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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 302

post #4516 of 7355
Quote:
Originally Posted by mordy View Post
 

Hi Artsi,

 

Is the 6N13s similar to the 6080 tube which is used in the LD MK9 ?

Yes 6N13S (6H13C) should be similar to 6080 or 6AS7. LD MK9 uses only one 6SL7 as driver. I have pair of Philips ECG 6080WC USA tubes too.

 

Since this is little dot thread here is size comparison between DIY monster and LD MK II. (furball on the background is my cat)

Originally i chose MK II since it was very small all tube amp. And look at this, now i have this monster on my desk with 5.2kg transformer. And i know that this DIY amp is still very small in two 6AS7/6080 class and it uses push-pull structure.

 

I can use 6SN7 to 6AS7 as powertubes and 6SL7 and 6SN7 as drivers. ECC32 should work too as driver, but they are far too expensive. Power consumption of amp is around 88w with 6080's and 6SN7's. So now i can use my precious 6SU7GTY's. With -73 6N13S's i received four -65 6N8S with square getter. So far they sound very good. I think this model should be the best of non-metal base 6N8S's. http://www.ebay.co.uk/itm/251379277920

post #4517 of 7355

Received a nice assortment of 6CG7 yesterday:

 

Sylvania on the left and an RCA on the right

 

 

And two Tung Sol, both have D-getters, but as you can see there are some differences. The tube with gray plates has a third mica just under the getter and the glass is slightly pinched at the base.

 

 

I spent a little time with the gray Tung Sol last night, and it is a very nice tube. As the 6CG7 is essentially a 6SN7 in a miniature 9-pin format, it has a very spacious sound stage and warm, musical presentation characteristic of these tubes.

 

I paid less than $6 a tube so these are generally very affordable. But again, as these are 600ma tubes, an external heater circuit is recommended. Also of importance to some, these have less gain than the 6DJ8, that is, the volume needs to be turned up a bit higher. 

post #4518 of 7355
Quote:
Originally Posted by Artsi View Post
 

Since this is little dot thread here is size comparison between DIY monster and LD MK II. (furball on the background is my cat)

Originally i chose MK II since it was very small all tube amp. And look at this, now i have this monster on my desk with 5.2kg transformer. And i know that this DIY amp is still very small in two 6AS7/6080 class and it uses push-pull structure.

 

Bravo!

Excellent work, it is really great to see a project start out as a few rolled tubes and turn into a full blown amp!

 

Now you will just need to incorporate 42 of the 6AS7G's with a dozen 6SN7's as drivers like the Atma-Sphere MA-3 does and that is per channel... :D

 

:beerchug:

post #4519 of 7355
Hello again guys!

I am concerned in my move to put 6cg7 to 6sn7 adapters in place of power tubes.
I didn't receive them yet, but I read that I need a seperate power supply to run 6sn7's.
Is that right or does it only apply for driver tube section?
I'm afraid that I can't use the adapters plug and play...
(BTW, do 12ax7 tubes have more potential than yugo 6hm5's?)

And happy new year to you!
Edited by CollectoR13 - 12/31/13 at 10:11am
post #4520 of 7355

 

Received some Octals today Sylvania and Tung-Sol 6SL7GT ,VT-229 , 6SU7GTY and JAN CHS 6SL7 GT. nice warm sounding tube good bass 

Processed By eBay with ImageMagick, z1.1.0. ||B2

Processed By eBay with ImageMagick, z1.1.0. ||B2


Edited by MIKELAP - 12/31/13 at 11:53am
post #4521 of 7355

Hi Mikelap,

 

Agree with you that the 6SL7 tubes are nice and warm sounding with good bass. So much so that I would say that this is the "house" sound of these type of tubes, in addition to a very wide sound stage. This sound quality becomes even more noticeable when you come from 6DJ8 type tubes which are more analytical and colder sounding, although the 6DJ8 tubes have a special place as well with all the wonderful detail and pinpoint imaging. Just two different personalities.

 

Looks like you got some 'oldies but goodies' as well. In the first picture it seems to me that the right Tung Sol tube is from March 1941. The VT designation is an army book keeping designation. From what I read it was in use up til 1945-47 after which the VT designation was discontinued. Therefore a tube that says VT is an assurance that it is quite old.

 

Looks like you will be busy for a while comparing these tubes. Let us know which one sounds the best!

 

Happy tube rolling!

post #4522 of 7355

Hi CollectoR13,

 

The 6CG7 and 6SN7 tubes have a higher current draw than the Little Dot was designed for. As driver tubes they need a separate power supply. Can't remember if this applies to using them as power tubes since the power tubes draw more current than the driver tubes. (I think it applies there as well).

 

Can somebody clarify this?

 

As to the 12AX7 tubes, I only found one that I like, an early 60's Sylvania. The 6DJ8 family seems to be a better choice. In addition, the electric guitar people who use tube amps seem to favor the 12AX7 type tubes, and the prices are high for premium tubes.

 

The 12AX7 variants have more potential than the 6HM5 Yugos. However, if you want plug and play, the Yugo tubes are among the top choices. The other tubes mentioned above are better, but all require modifications.

 

If you look through the posts on this forum, you will find easy ways to add an external power supply. A voltage regulator with a digital readout can be bought for less than $5.00, and you may have a power adapter  lying around the house (inexpensive ones are available). Personally, I am still waiting for my voltage regulator to arrive from China - should be here in a few days.

 

Good luck!

post #4523 of 7355

HI TD,

 

The Atma Sphere MA3 is not that much different than the LD MKIII. The Atma weighs 464 lbs, puts out 500W and costs a little less than $150.000.00. As a bonus, if one of the 54 tubes stop working, you won't notice.:biggrin: 

post #4524 of 7355
Yeah mordy it is quite the beastie!
Built in tube tester as well and you can switch out banks of tubes. biggrin.gif
post #4525 of 7355

 Late delivery today a pair of G.E. JLRV 5814A   very nice sound wide soundstage 3d imaging  like them alot.                                                                                                                                                                                                                                                                                                                                                                                                                Processed By eBay with ImageMagick, z1.1.0. ||B2

post #4526 of 7355

Hi Mikelap,

 

Is this tube similar to a 6.3V 12AU7 tube?

post #4527 of 7355
Quote:
Originally Posted by mordy View Post
 

Hi Mikelap,

 

Is this tube similar to a 6.3V 12AU7 tube?

The 12AU7 and the 5814A are a 12V tube type  i use my 12AX7 adapter to run these.

post #4528 of 7355

I just want to say HAPPY NEW YEAR to all!

post #4529 of 7355
Quote:
Originally Posted by i luvmusic 2 View Post
 

THANK YOU!

Hi MIKELAP,

  Me i asked where did you get the 1mm copper wire for the pins?I can't find them.THANK!

OOPS i just qouted my self.


Edited by i luvmusic 2 - 1/1/14 at 7:26am
post #4530 of 7355
Quote:
Originally Posted by i luvmusic 2 View Post
 

Hi MIKELAP,

  Me i asked where did you get the 1mm copper wire for the pins?I can't find them.THANK!

OOPS i just qouted my self.

In a arts and craft store you could also use big steel paper clips they measure 1mm but you have to measure them to make shure .also if you have coax cable for t.v. i had an old one and the copper cable inside measured 1mm on the other hand the newer cable the copper wire is smaller and if you are wondering how to straitghten a wire heres a video very simple . And a   HAPPY NEW YEAR everybody  .       http://www.youtube.com/watch?v=meZRMNF-6tQ


Edited by MIKELAP - 1/1/14 at 7:51am
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