell without actually listening if that tube will have the qualities you're seeking.

 
How exactly would an Amperex-branded tube be immune to all this?
 

And that's before you add the wrinkle of money.  As in, there are a lot of people out there who are aware that certain tubes are more desirable than others.  So they'll be willing to make all sorts of claims that are dubious, and even willing to make counterfeit tubes.

 
Ditto.
 

That's why I say if you want OGs, or Bugle Boys, or RTCs, or Seimens Halske CCa's, or Stuttgart Lorenz, or whatever, you're really a lot better off actually buying the tube you're looking for.

 
A brand, whatever brand, never guarantees anything. You need to know what you're buying.

 

[Oskari]

Quote:

It also helps if you recognize the Heerlen factory code ◿ visible in the photo.

 
I'm afraid the factory code symbol in the above doesn't appear correctly on everybody's screen. It should be a right triangle.

 

[nelamvr6]

Quote:

 
 
 
 
A brand, whatever brand, never guarantees anything. You need to know what you're buying.

 
We agree.

 

[Oskari]

Quote:

The key is the factory/date code.   Some pretty knowledgeable tube experts out there have stated it over and over - if they are the same type, with the same factory/date codes, they are the same tube, regardless of the label.  You can see examples of it all through Brent Jesse's listings, I believe it's also mentioned on Tube World, Upscale Audio mentions it with their Amperex 7308s.
 
Different factories, wide date ranges, different getters - indeed all possible (and likely, imo) to have some sonic differences. 

 
Thanks for bringing some sanity to this thread, Mike!

 

[nelamvr6]

You guys are absolutely correct. Tubes with the same model and factory/date codes will be identical.
 
But newbs need simpler advice when they're first starting out.
 
If they can find cheaper versions of great tubes by hunting for identical factory/date codes, that's fantastic.
 
But when they come in to this thread and all they want is to know which tubes will sound good, and someone recommends the Mullard CV2493, they would be well advised to look for exactly that tube.
 
They want advice, not the location of a reference manual.

 

[TonyRS]

Quote:

Quote:

I believe nelamvr6 has the LCD-2 and he highly praises the Amperex Orange Globes late 60's tube paired with this headphone. Hopefully he'll offer his perspective on the subject

 
 
You are correct.
 
I would also have high praise for the RTC E188CC valves.  And  there are other choices that pair quite well with the LCD-2s.
 
I prefer the Amperex Orange Globes primarily for the sliky smooth, "tubey" midrange.  But if you prefer a slightly less fluid, leaner midrange the RTCs are the tubes for you.  In most other respects, I'd rate these two tubes as a push.  They both have excellent bass response, fantastic treble, and amazing soundstage, presence and air.
 
You won't go too far wrong either way.
 
My list of favorite tubes is as follows:
 
[size=x-small]1. Amperex 6DJ8 Orange Globes 1968[/size]
[size=x-small]2. RTC E188CC circa 1967[/size]
[size=x-small]3. Amperex USN 6922 D Getter 1960[/size]
[size=x-small]4. Amperex 6DJ8 Bugle Boy 1966[/size]
[size=x-small]5. Amperex USN-CEP 6922 '60's.[/size]
 
[size=x-small]ANY of these tubes will sound at least great with the LCD-2 headphone.  [/size]
 
[size=x-small]But bear in mind, these are my favorites, I came up with this list using my ears and my preferences with respect to sound signature.  I don't think it's very likely, but it is possible for a person to reasonably disagree with every single one of my selections.[/size]

Where can i get the Amperex 6DJ8 1968 tubes? 

 

[nelamvr6]

Quote:

Where can i get the Amperex 6DJ8 1968 tubes? 

Mercedesman has a couple of pairs:
 
http://www.ebay.com/itm/AMPEREX-ORANGE-GLOBE-6DJ8-ECC88-VACUUM-TUBE-1960s-70s-MATCHED-PAIR-SWEET-NOS-/221229410098?pt=Vintage_Electronics_R2&hash=item33824ce732
 
It's not absolutely essential that you get '68's, but reports are that the O getters are better than the dimple disc getters.

 

[joydivisi0n]

Are O getter and halo getter synonymous?

 

[sceleratus]

Quote:

Are O getter and halo getter synonymous?

I'm probably the only dufus that uses "halo getter"
 
In other words.  Yes

 

[OldSkool]

Quote:

I'm probably the only dufus that uses "halo getter"
 
In other words.  Yes

I call the O-getters "halos" too, but I'm not glass-geek enough to call them "valves"

 

 

[sceleratus]

Quote:

I call the O-getters "halos" too, but I'm not glass-geek enough to call them "valves"

 

i resemble that remark.