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Does anyone know where I can get some tung sol, dumont and national union 12sn7gt tubes. These tubes are inexpensive, but I am not having much luck finding any of these better tubes. I will buy from a dealer or an individual; doesnt matter to me.
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I appreciate the useful comments, but back to my original question, does anyone know the best place to get some tung sol, dumont or national union 12sn7gt tubes? I have a want to buy ad in the classifieds if someone has some they want to sell.
is not the easiest to find and a choice of what type is even harder. The tube is inexpensive but there are less to find also. I have some rare black glass round plate but only one pair that I will be keeping. I will ask around though for the ones you are looking for.ja in clear and dark outside, Tucson, AZ
The Elaborate DAC=55/76 or 27 Balanced Preamp=Balanced Six Pacs=Newform Research 645
John, thanks! Your assistance would be much appreciated. I have contacted several on-line dealers and noboby seems to have them. Lots of Sylvanias, RCA clear glass and GE's but they are mostly gta's. Radio Electric Supply has hundreds of 12sn7gta's if anyone is interested. I bought some GE JAN 12sn7gt's and some Sylvania 12sn7gta's from them.
The 6SN7 family is one of the most debated types; I was offering my opinion. Many disagree-- this is what makes this a great forum. Though I rarely would admit it, I like the early 1960s GE 6SN7GTB with a square punch-hole on one side of the top-mica and a round punch hole on the other side. These are a $5-$10 tube. After I posted, I realized that the 12SX7 isn't really all that special; I just thought that for simplicity "get the 1940s RCA-CRC 12SX7" was simpler than detailing many types. I love Sylvanias too, and I REALLY love the grey-glass RCA VT231 ca. 1943--- the longplate Mullard 12AU7 in octal form.
Can you sub one of either of these for a 6SN7 with no mods? Any advantages?
6BL7 is a sub for the 6SN7.
I personally have quite a collection of tubes,including a few 6SN7.
New,old stock.
6BL7 is higher gm (and lower rp), lower mu tube. They both have the same pinouts, but when you put 6BL7 in the 6SN7 socket you can expect (depends of the circuit), say about 20-100% higher current through 6BL7, different Ua because of that, lower rp and lower amplification. Sometimes it`s not too important and you can do it, but in other circuits it IS important.
And "swap" can work only in this direction, don`t try to put 6SN7 in 6BL7 socket except you know the circuit and what you are doing.
And last, but not least - 6BL7 "pulls" 1,5A of heater current vs. 0,6A for the 6SN7.
12.6 and draws half the current. Otherwise they are the same.The 6SN7 is easier to find but the 12SN7 is much cheaper.
ja in warm, clear and dark outside, Tucson, AZ
The Elaborate DAC=55/76 or 27 Balanced Preamp=Balanced Six Pacs=Newform Research 645
Fergit the 12SN7; Get the RCA JAN-CRC 12SX7; it is identical to a 12SN7 electrically, but had tighter production controls, higher batch sampling, etc. "THE" 12SX7 has mid 1940s datecodes, bottom getters (rectangular)and is reputedly made by GE.(Just like GE made the Red Base RCA 5692)They are the best thing going in an octal medium-mu (6SN7 etc)except for the roundplate TungSols and damn near any 7N7 loctal. Nice treble like the Sylvanias but they have some meat in the mids. Great stuff. The tube center (I think) has them for $30. Just do a "12SX7" search. If you have a variable DC filament supply, don't forget about the 8SN7 too.
"The 12SX7 is simply 12SN7 selected for transconductance at Ua=28V...(Distortion) test shows no significant difference compared to the standard 6SN7/12SN7." - M. Jones, "Valve Amplifiers 3"
And (my comment) even little worse than average results... IMO - get (still cheap) "blackened glass" `40 RCA 12SN7.
You are missing one- Sylvania early 1940s 6SN7GT black flat stagger plate. Somewhat unknown, one audiophile stated runs neck & neck with Tung-Sol 6SN7 round black plate.I have watched these tubes in larger numbers disappear on AudioGon within hours at $95/pr.
Thanks g, I have been checking the 12sx7's out too. The search here has many positive comments about that tube and I know where I can get some of those. I just wanted to try the inexpensive 12sn7's first to see how they compared to my 6sn7's. I do have another question, how good are the JAN GE 12sn7's. If GE made the RCA's that are so highly thought of, has anyone tried the GE 12sn7's? I have managed to find and purchase a few of those. I havent heard them yet though as my amp isnt due for another week. I appreciate the knowledgeable responses I receive from the members on this board so I welcome any comments.
12SN7 grey glass. I find that the 12SX7, when I used it in my preamp, and when tried in my dac, to be slightly dull. I have a number of these and prefer some different types of 12SN7's to that tube. I also have many 6SN7's including 2 nos 1942 Tungsol round plate black glass, that are fantasitic but for me the 12SN7's are a much better deal and just as good.ja in dark and windy, Tucson, AZ
The Elaborate DAC=55/76 or 27 Balanced Preamp=Balanced Six Pacs=Newform Research 645
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