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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 383

post #5731 of 10504
Quote:
Originally Posted by mab1376 View Post
 

 

Honestly didn't use any, just connected them into the adapter and it stays in there fine.

 

Hi mab....WARNING!... yes, they will work fine like that but (sorry if I'm stating the obvious) the problem could be if ever you decide to lift the tube out - without trying to remove the base from the adapter - and then replace it. You would need to be EXTREMELY careful with the positioning - I found that the tube can sit in the base quite snugly IN ANY POSITION! You would have to mark clearly on the side of the tube the mid-point "pimple" position, and ensure it aligns perfectly with the indent in the base, rather than relying only on "church window" to "church window"...

Better safe than sorry!...

 

Cheers

post #5732 of 10504
Quote:
Originally Posted by hypnos1 View Post
 

 

Hi mab....WARNING!... yes, they will work fine like that but (sorry if I'm stating the obvious) the problem could be if ever you decide to lift the tube out - without trying to remove the base from the adapter - and then replace it. You would need to be EXTREMELY careful with the positioning - I found that the tube can sit in the base quite snugly IN ANY POSITION! You would have to mark clearly on the side of the tube the mid-point "pimple" position, and ensure it aligns perfectly with the indent in the base, rather than relying only on "church window" to "church window"...

Better safe than sorry!...

 

Cheers

 

Yes I lined up the "church window" with the proper hole seemed pretty straight forward. Also i'm aware the evacuation port is extremely sensitive and could cause the tube to lose its vacuum if cracked.

 

I'll probably use some sort of glue for the base in the future when i feel ambitious and deoxit the pins.

 

any suggestions? super glue, gorilla glue, hot glue, caulk?

post #5733 of 10504
Quote:
Originally Posted by mab1376 View Post
 

 

Yes I lined up the "church window" with the proper hole seemed pretty straight forward. Also i'm aware the evacuation port is extremely sensitive and could cause the tube to lose its vacuum if cracked.

 

I'll probably use some sort of glue for the base in the future when i feel ambitious and deoxit the pins.

 

any suggestions? super glue, gorilla glue, hot glue, caulk?

 

Glad you don't seem to be having any trouble regarding positioning, but I would still advise making that visible mark on the side of the tube at the "pimple" position, to be doubly safe...especially if you find it's not so easy to remove the base from the adapter without deforming it too much!

Hopefully you shouldn't find any need for deoxit, with gold-plated pins...but who knows?

 

I personally would go for a 2-part (resin/hardener - rapid cure) adhesive that you mix - in the UK : "Araldite" - which you can apply to the inside rim of the base; which is not too runny; and which you can apply fairly neatly with a very small implement. You don't want it leaking down to the pins - or the evacuation port for that matter (worst case scenario? : it becomes stuck to its 'protector'; the rest of the attachment loosens; you pull/twist the tube and...CRACK!  In case you hadn't noticed already, I'm a natural-born pessimist! But at least it makes me ultra careful...).

I don't know what your version of Araldite is, but I'm sure you get the gist of my meaning...unless anyone else has other/better suggestions?...

post #5734 of 10504

A  few drops of super glue is all you need.

post #5735 of 10504
Quote:
Originally Posted by Nic Rhodes View Post
 

A  few drops of super glue is all you need.


Hi Nic.

 

This might be a little tricky...1. There is a slight gap between the metal base sides and the tube, which really needs to be filled with something thicker than super glue.  2. The 3 gaskets between tube bottom and metal base will also create a slight gap, and thus also need something a bit thicker. Just my own observations...

 

Edit.  ps  I personally have come not to trust so-called "super-glue" in many different situations in the past!...


Edited by hypnos1 - 4/4/14 at 11:37am
post #5736 of 10504

If you need a filler then super glue is not what you need, and I am not a fan of it in general at all, however if you have a wobbly base on say an octal or similar then a few drops will set it hard and is the only place I would ever recommend it but it works well here.

post #5737 of 10504

I received a BRIMAR 13D3 today. As the ECC40 and 6CG7/6FQ7, with a gain of 20, were designed as miniature all-glass replacements for the 6SN7, it appears that the 13D3, with a gain of 32, was designed as a miniature all-glass 9-pin replacement for the ECC32. For some reason, these tubes tend to be somewhat expensive on eBay, around $40 or so, even though I am not aware of any amp that uses them. Eventually my patience was rewarded and I was thrilled to grab this one for $10. :)

 

The pin-out of this tube is identical to the 12AX7, but it requires an external heater PS. In the 6DJ8 setting, disconnect pin 9 (shield) from pin 8, adjust the voltage to 12.6, and go. Or configure your socket to run 12AX7 in 6-volt mode (but be aware that it draws .6amps, hence the need for an external PS), and go.

 

The BRIMAR date code is "4F2", where 4 equals week, F equals month, and 2 equals year, so the year of manufacture could be 1952, 1962 or even 1972. However, with a D-shaped getter, I don't think it is as late as 1972. On the other hand, I am not sure this tube was even available in 1952, so my best guess is 1962.

 

Having just shoved it in my LD, I am pleased to report that it lights up, it's quiet and I hear music. :)

 

post #5738 of 10504
Quote:
Originally Posted by TrollDragon View Post
 


Nice work on the bottom of the LD I+!

 

 

Wobbly tube base... This is from the Antique Radio Forums on how to fix the problem which a lot of them there use.

 

:beerchug:

THANK YOU!i will give that a try when i have time.

 

Quote:
Originally Posted by TrollDragon View Post
 

 

Looking at the bottom of your LD I see the yellow wire seems to join the filament power on both sockets together.

If I can get you to take the cover off of it's transformer and see if there is a label on it, that should tell us how much power the transformer provides for the heaters.

 

Post a picture of the label on the transformer with the Chinese writing and Voltages if you would.

 

Thanks!

Sure i will as soon as i'm done with my other Stuff should have done  that when i had it open for soldering  but yeah i will open it again and see what i can screw around with it again.

 

Quote:
Originally Posted by mordy View Post
 

Hi I luvmusic 2,

 

I bought two octal tubes that the glass moved inside the bakelite bottom. My friend the retired electronics engineer took a little crazyglue and applied it in two-three spots with a little brush that came with the glue (supermarket brand).

 

So far it is holding fine and no problems, and the repair took a minute.

Thank You!i will try that.

post #5739 of 10504

OK so i tried the 6AS7 with the LD MK III i need to turned the volume knob upto 12o'clock way past my listening level which is 9 o'clock to 10 oclock IMO it's very good, smooth i can listen to it in a full volume and not getting fatigue(it's loud) .I Run the amp and 6AS7 for 6hours and their are no barbeque smell or fireworks so that is a good sign for me to continue using this tube but then again i have 8 RCA 6SN7 on the way i prefer the 6AS7 over those 6SN7  i have on hand.I don't have exotic/expensive 6SN7to compare it with all i have are those common variety ex. Marconi GTB, Rogers GTA ,PHILCO GTB, westinghouse GTA, PHILIPS GTB ,GE GTA some Russian 6SN7  and a (Superior Electronics Industries Montreal,CANADA and it's Made in JAPAN).


Edited by i luvmusic 2 - 4/4/14 at 6:07pm
post #5740 of 10504
Quote:
Originally Posted by mab1376 View Post
 

Loving these C3gS tubes!

 

Finally got the shields removed thanks to Hypnos1's guide.

 

I wish i can make my set up clean looking like yours very nice.Me i asked if those Power tubes are the New TUNG-SOL?

post #5741 of 10504
Quote:
Originally Posted by i luvmusic 2 View Post
 

I wish i can make my set up clean looking like yours very nice.Me i asked if those Power tubes are the New TUNG-SOL?

 

Yes they are new production Tung-Sol 6SN7GTB

post #5742 of 10504
Quote:
Originally Posted by mab1376 View Post
 

 

Yes they are new production Tung-Sol 6SN7GTB

Thank You!

post #5743 of 10504

I would like to make a Power Adapter for my MK III i will be using a external power supply(12V 15A and 12A regulator)these adapter will be use with 6SN7 and 6AS7 tubes and the wires are 2ft. long so i'am thinking of using 18awg wire instead of 22awg. would the 18awg  or 22awg wire at 2ft long is big enough to handle the 6AS7 current? Can someone please doubble check my connections below.Thank you!

 

LD MK III (2X)              Adapter(6SN7/6AS7)  (2X)

1 A                               2 A

2 G                              1 G

3 K                               3 K

4 H

5 H

6 A                                5 A

7 G                               4 G

8 K                                6 K

9

post #5744 of 10504
Quote:
Originally Posted by i luvmusic 2 View Post
 

I would like to make a Power Adapter for my MK III i will be using a external power supply(12V 15A and 12A regulator)these adapter will be use with 6SN7 and 6AS7 tubes and the wires are 2ft. long so i'am thinking of using 18awg wire instead of 22awg. would the 18awg  or 22awg wire at 2ft long is big enough to handle the 6AS7 current? Can someone please doubble check my connections below.Thank you!

 

LD MK III (2X)              Adapter(6SN7/6AS7)  (2X)

1 A                               2 A

2 G                              1 G

3 K                               3 K

4 H

5 H

6 A                                5 A

7 G                               4 G

8 K                                6 K

9

 

The connections look good to me. As to the adequacy of 18awg or 22awg, someone else will have to weigh in.....

post #5745 of 10504
According to the chart #18 will handle 16A. You could probably get away with a 20 or 22 AWG but if your power supply is fused at 12 or 15A, anything lower than 18 would glow red and burn before the fuse blew.

So I would use the 18AWG just incase you ever had a short it would pop the fuse in the power supply.

If the powersupplys fuse is replaceable, you could put an 6 or 8A in place of what is there and use lower gauge wire.

18 is not that bad to work with so go with it, safety first.

AWG wire chart.
www.powerstream.com/Wire_Size.htm
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