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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 224

post #3346 of 8784

The Haltron 6CS6's are running now with the switches in 2-7, the sound is so much better that the NEC 6AV6's and the bass is back!

I am going to try 1-7 / NS / 2-7 on my switches and see which one I like the best.

:beerchug:

post #3347 of 8784
Quote:
Originally Posted by gibosi View Post
 

 

Hope this explanation will help a bit....

 

When we insert a 9-pin 6DJ8 or 6BQ7A into a 7-pin adaptor, we have the following:

 

Tube pin assignment  -> unmodified adapter  -> Little Dot pin-hole assignment

 

Tube pin 8 (cathode) -> pin-hole 7 (screen/suppressor grid)
Tube pin 7 (grid)  -> pin-hole 6 (screen/suppressor grid)
Tube pin 6 (plate) -> pin-hole 5 (plate)
Tube pin 5 (heater) -> pin-hole 4 (heater)
Tube pin 4 (heater) -> pin-hole 3 (heater)

 

We are fortunate that tube pins 4, 5 and 6 line up perfectly. However, we are not so lucky with tube pins 8 and 7. The Little Dot assigns the grid to pin-hole 1, not pin-hole 6; and the cathode to pin-hole 2, not pin-hole 7.

 

So we modify the adapter. We connect tube pin 8 (adapter pin 7) to adapter pin 2 to reroute the cathode to pin-hole 2, and tube pin 7 (adapter pin 6) to adapter pin 1 to reroute the grid to pin-hole 1.

 

Now that adapter pins 2 and 7 are connected and pins 6 and 1 are connected, we do not want pins 6 and 7 to extend out of the bottom of the adapter and into pin-holes 6 and 7 in the Little Dot socket. So we cut them a bit short. When you look at the bottom of the adapter, you will see only 5 pins, as the other two have been shortened.

 

Hope this helps. :)

 

PS: Very frankly, it was quite a struggle to put my adapters back to together after modification, but everything is working perfect. Therefore, I am very reluctant to take them apart in order to take pictures as I don't want to risk breaking them somehow. (>_<)

 

Come on gibosi take them apart please :evil: lol just kidding i manage to put them back together once in less than 5 minutes tried again later coulndt do it this is a job for the morning when i have patience thanks alot for the explanation ill assimilate that tonight and think about it tomorrow .ill take the pictures when i do the mod and post them after waiting for my tubes and my third hand only got two at the moment not enough .

post #3348 of 8784
Quote:
Originally Posted by mordy View Post

BTW: Is that price of $50 in USD?

 

I guess it's Taiwanese money.

post #3349 of 8784
Quote:
Originally Posted by TrollDragon View Post
 

I have converted the table on page 77 to Excel & Open Office formats if anyone wants the table locally on their machine.

I will try to keep the files updated when future table changes occur.

 

Excel XLS format.

 

Open Office ODS format.

:beerchug: 

 

Good idea to convert the table.

 

Since I put a little bit of effort into this, a PM instead of hostile takeover would have been nice, especially considering there aren't even any new types of tubes.

post #3350 of 8784
Quote:
Originally Posted by TrollDragon View Post
 

I have converted the table on page 77 to Excel & Open Office formats if anyone wants the table locally on their machine.

I will try to keep the files updated when future table changes occur.

 

Excel XLS format.

 

Open Office ODS format.

:beerchug: 

 

how about opening a google doc IIRC it has live update so once you update everyone can see it without the need to keep on downloading a new file.

post #3351 of 8784
Quote:
Originally Posted by Acapella11 View Post
 

 

Good idea to convert the table.

 

Since I put a little bit of effort into this, a PM instead of hostile takeover would have been nice, especially considering there aren't even any new types of tubes.

 

Sorry, I presumed it would be handy converting the table and I really should have asked first, it was late when I created the post and could have worded it better with proper credit given. I am by no means taking over all your excellent hard work and putting the links to the files in my signature was an easy reference for those wanted them. I have since removed the sig links and I will also remove the dropbox files if you so wish.

 

I sincerely didn't mean to step on any toes here.

My most humble apologies.

post #3352 of 8784

Hi Oskari,

 

You are right, Taiwanese dollars. $50 TWN looks scary, but it is only USD $1.70

post #3353 of 8784
Quote:
Originally Posted by TrollDragon View Post
 

 

Sorry, I presumed it would be handy converting the table and I really should have asked first, it was late when I created the post and could have worded it better with proper credit given. I am by no means taking over all your excellent hard work and putting the links to the files in my signature was an easy reference for those wanted them. I have since removed the sig links and I will also remove the dropbox files if you so wish.

 

I sincerely didn't mean to step on any toes here.

My most humble apologies.

 

Don't remove the files. I think it's good if they are accessible for everyone. I would have appreciated if you would have asked, this is nice just out of respect for the work. I might have not even minded. 

 

I am not as active in the thread anymore anyways and I support progress. If you fancy improving it, why not. As you can see in the table, I have tried to keep members acknowledged for their findings. That's just how I work. So, what I would appreciate is to include a note / acknowledgement of my posting on page 77.

Keep the the good spirit.

post #3354 of 8784
Quote:
Originally Posted by Acapella11 View Post
 

 

Don't remove the files. I think it's good if they are accessible for everyone. I would have appreciated if you would have asked, this is nice just out of respect for the work. I might have not even minded. 

 

I am not as active in the thread anymore anyways and I support progress. If you fancy improving it, why not. As you can see in the table, I have tried to keep members acknowledged for their findings. That's just how I work. So, what I would appreciate is to include a note / acknowledgement of my posting on page 77.

Keep the the good spirit.

 

I will put the well deserved credit at the top of the files and a link to the table on page 77 which I should have done when I converted the table.

This is why I shouldn't do things when I should be in bed. :smile:

post #3355 of 8784

GE 6AV6 came in today! Trimmed some pins and threw the lil amp in EF92, burning in as I type!

post #3356 of 8784
Quote:
Originally Posted by gibosi View Post
 

 

I had a chance to listen to the HD800 (300 Ohms) recently, and like you, I thought it sounded fine on my LD1+. And I have been I wondering how much of this is a direct function of the installed op amp? Or is it more complicated? For example, the technical info for the LME49990 op amp explicitly states that it "Easily Drives 600Ω Load." I didn't try the HD 800 with the stock op amp, so I have no idea if that would have made any difference....

 

Unfortunately, the best I DAC I have used with the LD1+ is the Schiit Modi, so can't add anything....

tried the stock op amp and it sounded congested and weird the LME 49990 and OPA627AP sound good... volume was ok with all 3...


Edited by kvtaco17 - 10/7/13 at 3:18pm
post #3357 of 8784
Quote:
Originally Posted by gibosi View Post
 

 

As long as you use stranded wire, everything will be fine. I was shoving tubes in and out of my LD like a mad man and using solid core wire. It takes time and a lot of rolling to do any real damage. So by all means, use 26 gauge, or smaller stranded wire, and enjoy them.

 

Oh, there is very little current passing through this wire, measured in milliamps at most. A very tiny wire is more than sufficient.

 

I have two comments regarding your suggested alternative. First, it is very difficult to solder wire to tube pins. You want the surface of the tube pin right up against the glass base to be very clean and shiny. You will likely have to use sandpaper or a sharp knife to get down to shiny metal. Otherwise, the solder will not adhere properly. And second, if you use a "slightly thicker wire", the thickness of the wire will prevent the tube from sitting properly in the socket and the pins will not make good contact.

 

That said, if you are willing to put in the necessary time and effort, soldering a wire is the best solution, IMHO. And if you are willing, I would recommend 30 gauge solid core wire.

 

 

I did not try to solder this connection, but as you can see, 30 gauge wire is tiny enough not to cause any problems when the tube is inserted into the socket.

 

But again, they have just arrived! Don't deny yourself!  Use a little piece of small stranded wire and enjoy. :)

 

And then, if you end up loving these TS 6485, it will be worth the extra time and effort to figure out how to get a good soldered wire connection.

 

So you simply wrap solder wire around the pins and solder them on?

By doing this you are strapping the pins right.

post #3358 of 8784
Quote:
Originally Posted by Sony Slave View Post
 

So you simply wrap solder wire around the pins and solder them on?

By doing this you are strapping the pins right.

 

Yes.

 

Obviously, there are two ways to strap. You can strap the tube itself. Or you can strap in the socket.

 

Soldering wire to the pins modifies the tube itself and is a very durable and permanent mod. Dropping 26 gauge, or smaller, stranded wire into the socket pin holes before inserting the tube is very temporary. Either way is fine. It is entirely up to you.   

post #3359 of 8784
Quote:
Originally Posted by gibosi View Post
 

 

Yes.

 

Obviously, there are two ways to strap. You can strap the tube itself. Or you can strap in the socket.

 

Soldering wire to the pins modifies the tube itself and is a very durable and permanent mod. Dropping 26 gauge, or smaller, stranded wire into the socket pin holes before inserting the tube is very temporary. Either way is fine. It is entirely up to you.   

 

ok. I then.

 

I have an off topic question, does the Little dot 1+ sound worse than the MKiii and iv? 

 

Even though I have low impedance cans (SRH840's), i'm just wondering if I am missing out on anything.

post #3360 of 8784
Quote:
Originally Posted by Sony Slave View Post
 

 

ok. I then.

 

I have an off topic question, does the Little dot 1+ sound worse than the MKiii and iv? 

 

Even though I have low impedance cans (SRH840's), i'm just wondering if I am missing out on anything.

 

The Mk iii and iv are not really suitable for low impedance cans (see their output specifications on the Little Dot site) as they put out less power as the impedance load decreases.  Plus those amps have a high output impedance which does not play nice with low impedance cans (poor damping).  The I+ is much more suitable for low impedance headphones.

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