[les_garten]

Quote:

 
 
I do have an RCA black plate 6AS7G which I have been using as my main power tube and a GE 12AU7 for the preamp.  Both are tubes I randomly bought off ebay but so far I am very pleased with how they sound.
 

 
 
I go back and forth as well.  I really like the 6AS7s for voice.
 

 

[tdogzthmn]

Has anyone heard a GE 6AS7G 6AS7 blackplate with dual getters?  I got one off ebay to try against my RCA.

 

[JohnBal]

Has anyone compared the 2399 Tungsol/Chatham to a 5998 Tungsol. I recently ordered a Tungsol 5998 for my Darkvoice 336i from a retailer on the net who shall remain nameless. This was my first order from them. I corresponded via e-mail and then when I orederd, I actually called and spoke to a person (co-owner?) and we had a nice chat and confirmed he would send out a Tungsol/Chatham 5998. When the tube arrived, the tube was labeled 2399 and not 5998. Has anyone listened to both of these tubes? Are they the same sonicly? I have listened and I don't feel it is anything spectacular. I like my Bendix 6080WB better. Much more detail and HF extension. Not what I expected from a 5998, which from what I understand is quite detailed with nice frequency entension. I wanted one as an alternative to my Bendix. Now, if the 2399 and 5998 are the same tube, I guess I'll know I like the Bendix better in my system and not bother contacting the seller. But if they have different sound signatures, I'll approach the seller and ask why they shipped the 2399 instead.

 

[Skylab]

I have three 2399's, and they look exactly like my 5998's, and also sound just like them.  Since they all came from Tung-Sol, I am pretty sure they are the same tube, although why TS decided to change the number is beyond me.  There is almost no info on the 2399 available - it's not in the TDSL or the N7JP tube databases.  But I am pretty sure it's just a 5998.

 

[rosgr63]

I believe the 2399 has the same construction as the 5998 but it's electrically the same as the 6AS7G.
The 5998 is not exactly the same as the 6AS7G.
I have both but have not done any ABX tests.

 

[JohnBal]

Thanks for the info. I just wanted to verify that they do sound the same in other amps as I cannot compare it to an actual 5998 in my own. I appreciate your help. I have looked at pictures of the 5998, and from what I can see, they look the same.

 

[Skylab]

Quote:

I believe the 2399 has the same construction as the 5998 but it's electrically the same as the 6AS7G.
The 5998 is not exactly the same as the 6AS7G.
I have both but have not done any ABX tests.

Well that would be good, since indeed the 5998 is not the same as the 6AS7G - because it draws just slightly less heater current than a 6AS7G (and of course has the same pin out) it can safely be used, but in some amps the bias may not work well, since the 5998 has about twice the transconductance of a 6AS7G.  So if the 2399 is indeed 5998 constuction and 6AS7G specs, that might make it a better fit for many 6AS7G amps.

 

[hodgjy]

I just bought a "5998" from the same retailer you are probably talking about.  They sent me a 2399.  I had a very nice email conversation with the co-owner (great guy) and he gave me the history of Tung-Sol and Chatham.  Tung-Sol owned Chatham and they sold tubes under different names and numbers, probably as the result of different markets.  We concluded together it was a lot like Chevy trucks and GMC trucks (in the United States).
 
Rest assured, it's the same tube.
 
Quote:

Has anyone compared the 2399 Tungsol/Chatham to a 5998 Tungsol. I recently ordered a Tungsol 5998 for my Darkvoice 336i from a retailer on the net who shall remain nameless. This was my first order from them. I corresponded via e-mail and then when I orederd, I actually called and spoke to a person (co-owner?) and we had a nice chat and confirmed he would send out a Tungsol/Chatham 5998. When the tube arrived, the tube was labeled 2399 and not 5998. Has anyone listened to both of these tubes? Are they the same sonicly? I have listened and I don't feel it is anything spectacular. I like my Bendix 6080WB better. Much more detail and HF extension. Not what I expected from a 5998, which from what I understand is quite detailed with nice frequency entension. I wanted one as an alternative to my Bendix. Now, if the 2399 and 5998 are the same tube, I guess I'll know I like the Bendix better in my system and not bother contacting the seller. But if they have different sound signatures, I'll approach the seller and ask why they shipped the 2399 instead.

 

[JohnBal]

After digesting some of the information above, I am still not sure they are the same tube sound wise. I decided to contact the seller. The seller is a very easy person to communicate with as stated above. He decided that the 2399 was shipped in error due to an error that was made when the tube was boxed. Normally the 2399 sells for about 50% - 75% more that he sells the 5998 for, but he decided he would not have a problem with me just keeping the tube, or I could send it back to him for an exchange if I wanted. He said he just wants to make it right. I asked if he would have a problem with sending me a 5998 for regular price without paying the shipping charge. He said he would have no problem with that at all. In fact, he stated he'd get me his best 5998. So, I decided to order the Tungsol. Now I'll be able to compare the two in my amp anyway. I'll post my impressions when I get the 5998.
Thank you guys for your help.

 

[hodgjy]

Maybe we are dealing with different vendors.  I'm not one to dispute you, or your vendor, but the vendor I talked to said they are the same tube.  I am inclined to believe him because I could not tell any difference in sound at all between them.  I guess there's a lot of information out there that's not fully agreed upon.  I guess that's bound to happen when we're dealing with tubes made 50 years ago that are no longer widely used except for hobbyists.
 
But, I do thoroughly believe in all of the aspects of psyhoaccustics, to the point where we often think something sounds "different" or "better" because that's they way we think it should be.  So, in that regard, getting the true 5998 makes sense because that's what you want, and you should get it. 

 

[hodgjy]

One thing I've noticed, and I'd like others to confirm if possible.
 
When I use my 5998, my amp seems much cooler to the touch, including the siding and transformer housing, than when using other power tubes.
 
Is this others' experience as well?

 

[les_garten]

Quote:

One thing I've noticed, and I'd like others to confirm if possible.
 
When I use my 5998, my amp seems much cooler to the touch, including the siding and transformer housing, than when using other power tubes.
 
Is this others' experience as well?

My 5998 runs cooler than the 6080's

 

[hodgjy]

Thanks for chiming in.  I was reading some spec sheets on the various tubes in the family, and it seems like the 5998 has some operating parameters that seem like it should run cooler than other tubes.

 

[rosgr63]

My 5998's run hotter than my 6AS7G or 6080.

 

[Skylab]

I wouldn't think there would be a tremendous difference, really.  The 5998 draws 2.4 amps - the 6AS7G draws 2.5 A.  I wouldn't think that the 0.1 amp difference would be noticeable, but it could be. 
 
I haven't been using 5998's lately, but I confess I never really noticed if they ran warmer or cooler than 6AS7G's in my SP Extreme (my Extreme has been modded with a Electra-print transformer so that it isn't dangerous and can actually handle all the tube types the Extreme was originally spec'd to handle...)