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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 442

post #6616 of 10486

This waiting time is killing me.....:(

I already have the aluminum plates cut for the crack and no amp yet.

post #6617 of 10486
Quote:
Originally Posted by gibosi View Post
 

 

This evening I tried to mount a sub-miniature in this way, but I failed miserably when it came to putting the wires into the pins. It would seem that I am lacking the necessary dexterity and patience, or perhaps I just didn't hold my tongue the right way or say the correct words. lol :)

 

So as usual, I'm back to easy and ugly again. :)

I've tried to do the same This morning and i give up.

post #6618 of 10486
The key is to have all your wires in a circular pattern. Put the tube wires through the socket top. Then I separated the two halves, brought 3 & 6 forward to plug into 7 & 8 then arranged the 123 side then the 456 side, bending the wire in a circular shape. Line up each wire with the holes and slide the plug up to the socket.

To help with arranging the wires, try flipping over the plug so the pins are up and use that as a form to assist in bending the wires, then turn it over and slide it on. Also a little stick or screwdriver to assist in guiding the wires to the holes might help. Hold the tube inplace with a little masking tape across the top to each side of the socket if it moves around.

Snug your wires up, not too tight and solder, the pins do take quite a bit of heat.

Trim off the excess poking through the pins and bob's your uncle!

It's a bit of a pain that whoever designed the tube didn't follow a standard dual triode pinout.
beerchug.gif
post #6619 of 10486

This evening, I was able to take some time to directly compare my Raytheon 6832 and Sylvania 7963. I found the sound signature of these two tubes to be quite similar with the 6832 being just a tad bit brighter.  In this regard I did not prefer one over the other and consider these tubes about equal.

 

However, in terms of stage and imagery, they were much more different. The 6832 seemingly transports you to a performance space that is somewhat two-dimensional and flat. There is no real sense of depth or height. On the other hand, with the 7963, the performance space is wide, deep and tall. There is a palpable sense of space around the vocalists and instruments, and one can easily pinpoint their locations. For this reason, I believe the Sylvania 7963 is the better tube.

 

It is currently going for around $15 to $20 on eBay, quite a bit more than the 6832, at $3 to $5. And for some, it may not be worth it. After all, the 6832 is a very good tube. On the other hand, I believe the 7963 is in the same league as a pair of C3g's or a Sylvania 6SN7W which typically go for around $70. And so to my mind, the 7963 is a steal for $20. But of course, YMMV. :)

post #6620 of 10486
Quote:
Originally Posted by TrollDragon View Post

The key is to have all your wires in a circular pattern............ 

It's a bit of a pain that whoever designed the tube didn't follow a standard dual triode pinout.
 

 

Thanks for the tips. :)

 

I should confess that I tried this with my 6021 after having uninstalled it from my "easy and ugly" adapter. As the ends of the leads had been wrapped and soldered, I wasn't able to completely restraighten them, and of course, this made the very difficult task of guiding the leads into the pins even more difficult....

 

I might try this again with clean and straight leads when I my 6N16B's arrive. However, these tubes have 9 leads, and I suspect that I will have to guide the leads for the shield and one of the cathodes into the same pin.... again, making a very difficult task just a little more difficult... Or I just might end up installing the 6N16B into a 9-pin socket saver....

 

~~~~~~~~

 

All the American sub-miniature twin triodes have the same pinout. It is my understanding that the pinout was designed in this way to facilitate soldering the tube onto a circuit board, similar to an op amp. But of course, this makes it a pain to install them into the old standard 8-pin and 9-pin adapters.... 

 

But it occurs to me that one could trim the leads a bit and easily insert them into a TO-99 op amp socket. And I have been thinking that it would be slick to have a TO-99 to 8-pin octal adapter, such that we could easily plug and unplug these sub-miniatures. But I haven't quite figured out how to make one....

 

Cheers

post #6621 of 10486

Hi, I'm new to tubes and wondered what pair of tubes Mullard cv4014 would replace, rear or front?

I just got my LD and I've no clue as to which are drivers or power. Are the large ones power and how do you tell what are power or driver in a sellers lists of tubes?

Thanks in advance.

post #6622 of 10486
Yes indeed a semiconductor socket would be perfect, I was going to mount the 6832 in a machined pin DIP 8 socket as I have quite a few from opamp rolling.

This is one from eBay and how it would look, without the bent pin... smily_headphones1.gif


It would be easier to solder wires to a second machine pin socket and epoxy it to the top of your octal socket / plug adapter as you can work from both ends to get the wires aligned.

Then you solder a DIP socket to your new tubes in whichever configuration you need and just plug it in.

This would work perfectly with machine pin TO-99 sockets as well since they have a tube socket type look to them! I'll have to get me some of these from my local RAE electronics distributor.

Pure Genius gibosi, pure genius!
post #6623 of 10486

Hi At,

 

I assume that you have a Little Dot MKIII or IV. These amps have four tubes. The front tubes are the driver tubes, and the rear ones the power tubes.

 

Which model do you have, and what are the other two tubes?

 

The CV4014 is a pentode of the EF91 family. Go to page 77 of this blog and look at the chart there that lists compatible tubes. In addition, download and print out the manual for your amplifier. It is a short read, but very informative. The link is at the bottom of this page:

 

http://www.littledot.net/forum/viewtopic.php?f=9&t=815&sid=d19a88fc5a2b44c2f0c87179030bd08d#p3199

post #6624 of 10486

If you have a breadboard adapter with a 9pin socket, it is easy to build a solderless adapter for the 6832 tube. You need a 9pin socket extender, some 1mm heat shrink tubing, and 0.8mm/18gauge copper wire.

 

Cut the copper wire into small pieces and strip off 1/4" at the end. This becomes a push pin to keep the flexible lead wedged in the socket. Before mounting the leads in the socket extender, thread on appropriate lengths of shrink wrap to insulate the leads from each other.

 

The metal to metal makes for a very good contact area - let's face it; all tube sockets work on this principle.

 

 

 

The heat shrink tubing is not shown in this picture:

 

With this set up you can just pull out the whole assembly with the extender like a regular tube to swap for another tube.

post #6625 of 10486

What about something like this( Rocket Launch Pad:biggrin: )upside down octal socket with terminal block i call it one adapter fits all 8 pin miniature.:atsmile:

post #6626 of 10486

Hi Mordy,

   Have you tried using the 6832 as a Power Tubes?Thank You!

post #6627 of 10486
That is a great adapter as well ILM2!

It just needs a big Red Star and CCCP to set it off, and a Soviet tube of course. biggrin.gif
post #6628 of 10486
Quote:
Originally Posted by TrollDragon View Post

That is a great adapter as well ILM2!

It just needs a big Red Star and CCCP to set it off, and a Soviet tube of course. biggrin.gif

Thanks! And where can i get some of those LOL:ksc75smile: 

post #6629 of 10486

Edited by mordy - 6/22/14 at 8:33pm
post #6630 of 10486
"Hi At,
I assume that you have a Little Dot MKIII or IV. These amps have four tubes. The front tubes are the driver tubes, and the rear ones the power tubes.
Which model do you have, and what are the other two tubes?"


Sorry mordy, I forgot to say my LD is MKII. All the tubes are stock so far since it's new.I was checking my options because I found a Brittish web site for tubes or valves as I call them.
Edited by Audio tumshie - 6/23/14 at 6:16am
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