Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide
New Posts  All Forums:Forum Nav:

Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 374

post #5596 of 7217
Quote:
Originally Posted by mordy View Post
 

Hi Hypnos1,

 

I am sure the C3g tubes are better. Thing is, I am happy with the 6BX7 tube. I am going to try some similar variants if I can get a good price.

 

As you suggested I am burning in the tube. Don't know how much an effect the extender/socket saver adapters have on sound, but they look cheaply made and are only supposed to last 200 times for changing the tubes . They are not deep enough to completely insert the octal adapter 9 pin bottom pins, and there is is a 2 mm gap between the adapters. Maybe good for ventilation LOL?

 

 

 

Thanks, mordy, for encouragement/solace(!) re the C3GS tubes - I'm sure mab1376 is equally comforted!!...Let's not forget CollectoR13, who has also joined the club (and was very impressed with them...).

 

As for adapters AND extenders, I can't help feeling they must degrade the signal somewhat, which is why I persevered with making my own, using solid silver wire - acting also as the pins. But I can understand a reluctance to shy away from the task!

 

Good luck with the other 'variants'...

post #5597 of 7217
Quote:
Originally Posted by mab1376 View Post
 

 

Those are the adapters i commissioned, they just put it up for other people to purchase. they will be using hypnos1's pinout he posted a while back.

 

They are pricy indeed, but they are the first built and handmade with skills i don't posses so i feel its worth it if the c3gs is as good as hypnos1 says. Plus i can finally get rid of the spider web of wires on my unit right now. :atsmile:

 

Hi mab.

 

Very resourceful of you to commission those adapters...certainly a lot easier than making your own! (But OF COURSE you possess the required skills...you just haven't flexed those particular muscles yet! - I myself am by no means an electronics engineer, and with just a little practice - plus a bit of research on Google/youtube - it's amazing what you can achieve...with a modicum of care and patience thrown in, of course!).

 

BTW...I hope you instructed them to link C3g pins 2 and 7 within the adapter?...

 

I do hope they make a good job of them - I can't wait to hear your impressions...

post #5598 of 7217

Broken ECC40

 

For those who do not remember, the ECC40 was a Philips' design to replace the 6SN7GT with a miniature all-glass tube having reduced microphonics. I was listening to one of my favorites, made in Eindhoven in 1951, when suddenly the music faded and the filaments went dark. And then when I tried to remove it from the socket, the entire glass bottle broke off from the base... :(

 

Anyway, I thought some might be interested in seeing the internal structure in some detail. It is a very well-built tube, with thick micas, a number of vertical reinforcement rods and some curious structures, pieces of sheet metal attached to copper posts, located above the top mica. Some call these structures, "flags", but I can only guess at their intended purpose.

 

 

post #5599 of 7217
So quick update now for the C3GS.
I put around 50hrs on them now and they changed kind of noticable, much more rounded and dynamic.
All I have to say is: endgame.
As hypnos said in his first posts about these tubes, they are some of the best to put in a little dot.
I think they are totally neutral but with a clarity I never imagined to get from the little dot, as it will never be the most high end amp, but wasn't supposed to be.
What you get is a tube that doesn't color much and is absolutely true to the record, in combination with my sylvania 6sn7gt there is some serious punch and dynamic if the record delivers.
That is also one of my main problems, bad albums sound bad.
But I can live with it, as it is not like you never can't listen cause it sounds so bad, but rather like this: yep, could be better. (changing album) oh, yeah, this is how it goes!.
My setup is now complete, it was a good decision to build these adapter, although building the adapters + price of the tubes was a little expensive, but however... its like the whole hifi hobby: pricey.
In exchange you are taking the little dot to another level, clearly no comparison to other 6ak5 and 6n6p 's, my voskhods got totally destroyed by the siemens.
But reading the positive experiences about the shuguang 6sn7, I am tempted to try better 6sn7's....
Must..... Resist.... lol
post #5600 of 7217

Hi G,

 

Here is a more elaborate eulogy of an expired tube:

 

http://www.jacmusic.com/images/amps/Kees-Soeters/Kees-soeters-kistje-open.jpe

 

ANNOUNCEMENT

A very regretful message from Kees has reached us.

One of his Arcturus 227 tubes has passed away. It died quietly and unexpectedly from a broken filament,  at the age of 79 years.

ARCTURUS Tube 227
Born 1927
Died February 2006

 

SonoraRA-1.jpg

 

And speaking of old tubes, I couldn't resist showing pictures of this 6C21 tube:

 

Image

 

Image

Some specs:

Base Sidecontact and top contact
Filament Vf 8.2 Volts / If 17 Ampere / Direct /
Description Special version of 1000T transmitting triode, intended as high-voltage radar pulse modulator. Capable of handling pulses of 15A at 30KV, with grid driven from -1000V cutoff to 1500V.
post #5601 of 7217
Quote:
Originally Posted by hypnos1 View Post
 

 

Hi mab.

 

Very resourceful of you to commission those adapters...certainly a lot easier than making your own! (But OF COURSE you possess the required skills...you just haven't flexed those particular muscles yet! - I myself am by no means an electronics engineer, and with just a little practice - plus a bit of research on Google/youtube - it's amazing what you can achieve...with a modicum of care and patience thrown in, of course!).

 

BTW...I hope you instructed them to link C3g pins 2 and 7 within the adapter?...

 

I do hope they make a good job of them - I can't wait to hear your impressions...

This is the pin mapping i used:

 

cg3 6ak5
   
1 3
2 7
3 5
4 6
5 2
6 1
7 7
8 4

 

Or the other way around to make it easier to read:

 

6ak5 c3g
1 6
2 5
3 1
4 8
5 3
6 4
7 2,7

Edited by mab1376 - 3/26/14 at 11:19am
post #5602 of 7217
Quote:
Originally Posted by gibosi View Post
 

Anyway, I thought some might be interested in seeing the internal structure in some detail. It is a very well-built tube, with thick micas, a number of vertical reinforcement rods and some curious structures, pieces of sheet metal attached to copper posts, located above the top mica. Some call these structures, "flags", but I can only guess at their intended purpose.

 

Sorry about your loss.

 

That is interesting indeed. I believe those are heat radiators for cooling the grid wires. They are fixed to grid posts, aren't they?

post #5603 of 7217
Quote:
Originally Posted by CollectoR13 View Post

So quick update now for the C3GS.
I put around 50hrs on them now and they changed kind of noticable, much more rounded and dynamic.
All I have to say is: endgame.
As hypnos said in his first posts about these tubes, they are some of the best to put in a little dot.
I think they are totally neutral but with a clarity I never imagined to get from the little dot, as it will never be the most high end amp, but wasn't supposed to be.
What you get is a tube that doesn't color much and is absolutely true to the record, in combination with my sylvania 6sn7gt there is some serious punch and dynamic if the record delivers.
That is also one of my main problems, bad albums sound bad.
But I can live with it, as it is not like you never can't listen cause it sounds so bad, but rather like this: yep, could be better. (changing album) oh, yeah, this is how it goes!.
My setup is now complete, it was a good decision to build these adapter, although building the adapters + price of the tubes was a little expensive, but however... its like the whole hifi hobby: pricey.
In exchange you are taking the little dot to another level, clearly no comparison to other 6ak5 and 6n6p 's, my voskhods got totally destroyed by the siemens.
But reading the positive experiences about the shuguang 6sn7, I am tempted to try better 6sn7's....
Must..... Resist.... lol

 

Hi CR13.

 

Yep...about 50hrs make these babies really shine - so glad you echo my findings. You summed things up nicely : that quality of 'clarity', along with what I term 'clean' sound is what I find most attractive about them (especially as they do everything else so well...). And yes again, poor recordings are shown no mercy...which does not bother me at all!! And as for hi-res recordings, I am totally blown away (am sure the Psvane CV181-T MKII powers come into their own here especially...give out some hints come birthday or Christmas time! - I don't think the standard Shuguang 6SN7s would 'cut the mustard', but probably their CV181-z would be good). I plumped for the Psvanes as I like how they seemed to genuinely build on the Shuguang origins, and I do not regret one iota splurging out on them - plus, I love how they look!!

 

It will be interesting to see how the Sylvania 6SN7GT-VT231s compare - I believe they're supposed to surpass the standard GTs?

 

We await mab1376's assessment of the C3GSs with eager anticipation!...

 

Glad you are enjoying the results of your time, effort and expense...HAPPY LISTENING...

 

 

 

Quote:
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   
   

Edited by hypnos1 - 3/26/14 at 12:54pm
post #5604 of 7217
Quote:
Originally Posted by mab1376 View Post
 

This is the pin mapping i used:

 

cg3 6ak5
   
1 3
2 7
3 5
4 6
5 2
6 1
7 7
8 4

 

Or the other way around to make it easier to read:

 

6ak5 c3g
1 6
2 5
3 1
4 8
5 3
6 4
7 2,7

 

Good, good, mab...everything looks fine - now just the wait!...

 

Patience, mon ami

post #5605 of 7217
Quote:
Originally Posted by hypnos1 View Post
 

 

Good, good, mab...everything looks fine - now just the wait!...

 

Patience, mon ami

 

Tubes are almost here from Germany, adapters are coming from China so who knows.

 

Only time will tell.

post #5606 of 7217
Quote:
Originally Posted by Oskari View Post
 

Sorry about your loss.

 

That is interesting indeed. I believe those are heat radiators for cooling the grid wires. They are fixed to grid posts, aren't they?

 

Fortunately, I have one more of these Eindhoven #5 tubes, so all is not lost. But for sure, I will be keeping my eye open for another so that I always have a backup. :)

 

And I am pretty sure these are copper grid posts. Looking through the holes in the plates, I can see a fine wire wrapped around these copper posts, and I assume that that is the grid wire I am seeing...... 

post #5607 of 7217
Quote:
Originally Posted by gibosi View Post
 

Looking through the holes in the plates, I can see a fine wire wrapped around these copper posts, and I assume that that is the grid wire I am seeing...... 

 

Absolutely.

post #5608 of 7217
Quote:
Originally Posted by mordy View Post
 

Here is a more elaborate eulogy of an expired tube:

 

Lol at the coffin. :D

post #5609 of 7217
Quote:
Originally Posted by mordy View Post
 

Hi i luvmusic 2,

 

The 6SN7 tubes are just plug and play with an adapter (you need two of them):

 

http://www.ebay.com/itm/221065459067?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

If the decorative ring prevents the adapters from getting seated in the sockets you need two socket savers to use as extenders. The adapters may be too wide to fit inside the diameter of the decorative ring and the pins do not reach into the sockets:

 

http://www.ebay.com/itm/2PCS-9-PIN-vaccum-TUBE-SOCKET-SAVER-FOR-12AX7-12AU7-ECC82-ECC83-tube-audio-amps-/251350602537?pt=Vintage_Electronics_R2&hash=item3a85a9d329

 

 

The 6AS7 tubes are the same pinout but they draw more current than the LD amp can handle. It is therefore imperative that you have an external power supply that supplies both tubes with the proper voltage and amperage; in this case 2.5A.  I do not have experience with this setup. You need some kind of adapter that allows you to connect the heaters of each tube separately to the appropriate voltage regulator and power supply.

Thank you for the links i have the 9 pin socket saver.I'am going to make my own. my idea is to  solder some wires on the socket tabs and at the end of the wires(Stranded wire) solder 18AWG solid copper wire and it's done i've done this with the 12AU7 adapter just plug the 18 AWG wire in the socket .Regarding the Power Supply i got plenty of current on my PS 15A(Desktop PS) and 12A regulator so no worries there.Again Thank You! 

 

Quote:
Originally Posted by CollectoR13 View Post


Here is my wiring diagram I used for my adapters, full tutorial coming soon!

So since i'm using a Enternal Power Supply i don't need to connect 6AS7 pin 7 and 8 to 6N6p pin 4 and 5 and 6N6p pin 9 no connection just to clarify before i create a fireworks.THANK YOU!

post #5610 of 7217
Quote:
Originally Posted by i luvmusic 2 View Post
 

So since i'm using a Enternal Power Supply i don't need to connect 6AS7 pin 7 and 8 to 6N6p pin 4 and 5 and 6N6p pin 9 no connection just to clarify before i create a fireworks.THANK YOU!

 

As you are going to use an external heater PS to provide power to the 6AS7, pins 7 and 8, you should definitely leave pins 4, 5 and 9 disconnected in the socket.

 

Cheers :)

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › Little Dot Tube Amps: Vacuum Tube Rolling Guide