[Johnnysound]

Many thanks superdux, now it is clear for me:  the 7-pin socket needs an extender (socket saver), plus an adapter for the C3g tube.  BTW, the adapter is VERY expensive at $29.50 each plus shipping (¡¡)
On the other hand, I assume that (hopefully) the 6SN7 adapter goes directly into the 9-pin socket, 

 

[superdux]

Hi johnny, i just posted a link to some socket savers for your 6SN7 adapter, see post above
You just need them, if you have the MKIII and the gold rings around the socket.

 

[Johnnysound]

   
Yes, you plug your 6SN7 into the adapter, and then you plug the other end of the adapter into your power tube socket. So here is a pic of a nice Raytheon 6SN7W plugged into the adapter.
 

 
And Superdux has provided you with links to use a pair of C3g's. Since it is likely that your LD III has those gold rings around the socket, they are too narrow and do not allow the adapter to be plugged in, so you need the socket saver, which functions as a socket extender.
 
Here you go with pictures:
 
http://www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/6000#post_10512665

 
Excellent  ¡¡  Just saw this matched pair of old Raytheon 6SN7GTB, black flat plate top O Get, tested 80/82 (is this good?) Coded: G24 and I24, I assume compatible, again, different designation than your 6SN7W which look much more "vintage":
 
 
 

 
 
 
   
As you said in your earlier and very informative post, the investment with the C3g is considerable at around $ 140-$150 with adapters, but if it sounds so glorious, is worth the price of admission...I see tube stores charge even more for single tubes ¡¡  

 

[gibosi]

   
Excellent  ¡¡  Just saw this matched pair of old Raytheon 6SN7GTB, black flat plate top O Get, tested 80/82 (is this good?) Coded: G24 and I24, I assume compatible, again, different designation than your 6SN7W which look much more "vintage":

 
 
 
Actually, after further investigation, I have concluded that my 6SN7W was manufactured in 1959, so not as old as I thought.... Nonetheless, it is a terrific tube. And if you can get the Raytheon GTB's cheap, then yes, these would be great tubes to start your journey into 6SN7 land

 

[Johnnysound]

Hi johnny, i just posted a link to some socket savers for your 6SN7 adapter, see post above
You just need them, if you have the MKIII and the gold rings around the socket.

Thank you Superdux ¡¡   Yes, when I saw the 6SN7 adapter pic, it looked too wide for the MKIII...
In short: both the 6SN7 and the C3g need socket extenders and adapters...from 4 different suppliers ¡¡

 

[Johnnysound]

Got this matched quad "lightly used" ITT 6SN7GTB (Japan) for  39.95 plus shipping.  Looks like a good deal, seen the same quartet elsewhere for $100 or more ¡.   In the "6SN7 Addicts" thread they love this one, and say is the same tube as the famed Hitachi 6SN7GTB,   with a very interesting history: ITT bought Western Electric many years ago,  an then owned STC-Brimar  in the UK  from 1925 till 1982.   I concluded that ITT  must  know something about tubes. The "Addicts" say that these japanese tubes are very well made, and sonically among the "top three" favorites for some...we'll see.   Besides, better have some spares, just in case...  
 
 

 

[superdux]

if there's any ending at the name of the 6SN7 like "GTB" or "W" or somethin similar doeas that have to bother me, if i want to roll the tubes as power tubes in my LDMKIII?

 

[gibosi]

if there's any ending at the name of the 6SN7 like "GTB" or "W" or somethin similar doeas that have to bother me, if i want to roll the tubes as power tubes in my LDMKIII?

 
No.
 
The "W" just indicates that the tube was ruggedized for military and industrial uses. Since the 6SN7GT was used in television circuits, 6SN7GTA tubes were introduced to handle the increased voltage and power requirements of larger screen sizes. And again, the 6SN7GTB was introduced to provide a controlled warm-up time necessary for stringing multiple tubes together. As far as your LD is concerned none of these "enhancements" make a difference.

 

[superdux]

thx gibozi, you tube wizard, lol

 

[hypnos1]

Hi everyone....
 
A salutary lesson in how easy it is to be misled when assessing tubes :
 
Despite being an avid follower of (and erstwhile contributor to) this thread and having rolled many dozens of tubes (though nowhere near as many as some, lol!), I made a basic error in my latest test - viz. having been ordered (...no, encouraged!

) by mordy to do a shoot-out between my beloved C3GSs and some 5687s, I dutifully obliged and set to with my Raytheons - which had good reviews -  and being used, I assumed wouldn't need extended burn-in...they also came with very good test readings...
 
Anyway, to cut a long story short, they sounded terrible - not because of any fault in the tubes as such, but in every respect they were trounced by the C3gs. My mistake?...to assume the 5687 was nowhere near the C3g...silly me!
 
Luckily, I had also managed to snag a pair of '50s Tung Sols, so before writing off this tube family completely I popped them in just out of curiosity, and...WOW, the difference was unbelievable. How two tubes of the same family could sound so different took me rather by surprise - to say the least! I don't think I have ever come across such disparity in all the tubes I have tried in this past year (plus).
 
In short, even without much testing as yet, they are going to be VERY stiff competition for the C3gs. First impressions are that they give a slightly more forward and "fuller" sound - the bass hits a bit harder, especially - but perhaps at the expense of some "airiness" and holographic imagery (I have a feeling that there is always going to be a certain trade-off between these two "signatures", and that one has to choose which type is preferred*...unless an amp, or tube combination, turns up that can achieve miracles and marry the two successfully - a seemingly impossible task, perhaps?!).
 
And so, mes amis, the moral is try as many different flavours of a tube as you can before coming to a conclusion....which, of course, is what you all do already, no?! 

 
ps. It would appear, perhaps, that several reviews I have glimpsed are correct when they praise the virtues of the very early Tung Sol 5687s in particular...
 
Edit...*ps. Mind you, we rollers don't really have too much of a problem with this dilemma - we can just pop in the tubes we want depending on the mood, lol!...eg. C3g when we want to float dreamily through the heavens, and 5687 when we want to be "in the thick of the action", lol! (Or something along those lines

..).

 

[i luvmusic 2]

Anyone have tried these type of RCA tubes,are they better than clear glass?
 
THANKS!

 

[gibosi]

  Luckily, I had also managed to snag a pair of '50s Tung Sols, so before writing off this tube family completely I popped them in just out of curiosity, and...WOW, the difference was unbelievable. How two tubes of the same family could sound so different took me rather by surprise - to say the least! I don't think I have ever come across such disparity in all the tubes I have tried in this past year (plus).
 
In short, even without much testing as yet, they are going to be VERY stiff competition for the C3gs. First impressions are that they give a slightly more forward and "fuller" sound - the bass hits a bit harder, especially - but perhaps at the expense of some "airiness" and holographic imagery (I have a feeling that there is always going to be a certain trade-off between these two "signatures", and that one has to choose which type is preferred...unless an amp, or tube combination, turns up that can achieve miracles and marry the two successfully - a seemingly impossible task, perhaps?!).
 
And so, mes amis, the moral is try as many different flavours of a tube as you can before coming to a conclusion....which, of course, is what you all do already, no?! 

 
ps. It would appear, perhaps, that several reviews I have glimpsed are correct when they praise the virtues of the very early Tung Sol 5687s in particular...

 
There are early 1950's Tung sols and mid-to-late 1950's Tung-Sols. The ones that people seem to think are the best are the early 1950's. These tubes have flat, thin ribbed plates, quite different than the plates on the mid-1950's and later, and are often quite expensive:
 
http://www.ebay.com/itm/Matched-Pair-TUNG-SOL-JTL-5687-Black-Ribbed-Plates-D-Getter-E182CC-TUBES-/131293016241?
 
I don't have one of these so I can't say just how good they are. Mine is a 1956 tube, and while it is very good, it does not have the older plates.
 
The Sylvania 5687WA is my favorite 5687, so far, and recently, I have been listening to an RCA which sounds very good too. It has a bit more warmth, typical of RCA's, but all and all, it is very nicely balanced to my ears. So yes indeed, I suggest you try a couple more flavors.

 

[gibosi]

  Anyone have tried these type of RCA tubes,are they better than clear glass?

 
The differences people talk about regarding RCA's are related to the year of manufacture, and not smoked glass or clear glass. And as you might guess, people say the earlier the better. So while 1940's production might be a bit better, these should still be terrific.

 

[i luvmusic 2]

 

  Anyone have tried these type of RCA tubes,are they better than clear glass?

 
The differences people talk about regarding RCA's are related to the year of manufacture, and not smoked glass or clear glass. And as you might guess, people say the earlier the better. So while 1940's production might be a bit better, these should still be terrific.

THANK YOU!I think i'am getting addicted to 12SN7's they are cheaper than 6SN7's.
BTW i started using 6/12SN7's on the CRACK and i love them now, back then i really did not give them enough time to familiarize the sound of these tubes compared to 12AU7's i now know the difference between the two types of tubes(on CRACK).The 6/12SN7's have wider soundstage and more details than the 12AU7 but for the bass i prefer the 12AU7's bass for the CRACK.

 

[TheClarifier]

I could never thank Dept_Of_Alchemy enough for this guide (THANK YOU!!)! These posts and this guide got me to take the plunge with an MKll and I could not have been happier with it so far. I have some Voshkod 6ZH1P-EV drivers and some Russian 6H6P-1 power tubes that will be going into it tonight thanks to everyone's feedback. Once I got about 5 albums on the stock tubes they really started to come alive and I was already enjoying them. So if the stock tubes were going to get even better in time then I can't imagine what these new tubes will sound like down the road.   A question for the group... not that they would be necessary per se but I have seen pictures where people have small heat sinks that attach directly to the tube. One image I saw it was like a metal wire that clung to the tube halfway down and it had some small donut-like heat sinks looped in it that were resting against the tube surface. Are these helpful? Anyone know what they are officially called? I Googled for at least 30 minutes with absolutely zero hits. I wish I could find the pic again. There is a possibility this was part of a specific set of tubes and not an accessory. 
 
Edit: Found the pic! Halfway down this forum page. http://www.head-fi.org/t/364043/little-dot-i-tube-rolling/420    Thanks in advance for any info you can provide!