[gibosi]

I am conteplating getting a pair of Philco 6AS7G (believe 50's). These are made by RCA and would therefore sound exactly the same, or should I look for another pair? Budget could be stretched to $150 for a better pair if available.

 
Rebranding was very common. And in fact, Philco didn't make tubes. They made radios and televisions. So in this case, they bought a bunch of tubes from RCA, put their own name of them, and used them as replacement parts. So if you want a pair of RCA, these rebranded Philcos should be perfectly fine. But if you want something different, you might want to pass on these....

 

[oshipao]

Thank you for that gibosi,

What is your opinion on the RCA's vs Tung Sols equivalent, i.e. plain 6AS7G, no 5998, 6520, 2399 etc?

 

[gibosi]

Thank you for that gibosi,

What is your opinion on the RCA's vs Tung Sols equivalent, i.e. plain 6AS7G, no 5998, 6520, 2399 etc?

 
Personally, I like the Chatham/Tung-Sol 6AS7G better. But as always, different ears and different gear... YMMV

 

[attmci]

Thank you for that gibosi,

What is your opinion on the RCA's vs Tung Sols equivalent, i.e. plain 6AS7G, no 5998, 6520, 2399 etc?

You need to come here:
 
http://www.head-fi.org/t/806043/for-6bl7-tube-users

 

[hodgjy]

I am conteplating getting a pair of Philco 6AS7G (believe 50's). These are made by RCA and would therefore sound exactly the same, or should I look for another pair? Budget could be stretched to $150 for a better pair if available.

The RCAs are nice sounding tubes--warm, romantic--sort of like the feeling you get after a glass of red wine. But, RCAs are the noisiest 6AS7G tubes I've ever experienced. They are all noisy, but these have more.

 

[Mechans1]

  The RCAs are nice sounding tubes--warm, romantic--sort of like the feeling you get after a glass of red wine. But, RCAs are the noisiest 6AS7G tubes I've ever experienced. They are all noisy, but these have more.

I have also found that many of the 6AS7G tubes are noisy, even the 'domino' plate variants.  If your amp can take them 6080s have been less noisy in my experience.  I admit that the 'domino' plate, bigger  bottle tubes,  have overall superior sound.  The problem is getting some that are well behaved and quiet.

 

[hodgjy]

 
I have also found that many of the 6AS7G tubes are noisy, even the 'domino' plate variants.  If your amp can take them 6080s have been less noisy in my experience.  I admit that the 'domino' plate, bigger  bottle tubes,  have overall superior sound.  The problem is getting some that are well behaved and quiet.

Agree. 6080, 7236, and 5998A are lower noise.
 
The 6AS7 platform wasn't ever intended to be an audio tube, so I don't have any hard feelings towards noisy tubes.

 

[Johnnysound]

I have also found that many of the 6AS7G tubes are noisy, even the 'domino' plate variants.  If your amp can take them 6080s have been less noisy in my experience.  I admit that the 'domino' plate, bigger  bottle tubes,  have overall superior sound.  The problem is getting some that are well behaved and quiet.

Hi Mechans, I have around 10 pairs of 6AS7Gs (coke bottles, different brands) and none of them are noisy tubes at all. In my setup, of course. I would not characterize this "family" of tubes as noisy per se, and after reading many posts in this thread, it is clear for me that the noise problem is very system dependent. Some preamps, with some specific combination of tubes, are specially difficult, and I was amazed by some people struggling to find a "quiet" 6080 or 6AS7G !! I never found a noisy one, with the exception of one or two used, badly worn out tubes, but that was my fault for buying cheap crap...

And I also have maybe 18 6080s, my favorites are the NOS Mullards, (65' vintage) tied in the first place with the Tung-Sol/Chathams from 62', I think some of the very best 6080s you can find. And, subjectively, maybe the Mullards are more refined, but the americans hit harder with rock and the like... anyway, no 6080 can compare with a great 6AS7G in terms of air, space and three dimensionality....in my gear.

 

[Johnnysound]

Thank you for that gibosi,

What is your opinion on the RCA's vs Tung Sols equivalent, i.e. plain 6AS7G, no 5998, 6520, 2399 etc?

Hi oshipao, I concur with gibosi, one of our true experts here. The Chathams 6AS7G are great sounding tubes. Lets say they are the Tung-Sol "plain" 6AS7Gs, but of great quality, from there up , the 6520 is an "improved" version of the 6AS7G, and the 5998 is the "super tube" with higher specs. Very expensive, by the way. I am still searching for a good pair. But beware that a nice pair of Chathams is not easy to find, and I mean NOS or "almost new" tubes , definitely not cheap. The 6520s are even rarer, and I was lucky to get a pair of new tubes for a reasonable price. As good as the Chathams are, I feel that the 6520s, being very similar in its overall sound, are superior in some subtle definition of detail, and dynamics.

However, oshipao, there is no such thing as the best tube, it all depends on many variables, and I definitely say that the RCAs 6AS7Gs are some of the greatest "classic" tubes, with the sweetest sound and an enormous soundstage, ok., maybe not as defined as others, but if you are entering into this hobby, you simply must hear these great tubes. Try to get NOS ones, fifties production are excellent, and still available...

 

[hodgjy]

 Some preamps, with some specific combination of tubes, are specially difficult, and I was amazed by some people struggling to find a "quiet" 6080 or 6AS7G !! I never found a noisy one, with the exception of one or two used, badly worn out tubes, but that was my fault for buying cheap crap...

 

I wish I had your luck. My "luck" is probably due to my amp being very sensitive to tubes (I'd say 7 out of 10 tubes make noise in it) and my extremely sensitive hearing. I can't hear tube noise when the music is playing or if there is sufficient background noise in my home, but when it's quiet and I concentrate, I can hear the tubes making noise. Even my beloved 5998 tubes have a low level noise, but my RCA 6AS7Gs are by far the worst offenders. Heck, even one of my Tung-Sol 6AS7Gs is very noisy--I can hear it heating the filaments with my ear next to the tube, which then the amp picks up the noise and transfers it to my headphones.

 

[attmci]

  I wish I had your luck. My "luck" is probably due to my amp being very sensitive to tubes (I'd say 7 out of 10 tubes make noise in it) and my extremely sensitive hearing. I can't hear tube noise when the music is playing or if there is sufficient background noise in my home, but when it's quiet and I concentrate, I can hear the tubes making noise. Even my beloved 5998 tubes have a low level noise, but my RCA 6AS7Gs are by far the worst offenders. Heck, even one of my Tung-Sol 6AS7Gs is very noisy--I can hear it heating the filaments with my ear next to the tube, which then the amp picks up the noise and transfers it to my headphones.

@Hodgjy, I am with Johnny. You may have problem with your amp.

 

[mordy]

Hej Oshipao,
 
I have tried numerous 6AS7G variants and 6080 variants. If you want something less expensive that sounds better than the RCA 6AS7G tubes, try the 6AS7GA (any brand).
 
BUT, the very inexpensive 6BL7 sounds better than most, if not all, 6AS7 type tubes. This tube draws 1.5A, versus 2.5A for the 6AS7. Combining the 6BL7 with a 6SN7 tube, using a dual adapter, draws 1.5A + 0.6A = 2.1A, which is compatible with any amp using 6AS7 power tubes.
 
This combination is outstanding in sound quality and well worth trying.
 
Hi hodgjy,
 
Have you tried a Faraday cage to eliminate tube noise? Basically, you can use an inexpensive wire mesh basket or similar, and place over the tubes.
 

 

[hodgjy]

 
@Hodgjy, I am with Johnny. You may have problem with your amp.

It's a Woo. Some tubes are quiet, where other are noisy. I believe, maybe incorrectly, that if some tubes make no noise, the amp may be ok.
 
It's not a big deal because that amp rarely gets any use these days. I've significantly upgraded from it.

 

[hodgjy]

   
 
Hi hodgjy,
 
Have you tried a Faraday cage to eliminate tube noise? Basically, you can use an inexpensive wire mesh basket or similar, and place over the tubes.
 
 

I haven't. It's not a major deal---see the post above.

 

[oshipao]

Hi oshipao, I concur with gibosi, one of our true experts here. The Chathams 6AS7G are great sounding tubes. Lets say they are the Tung-Sol "plain" 6AS7Gs, but of great quality, from there up , the 6520 is an "improved" version of the 6AS7G, and the 5998 is the "super tube" with higher specs. Very expensive, by the way. I am still searching for a good pair. But beware that a nice pair of Chathams is not easy to find, and I mean NOS or "almost new" tubes , definitely not cheap. The 6520s are even rarer, and I was lucky to get a pair of new tubes for a reasonable price. As good as the Chathams are, I feel that the 6520s, being very similar in its overall sound, are superior in some subtle definition of detail, and dynamics.

However, oshipao, there is no such thing as the best tube, it all depends on many variables, and I definitely say that the RCAs 6AS7Gs are some of the greatest "classic" tubes, with the sweetest sound and an enormous soundstage, ok., maybe not as defined as others, but if you are entering into this hobby, you simply must hear these great tubes. Try to get NOS ones, fifties production are excellent, and still available...

Thank you.

Yes, I am not really willing splashing out almost $300 for a NOS pair of 5998. I guess I will have to try both, perphaps I end up liking the RCAs