For 6AS7G tube rollers here .....
Apr 25, 2022 at 9:02 AM Post #8,656 of 9,589
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Of course, I've read his post, he was just still trying to prove graphite plate 6080 will be 100c hotter than regular plate 6080, that's obviously ridiculous, there is nothing to prove an error, he mistakenly treated a tube's max heat rating as its actual heat generated and now he wanted to use a thermal gun to prove he's correct...I was like what?!

Then you stepped in and tried to say we were looking at the different things, and came up with the nit-picky thing on grid current, what do you expect me to respond...

No significant grid current will flow in class A1, we are talking pico amps of current with the grid biased negative, it will not contribute in any measurable way to the temperature rise or power dissipation. It's only significant in a class A2 amplifier, which doesn't apply to any 6AS7G OTL design.
 
Apr 25, 2022 at 9:26 AM Post #8,657 of 9,589
The last thing I want is to create arguments and name calling. I only reported on the stabilized operating temperatures of different 6080 tubes.
I have no technical knowledge and I am not out to prove anything- only report my observations.
If there is any interest in comparing temperatures of 6080 tubes to 6AS7 tubes I will continue; if not, I will stop.
 
Apr 25, 2022 at 9:30 AM Post #8,658 of 9,589
Apr 25, 2022 at 12:14 PM Post #8,659 of 9,589
The last thing I want is to create arguments and name calling. I only reported on the stabilized operating temperatures of different 6080 tubes.
I have no technical knowledge and I am not out to prove anything- only report my observations.
If there is any interest in comparing temperatures of 6080 tubes to 6AS7 tubes I will continue; if not, I will stop.
@mordy I would do just for curiosity sake.
For me (and @L0rdGwyn eventually dumbed it down for me, lol,) is that different tubes will show different temps based on their physical properties and how they handle thermal resistance.

I got a real world wake-up of this when I accidentally touched a Svetlana Winged C EL34 and burned myself.

Those get considerably hotter than other EL34/6L6GC types and now I know it’s probably due to it’s smaller size and therefore has a higher thermal resistance so it is not dissipating the heat as fast as a tube with more surface area In the same amp.

So if anything the former discussion was worthwhile for me.
 
Apr 25, 2022 at 1:03 PM Post #8,660 of 9,589
Rule of thumb is DAC/DAP all the way up, controlling your volume with the amp.
I however have always kept my amp about half way and control my volume with my DAC as it is more convenient given my setup.
To my ears I never noticed a difference either way.
When there is no line-out from the DAC, best way to put to full up as you mentioned. 👌
 
Apr 25, 2022 at 1:05 PM Post #8,661 of 9,589
There is no need to compare temperature on two tubes with the same specs. Both 6080 and 6AS7G draw 2.5A heater current, and they also have the same plate/grid voltage/current, so they must generate the same amount of heat from a scientific perspective.

If you measure some small difference, it must be caused by some other factors, such as kind of music that is playing (bass heavy music normally consumes more energy), individual tube variations (e.g. small variation in heater resistance), environmental, etc. But in general 6080 and 6AS7G should generate the same amount of heat.

5998/421A is a different story, as they have different specs than 6080/6AS7G.

6336/6528 are too hot to use with their 5A heater, you can imagine how hot they will be in summer...you definitely need to consider whether you can stand a furnace on your desk in summer...lol
As far as I know, the 6080 is the military rugged version of the 6AS7G although sound wise not that brilliant.
 
Apr 25, 2022 at 2:27 PM Post #8,662 of 9,589
The last thing I want is to create arguments and name calling. I only reported on the stabilized operating temperatures of different 6080 tubes.
I have no technical knowledge and I am not out to prove anything- only report my observations.
If there is any interest in comparing temperatures of 6080 tubes to 6AS7 tubes I will continue; if not, I will stop.
I very much enjoy posts from members like you who share their curiosities, experiments, and observations with everyone here. There are many of us who are here to learn and develop a deeper understanding. With any unexplored topics there are bound to be different opinions, observations, and basis of understanding. That’s what makes threads like these interesting to follow. I don’t get any joy from members who try to prove they are smarter than others, especially when name calling or other disrespectful comments are involved.
 
Apr 25, 2022 at 2:27 PM Post #8,663 of 9,589
I'm currently using my WA22 with all high gain power tubes Tung-sol 5998/7236 for my Denon D7000/Fostex 900/909 which are low impedance headphones. I was wondering if low gain tubes such as 6080/6AS7G will be better match. Thinking of picking these but not sure https://www.ebay.com/itm/313579532378
 
Apr 25, 2022 at 2:40 PM Post #8,664 of 9,589
As far as I know, the 6080 is the military rugged version of the 6AS7G although sound wise not that brilliant.
I am not sure if this is the case, but the 6080 is supposed to be a 6AS7G in a smaller envelope.
There were only two manufacturers of the 6AS7G in the US - RCA and Tung Sol / Chatham. Especially the RCA appears under many different labels.
There are numerous different 6080 makes and IMHO some of them may sound better than the ST types. —As always, the pairing and synergy with other tubes is the key.
It appears that the Russian Svetlana 6H13C and equivalents was modeled on the RCA version. It was made for both civilian and military use and in very large quantities.
This Russian tube is being sold under many fake names today at high prices, but is always easily identified by the double inverted saucer getters.
As far as I can remember, there are only US, Russian, British and Japanese 6AS7G tubes.
 
Apr 25, 2022 at 2:45 PM Post #8,665 of 9,589
I'm currently using my WA22 with all high gain power tubes Tung-sol 5998/7236 for my Denon D7000/Fostex 900/909 which are low impedance headphones. I was wondering if low gain tubes such as 6080/6AS7G will be better match. Thinking of picking these but not sure https://www.ebay.com/itm/313579532378
If you want to try lower gain 6080 tubes I would suggest Sylvania. They sound very good and are not expensive- a sleeper.
 
Apr 25, 2022 at 2:54 PM Post #8,666 of 9,589
If you want to try lower gain 6080 tubes I would suggest Sylvania. They sound very good and are not expensive- a sleeper.
Thanks Mordy. I guess I can always get better tubes down the line...
 
Apr 25, 2022 at 3:36 PM Post #8,667 of 9,589
I'm currently using my WA22 with all high gain power tubes Tung-sol 5998/7236 for my Denon D7000/Fostex 900/909 which are low impedance headphones. I was wondering if low gain tubes such as 6080/6AS7G will be better match. Thinking of picking these but not sure https://www.ebay.com/itm/313579532378
Treat yourself with those Mullards and also pick up the GEC 6080s from the same seller for a great contrast to your Tungsols. Both are on the warmer side of things.

Sylvania 6080 would be my least recommendation to be honest. Pick them up if you get them dirty cheap.

Low/high gain doesn't make a big difference on my Euphoria amp.
 
Apr 25, 2022 at 3:55 PM Post #8,668 of 9,589
Treat yourself with those Mullards and also pick up the GEC 6080s from the same seller for a great contrast to your Tungsols. Both are on the warmer side of things.

Sylvania 6080 would be my least recommendation to be honest. Pick them up if you get them dirty cheap.

Low/high gain doesn't make a big difference on my Euphoria amp.
I am checking temperatures of power tubes now on my Euforia - which driver tubes do you prefer with the above mentioned power tubes?
 
Apr 25, 2022 at 4:10 PM Post #8,669 of 9,589
I am checking temperatures of power tubes now on my Euforia - which driver tubes do you prefer with the above mentioned power tubes?
Rule of thumb for me is mostly one pair of warm tubes and one more neutral.

The Mullards are quite warm so something like Sylvania 6sn7w, melz 6h8s, Philips miniwatt, Hytron 6sn7gt come to my mind.

GEC 6080 are not overly warm so many matches here. All vt-231, melz 6h8s, b65, Sylvania 6sn7w and Bad Boys, would be my favourites.

I check only for sound 😜🎧
 
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Apr 25, 2022 at 5:47 PM Post #8,670 of 9,589
Treat yourself with those Mullards and also pick up the GEC 6080s from the same seller for a great contrast to your Tungsols. Both are on the warmer side of things.

Sylvania 6080 would be my least recommendation to be honest. Pick them up if you get them dirty cheap.

Low/high gain doesn't make a big difference on my Euphoria amp.
Just placed order for 2 pairs Mullard/GEC 6080s. Hopefully they sound great with Fostex 900/909.
 

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