[mordy]

After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
I am re-tired - rolling along...
Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:
The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
First impression is that these tubes have more bass than the RCAs in this setup. However, it is too early to describe the sound since the tubes are new - will need at least 30 hours; probably more.
But in this hobby the travel to reach the destination is also enjoyable...

 

[mordy]

After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
I am re-tired - rolling along...
Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:
The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
First impression is that these tubes have more bass than the RCAs in this setup. However, it is too early to describe the sound since the tubes are new - will need at least 30 hours; probably more.
But in this hobby the travel to reach the destination is also enjoyable...

Maybe someone knows the answer: I am always on the lookout for any electrical acrid smell from my equipment - always scary when it happens. Now I smell something from the amp, but it is not an electrical smell, more like a smell from old cardboard boxes or old newspapers. Could it be from the old Russian tubes?
I should also add that the tubes suddenly changed from a bright sound to a more mellow sound - around 12 hours into the burn-in process.

 

[bcowen]

Maybe someone knows the answer: I am always on the lookout for any electrical acrid smell from my equipment - always scary when it happens. Now I smell something from the amp, but it is not an electrical smell, more like a smell from old cardboard boxes or old newspapers. Could it be from the old Russian tubes?
I should also add that the tubes suddenly changed from a bright sound to a more mellow sound - around 12 hours into the burn-in process.

I can't offer anything of help on the smell. I have noticed that some old tubes smell kind of hot when first fired up. And I can't exactly explain 'hot', other than similar to turning on the stove burner without having anything cooking on it at first (if that even makes any sense).

IME, most every truly new (as in never used) NOS Russian-made tube I've tried improves quite a bit over the first 15+ hours of play time. From Svetlanas to Fotons to Melz, they all sound a bit thin, lack harmonic depth and detail and some can have a treble edge to them compared to how they sound after getting some break in time. Just my experience, but I've heard it so many times I don't think it's just a figment of my imagination.

 

[mordy]

I can't offer anything of help on the smell. I have noticed that some old tubes smell kind of hot when first fired up. And I can't exactly explain 'hot', other than similar to turning on the stove burner without having anything cooking on it at first (if that even makes any sense).

IME, most every truly new (as in never used) NOS Russian-made tube I've tried improves quite a bit over the first 15+ hours of play time. From Svetlanas to Fotons to Melz, they all sound a bit thin, lack harmonic depth and detail and some can have a treble edge to them compared to how they sound after getting some break in time. Just my experience, but I've heard it so many times I don't think it's just a figment of my imagination.

Exactly my experience with these Svetlanas! Thin sounding, with a treble edge. Better sound to come....I am sure.

 

[mordy]

After listening to the quad of RCA 6AS7G tubes for a while my impression is that they sound fine. In comparison with the 6336B there is less slam but more detail and the upper frequencies come through very crisp and clear. Not as musical but still very enjoyable together with the GE 6N7 tubes.
I am re-tired - rolling along...
Next a Russian - American collaboration - Owensboro and Petersburg (GE 6N7 and Svetlana 6AS7G). The Russian tubes are new and not burned in. There was a time when you could buy the Svetlana tubes by the case of 50 or 100 for very little but not any more. Sometime ago I bought a small lot of these tubes with loose bases and with a little assistance of crazy glue they are in use now:
The second tube from the left has a resemblance to the leaning tower of Pisa - did not pay enough attention when I glued it together, but it works.
First impression is that these tubes have more bass than the RCAs in this setup. However, it is too early to describe the sound since the tubes are new - will need at least 30 hours; probably more.
But in this hobby the travel to reach the destination is also enjoyable...

After some 15 hours suddenly there is a remarkable change for the better in sound. The only thing I can think of is this:

Becoming this:

The thin, harsh sound suddenly changed to a mellow, full sound. - They are people that claim that there is no such a thing as tube burn-in and that the tubes sound the same from being new to having been used for a while. IMHO they are wrong. However, I am used to a more gradual change than in this case.

 

[Xcalibur255]

Every NOS driver and power tube I've used has gone through this transformation from thin and flat to full and melodious. Not always to the same degree or in the same period of time, but they all do it to some extent. In fact one of the ways I'm confident that a tube I've just bought is truly NOS is if it sounds lifeless and has no bass the very first time I hear it. I also find find many tubes go through this "swing" in sound several times before settling down, each successive one milder than the first big swing. There's this weird 6th sense that kicks and you just "know" when it's finally settled down and this is what it's going to sound like.

I'm sure quite a few people think this is absolutely absurd and laughable, but if being a tube whisperer is crazy then it's my kind of crazy.

 

[mordy]

Every NOS driver and power tube I've used has gone through this transformation from thin and flat to full and melodious. Not always to the same degree or in the same period of time, but they all do it to some extent. In fact one of the ways I'm confident that a tube I've just bought is truly NOS is if it sounds lifeless and has no bass the very first time I hear it. I also find find many tubes go through this "swing" in sound several times before settling down, each successive one milder than the first big swing. There's this weird 6th sense that kicks and you just "know" when it's finally settled down and this is what it's going to sound like.

I'm sure quite a few people think this is absolutely absurd and laughable, but if being a tube whisperer is crazy then it's my kind of crazy.

Nothing crazy about it - this is the truth about what is happening when burning in new tubes. In some cases the tube will keep on changing for a hundred hours or even more, although the changes may become more subtle.
I chuckle when people do comparison tests of new tubes and take a bunch of them, play each one a few minutes, and then proclaim a winner.

 

[triod750]

My mystery 6C5G died on duty last night. First tube ever to do this. The heater stopped working.

I removed the metal shell by desoldering the tab connected to pin 1 (screen) and prying the 'lid' open and then separating the two halves. The tube had the marking SYLVANIA burnt into the socket. On the glass there was 6C5G in an oval.
I have one STC 6J5G that hums like crazy. It is beautiful but totally unlistenable. I dressed it in this metal shell and put it in the amp. It is now dead quiet.
The tab is now around the pin marked (m) on this link: https://www.radiomuseum.org/tubes/tube_6j5g.html It felt as the right thing to do.
When checking the 6C5G I found this source interesting regarding the metal shield: https://groups.io/g/tubecollectorsassociation/topic/66480356 My tube was intended for use in a radio. (Luxor was a Swedish company manufacturing radios and such items).

So if you have a tube that hums, you could try this solution...
I have a couple of L63 here that hums. Maybe....

 

[DecentLevi]

Hi guys, any opinions on these? It says Reflector 6C5S
https://www.ebay.com/itm/385077878640

 

[maxpudding]

Hi guys, any opinions on these? It says Reflector 6C5S
https://www.ebay.com/itm/385077878640

That’s Russian 6X5GT, a rectifier tube.

 

[mordy]

After some 15 hours suddenly there is a remarkable change for the better in sound. The only thing I can think of is this:

Becoming this:

The thin, harsh sound suddenly changed to a mellow, full sound. - They are people that claim that there is no such a thing as tube burn-in and that the tubes sound the same from being new to having been used for a while. IMHO they are wrong. However, I am used to a more gradual change than in this case.

After some time with the Svetlana 6H13C the verdict is that as a quad they acquit themselves well - nice sounding tubes with the 6N7 GE. But rollin' along...What's next? Dug out some 6080 tubes that haven't seen daylight for several years - bought when these tubes could be found used for $2 each in small lots, if you remember those days lol.
These RCA 6080 tubes put on a nice light show:

Two of the tubes are labeled Stromberg-Carlson. This company, founded by two enterprising Swedes, was a very large pioneer in communications equipment and consumer electronics. You can read about it here:
https://en.wikipedia.org/wiki/Stromberg-Carlson

Well, in comparison with the RCA 6AS7G, are these RCA 6080 New and Improved?
We'll give it a little time and see...

 

[Isaacc7]

If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.

 

[mordy]

After some time with the Svetlana 6H13C the verdict is that as a quad they acquit themselves well - nice sounding tubes with the 6N7 GE. But rollin' along...What's next? Dug out some 6080 tubes that haven't seen daylight for several years - bought when these tubes could be found used for $2 each in small lots, if you remember those days lol.
These RCA 6080 tubes put on a nice light show:


Two of the tubes are labeled Stromberg-Carlson. This company, founded by two enterprising Swedes, was a very large pioneer in communications equipment and consumer electronics. You can read about it here:
https://en.wikipedia.org/wiki/Stromberg-Carlson

Well, in comparison with the RCA 6AS7G, are these RCA 6080 New and Improved?
We'll give it a little time and see...

After using this combo for a little while I came to the conclusion that although the tubes have a nice mid-bass, they are too soft sounding and lack real slam and impact. They are OK, but in this combination they don't stand out.

 

[mordy]

If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.

Same here - trying to keep spending and collecting tubes down. I think the same seller had another lot of 100 6J5GT tubes recently.
I am not inclined to sell stuff and the few difficult buyers I have encountered in the past turned me off from selling.
It is tempting to buy a big lot cheap and keep the ones you want and sell the rest, but I know myself - it ain't happening...

 

[CAJames]

If anyone is interested, a seller just put up a bunch of American 6j5g tubes on ebay. Looks like there's a bunch of Raytheons that a poster here said are really good. I'm trying to keep my tube spending down and I need 4 at a time so I won't be going for these.

I wonder how those sell. Thanks to this thread I've got plenty of single triodes for this life and most of the next so my interest is strictly academic.