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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 533

post #7981 of 7994
Quote:
Originally Posted by gibosi View Post
 

 

This extra detail might help you to determine what is going on inside your adapter.

 

C3g   6AK5
     
1 heater -> heater
grid 3 -> grid 3
plate -> plate
grid 2 -> grid 2
cathode -> cathode
grid 1 -> grid 1
cathode -> grid 3
heater ->

 

heater

 

 

Thanks for this gibosi...

 

But now I am really confused!

 

I am certain that what I posted is how the happydiy998 adapter that works...is wired.

 

According to this, even the working adapter is wired wrong!?

 

What it make sound wired wrong?

 

I had noted that even with the "working adapter" I did not hear a "glorious rapture"...as expected...

 

Any ideas?

post #7982 of 7994
Quote:
Originally Posted by i luvmusic 2 View Post
 

The 1'' to 1/2'' will give you 1-1/8 to 5/8.But if you go to the hardware store asked them for 1 to 1/2 they don't include the wall thickness of the pipes. 

 

NOTE:

Copper Pipes comes in different types so the wall thickness and hardness varies. 

Most common types are Type M and Type L,Type L is thicker than Type M. 

When i say 1¨and 5/8¨i talking bore size .

post #7983 of 7994
Quote:
Originally Posted by MIKELAP View Post
 
Quote:
Originally Posted by i luvmusic 2 View Post
 

The 1'' to 1/2'' will give you 1-1/8 to 5/8.But if you go to the hardware store asked them for 1 to 1/2 they don't include the wall thickness of the pipes. 

 

NOTE:

Copper Pipes comes in different types so the wall thickness and hardness varies. 

Most common types are Type M and Type L,Type L is thicker than Type M. 

When i say 1¨and 5/8¨i talking bore size .

Are you looking to mount a 7 pin socket?

5/8 is the bore size for 1/2" fittings.

1-1/8 is the bore size for 1" fittings.


Edited by i luvmusic 2 - Today at 2:25 pm
post #7984 of 7994
Quote:
Originally Posted by i luvmusic 2 View Post
 

Are you looking to mount a 7 pin socket?

5/8 is the bore size for 1/2" fittings.

need 5/8 bore for 7 pin socket 

post #7985 of 7994
Quote:
Originally Posted by MIKELAP View Post
 
Quote:
Originally Posted by i luvmusic 2 View Post
 

Are you looking to mount a 7 pin socket?

5/8 is the bore size for 1/2" fittings.

need 5/8 bore for 7 pin socket 

Then you need a 1/2 fittings that gives you your 5/8 bore.

For 9 pin socket you need 3/4 fittings this is what i used.


Edited by i luvmusic 2 - Today at 2:35 pm
post #7986 of 7994
Quote:
Originally Posted by JazzVinyl View Post
 

What it make sound wired wrong?

 

I had noted that even with the "working adapter" I did not hear a "glorious rapture"...as expected...

 

Tubes can be wired up in all different kinds of ways, and they will often still work, but perhaps not sound so good.... lol :)

 

Taking a look at what you have found....

 

C3G         6AK5
1 heater ---------->3 heater
2 grid 3 ---------->2 and 7 cathode and grid 3
3 plate ---------->1 grid 1
4 grid 2---------->Not connected to any 6AK5 pins
5 cathode ---------->6 grid 2
6 grid 1 ---------->5 plate
7 cathode ---------->2 and 7 cathode and grid 3
8 heater ---------->4 heater 

 

Obviously, you should switch things around so that grid 1 and the plate are connected properly. And then, connect grid 2 in each tube. And since the C3g pins 5 and 7 are tied together inside the tube, you can leave 5 not connected. Also, it is useful to know that 6AK5 pins 2 and 7 are tied together inside the tube.

 

You have to remember that both the C3g and the 6AK5 are pentodes. And therefore, it is necessary to convert them into triodes. This is done by tying the extra grids, grid 2 and grid 3, to either the plate or the cathode.

 

In the EF95 setting, your amp expects to see a 6AK5 with the cathode tied to grid 3. And on the circuit board, the amp will tie grid 2 (pin 6) to the plate (pin 5). And thus, you have a triode-strapped 6AK5.

 

So first, we need to strap the cathode and grid 3 in the C3g together. And the adapter you have does this by tying them to the strapped cathode and grid 3 in the 6AK5. Second, grid 2 of the C3g must be aligned with grid 2 of the 6AK5 so that the LD can strap grid 2 to the plate. Once that is done, it is a simple matter to make sure the heaters, cathode, grid 1 and the plate are lined up correctly.

 

So this should work:

 

C3G         6AK5
1 heater ---------->3 heater
2 grid 3 ---------->2 and 7 cathode and grid 3
3 plate ---------->5 plate
4 grid 2---------->6 grid 2
5 cathode ----------> not connected
6 grid 1 ---------->1 grid 1
7 cathode ---------->2 and 7 cathode and grid 3
8 heater ---------->4 heater 

post #7987 of 7994
Quote:
Originally Posted by gibosi View Post
 

 

Tubes can be wired up in all different kinds of ways, and they will often still work, but perhaps not sound so good.... lol :)

 

Taking a look at what you have found....

 

C3G         6AK5
1 heater ---------->3 heater
2 grid 3 ---------->2 and 7 cathode and grid 3
3 plate ---------->1 grid 1
4 grid 2---------->Not connected to any 6AK5 pins
5 cathode ---------->6 grid 2
6 grid 1 ---------->5 plate
7 cathode ---------->2 and 7 cathode and grid 3
8 heater ---------->4 heater 

 

Obviously, you should switch things around so that grid 1 and the plate are connected properly. And then, connect grid 2 in each tube. And since the C3g pins 5 and 7 are tied together inside the tube, you can leave 5 not connected. Also, it is useful to know that 6AK5 pins 2 and 7 are tied together inside the tube.

 

You have to remember that both the C3g and the 6AK5 are pentodes. And therefore, it is necessary to convert them into triodes. This is done by tying the extra grids, grid 2 and grid 3, to either the plate or the cathode.

 

In the EF95 setting, your amp expects to see a 6AK5 with the cathode tied to grid 3. And on the circuit board, the amp will tie grid 2 (pin 6) to the plate (pin 5). And thus, you have a triode-strapped 6AK5.

 

So first, we need to strap the cathode and grid 3 in the C3g together. And the adapter you have does this by tying them to the strapped cathode and grid 3 in the 6AK5. Second, grid 2 of the C3g must be aligned with grid 2 of the 6AK5 so that the LD can strap grid 2 to the plate. Once that is done, it is a simple matter to make sure the heaters, cathode, grid 1 and the plate are lined up correctly.

 

So this should work:

 

C3G         6AK5
1 heater ---------->3 heater
2 grid 3 ---------->2 and 7 cathode and grid 3
3 plate ---------->5 plate
4 grid 2---------->6 grid 2
5 cathode ----------> not connected
6 grid 1 ---------->1 grid 1
7 cathode ---------->2 and 7 cathode and grid 3
8 heater ---------->4 heater 

 

I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).

Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters :o

post #7988 of 7994
Quote:
Originally Posted by vic2vic View Post
 

 

I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).

Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters :o

Bingo, that is exactly what has happened, reverse pinout.

Good Catch!

post #7989 of 7994
Quote:
Originally Posted by vic2vic View Post
 

 

I just noticed a thing, driven by the comment of the "unconnected" pin: if you consider the C3G pin connections provided by JazzVinyl in reverse order (8-->1 instead of 1-->8), you actually got the same connections proposed by Gibosi (except for the heaters and 2/7, which are shortened anyway. Would it work anyway?).

Maybe it's only a problem of reading the pins in the wrong sequence. It happened to me a couple of times when preparing other adapters :o


Wow...you may be on to something, vic2vic!

 

I counted them in this fashion:

 

post #7990 of 7994
Quote:
Originally Posted by bbmiller View Post
 

I seek understanding as to why in this article the person writing it has called the 6H30 - 6N30 tubes the Supertubes! I do not know if I be so enthused that I should try to purchase one of these tubes as power tubes. (For one thing I do not know if any of them they should be significantly different sounding from 6h30pi which already comes with my little dot IV MK SE.) But if you believe the article these parameter values are very significant to its sonic excellence, so let me quote what the writer of the article claims are parameters of sonic excellences and ask you why these are parameters of sonic excellence?

Quote:
6H30 has Amplification factor 15, Plate resistance 200 Ω, Transconductance 72 mA/V and it is very linear

 

So can you explain to me here why these are parameters of sonic excellences or alternatively suggest readings, searches, or links which might yield the answer to me? I think I have the linearity one licked, but if you could help me with those of the parameters I would be greatly appreciative.

Originally Posted by mordy View Post
 

Hi bb,

 

Heard about Superman? Supertubes? The humble people on this forum have listened to and compared the supertubes to other power tubes of the same family, and different ones as well. The 6H30-DR so called supertubes are only incrementally better than the much less expensive 6N6P-IR tubes (mainly slightly better bass). The conclusion is that in relation to the Little Dot amp, the supertubes are marketing hype.

 

For very little money, the 6SN7 garden variety octal tubes used as power tubes are much better (only need adapters to work in the LD), and the 6AS7/6080 are even better but the latter need adapters + an external power supply.

 

Man, this is crazy - just checked EBay  for supertubes. They go for $250-350 each! Three years ago u could pick up a pair for $100. And there are only half a dozen offerings...6N6P-IR tubes go for $34-41/pair today.

 

There are only some 2500 listings for 6SN7 tubes, and about 500 for pairs. What do I mean with garden variety? Right now, today, u can pick up rebranded Sylvania tubes for $15-18/pair including shipping Buy it now. IMHO a pair of these will sound better than a pair of supertubes for $700. However, they don't come with bragging rights - Zenith? Capeheart? Silvertone? Radioshack?!

 

Let your ears judge....

 

Quote:

Originally Posted by gibosi View Post

 

I suggest you try a few different 6SN7's, gray-glass RCA, black-glass National Union, chrome-top Sylvania and "mouse ears" Tung Sol, to see what you like. I encourage you to seek out the earliest tubes you can afford, but as Mordy will attest, there are some very good-sounding 6SN7GTB's to be had for not much money.

 

Further, there are a number of very informative threads devoted to this wonderful tube:

 

http://www.head-fi.org/t/209782/the-6sn7-identification-guide

 

http://www.head-fi.org/t/117677/the-reference-6sn7-thread

 

http://www.head-fi.org/t/479031/6sn7-tube-addicts

 

Have fun! :)

 

Edit: Oh, mid-1974-1979 Voskhod 6N23P's are also excellent, and they do not require an external heater PS.

"$15-18/pair including shipping Buy it now. IMHO a pair of these will sound better than a pair of supertubes for $700. However, they don't" come with bragging rights - Zenith? Capeheart? Silvertone? Radioshack?!"


OK requoting Mordy  from my quote middle above $15-$18 for a pair sounds awful good but as explained on this thread and with all those links above from gibosi 6SN7 is part of the 6SN7 enormous universe. So were I to jump on those other threads suggested by gibosi we you can learn more a bout  6SN7 enormous universe, to push finding the best possible 6SN7 or at least give it my best try, would I be looking for one that looks like the parameters in the quote of myself above if possible?


Also forgive me very much for forgetting, but now that I am getting into to rolling in a more serious way what exactly is the adapter required in the power tube socket to use the 6SN7 octal's. Looking at the data sheet from the stock power tube 6h30pi it appears we are going from a mini glass envelope nine pin with pin nine grounded to an larger octal?


Edited by bbmiller - Today at 3:58 pm
post #7991 of 7994
Quote:
Originally Posted by JazzVinyl View Post
 


Wow...you may be on to something, vic2vic!

 

I counted them in this fashion:

 

 

This is the view when you look down on the tube while holding it upside down. When working on this adapters, you are essentially looking at the bottom of the C3g, counting pins from left to right, clockwise, and looking at the top of the 6AK5, counting pins right to left, counterclockwise. Keeping these two orientations straight while working on an adapter can be be quite a challenge.

 

Good luck! :)

post #7992 of 7994
Quote:
Originally Posted by bbmiller View Post
 

OK requoting Mordy  from my quote middle above $15-$18 for a pair sounds awful good but as explained on this thread and with all those links above from gibosi 6SN7 is part of the 6SN7 enormous universe. So were I to jump on those other threads suggested by gibosi we you can learn more a bout  6SN7 enormous universe, to push finding the best possible 6SN7 or at least give it my best try, would I be looking for one that looks like the parameters in the quote of myself above if possible?


Also forgive me very much for forgetting, but now that I am getting into to rolling in a more serious way what exactly is the adapter required in the power tube socket to use the 6SN7 octal's. Looking at the data sheet from the stock power tube 6h30pi it appears we are going from a mini glass envelope nine pin with pin nine grounded to an larger octal?

 

We have to remember... Everyone's ears are different. Even with the same tubes, same headphones and same electronics, one person will love them and another will find them so-so. As Mordy reminded us some time ago, tubes are like ice cream. Everyone has a different favorite flavor. And in order to discover your favorite, you might have to try every flavor in the ice cream shop! lol. So I really think you will have to try at least a few to determine your favorite flavor. And when you have found your favorite, it very likely won't be everyone's favorite, especially when you consider that not only do we all have different ears, but also different headphones and different electronics.

 

The adapter you need converts a standard 8-pin octal 6SN7 to a 9-pin 6DJ8 / 6N6 / 6N11 / 6CG7 / 6N30P

 

http://www.ebay.com/itm/1pc-6SN7-6H8C-6N8P-CV1988-B65-VT231-TO-ECC88-6922-6DJ8-6N6-6N11-tube-adapter-/201083508552?


Edited by gibosi - Today at 7:42 pm
post #7993 of 7994
Quote:
Originally Posted by gibosi View Post

This is the view when you look down on the tube while holding it upside down. When working on this adapters, you are essentially looking at the bottom of the C3g, counting pins from left to right, clockwise, and looking at the top of the 6AK5, counting pins right to left, counterclockwise. Keeping these two orientations straight while working on an adapter can be be quite a challenge.

Good luck! smily_headphones1.gif

Indeed, I can see how the mistake could be made!

You have been helpful, gibosi, and i very much appreciate it!!

.
post #7994 of 7994

Hi bb and G,

 

Personally, I don't think that you can find "the best tube" either by price and measured parameters. Let's switch to ice cream - more neutral topic. Most people like ice cream, and I assume that you do as well. How do you know which brand and flavor ice cream you like?

 

Because you tasted it. It's not how much it cost, or what the ingredients are that made you decide that you liked it. You tasted it and said to yourself: I really like this one.

 

And no matter how somebody would explain to you how good this or that one tastes, there is no way of really knowing how it tastes until you take some into your mouth. You get it...

 

It is the same with tubes, but more complicated since they need to be burnt in and be paired with synergistic equipment. (My currently best set of power tubes sounded so bad when they were new that I was ready to write them off and throw them on the dust pile.)

 

What I did was to just look for varied bargain lots and get a bunch of tubes (six, eight, ten etc) and listen. After a while you learn to hear the differences and you learn how to describe them. To my surprise I found other people on this forum that heard the same things I heard so I knew that I wasn't just imagining what I heard. And we were able to agree on groups of top tier tubes and on tube families that were much better than others.

 

If you get a Sylvania made tube (as an example) it doesn't matter if it was rebranded and sold by Radioshack or Sears. It is still a Sylvania tube with the EIA (Electronics Industry Association) number 312 on it. IMHO you do not need to spend big bucks to get excellent sound.

 

The best tube is the one YOU like the best, the one that sounds the best to YOU. Not what the marketing guys tell you is the best. Not the most expensive one. Not the rarest one, and certainly not the oldest one; not the most exotic one, or the one with the most glow or the biggest size etc etc. And everybody knows that British/Dutch/Russian/Japanese/US tubes are the best.....(Personally, I have had the best luck in finding favorite tubes among those that were US made)

 

There is plenty advice on this blog. The best way to find out what you like is to follow some of the recommendations, get the tubes, and listen.

 

Happy tube rolling!

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