Little Dot Tube Amps: Vacuum Tube Rolling Guide
May 25, 2014 at 12:55 PM Post #6,256 of 13,434
  I know that there are people on the blog that tried various sub miniature tubes in the past. One such post came from Critical Bill, maybe in 2009, but right now I cannot find his post. Would appreciate it if somebody has information, as well as information on comparisons between different dual triode sub minis.

 
His handle is Ctritical Bill.
 
May 25, 2014 at 3:44 PM Post #6,257 of 13,434
  Hi I lovemusic2,
 
Glad you like the 6832 tubes. As with everything else, the sound depends on the associated equipment, and in my case I found the 6832s very good as power tubes, but ultimately lacking in the bass slam and impact.
 
I am happily using one as a driver, but I went back to my RCA 6SN7GTB tubes as power tubes. In the future I would like to try a pair of 6080 tubes as power tubes, but these require external power supplies since they draw 2.5A each. Once all the parts come in I am going to try and see how it sounds.
 
I know that there are people on the blog that tried various sub miniature tubes in the past. One such post came from Critical Bill, maybe in 2009, but right now I cannot find his post. Would appreciate it if somebody has information, as well as information on comparisons between different dual triode sub minis.
 
Somehow the sub miniature tubes do not have the visual appeal of the Coke Bottle tubes, but looks isn't everything!
 
CU6LHikzfy5SYSQC_K2oJc0VhoHCZ8sh1PfkZrOJoLOcf0VtAtfl7-hBP9EMGhlo7_BOZpHMEESiXa5AS6QwBcOecALoU-BhWuV2_rYEb2bKiYdpoa_b_C_weiU0eu7iJUu6Ns6L=s0-d-e1-ft

 
 
These are mighty minis, and really the pinnacle of vacuum tube technology. For those of you who like to travel with the LD amp, they are good for 80,000 feet altitude (commercial air planes fly under 40,000 feet). They can withstand a 500G impact, and 2,5G vibration, as well as nuclear radiation. The amplification factor is 40.
 
Which one is the best sub miniature tube for the LD MKIII?

 
Hi mordy.
 
Your and gibosi's wee wonders certainly sound interesting...would have been SO much easier to adapt than the C3G, viz the DIY version! And also, it seems, would have been a lot cheaper, lol!
 
Ah well, another of life's "if only's". Mind you, I think they would look a little 'strange' perched in front of the giants...and I am into aesthetics, as w
 
ell as sound
tongue.gif
.
 
 
As an update to my previous post, re the E88CCs driving the "coke bottles", it appears I have been granted a reprieve...after their initial "wow" factor, the C3GS still reigns supreme and I have no regrets spending out on them - apart from the price some have been going for! (I was looking for weeks and never had that kind of luck
frown.gif
.  And am back in love with them even more now I have finished silver wire adapter #2...there is no doubt in my mind that pure silver in as much of the signal path as possible does bring extra benefits...most notably in the treble area - more 'sparkle', and decay to the notes...lovely...
 
I cannot wait for your comments when you get those 6080s in the hot seat...you are in for one hell of a surprise mordy - if mine is anything to go by...and wouldn't it be great if someone out Far East did make an adapter with the 2 power leads exiting the back...makes for a nice , neat package... :
 
Ah well, the picture was supposed to end up here, not above...but didn't! Sometimes this site does some VERY strange things lol! Still, am very grateful for it nonetheless.
 
May 25, 2014 at 4:50 PM Post #6,259 of 13,434
  Hi I lovemusic2,
 
Glad you like the 6832 tubes. As with everything else, the sound depends on the associated equipment, and in my case I found the 6832s very good as power tubes, but ultimately lacking in the bass slam and impact.
 
I am happily using one as a driver, but I went back to my RCA 6SN7GTB tubes as power tubes. In the future I would like to try a pair of 6080 tubes as power tubes, but these require external power supplies since they draw 2.5A each. Once all the parts come in I am going to try and see how it sounds.
 
I know that there are people on the blog that tried various sub miniature tubes in the past. One such post came from Critical Bill, maybe in 2009, but right now I cannot find his post. Would appreciate it if somebody has information, as well as information on comparisons between different dual triode sub minis.
 
Somehow the sub miniature tubes do not have the visual appeal of the Coke Bottle tubes, but looks isn't everything!
 
CU6LHikzfy5SYSQC_K2oJc0VhoHCZ8sh1PfkZrOJoLOcf0VtAtfl7-hBP9EMGhlo7_BOZpHMEESiXa5AS6QwBcOecALoU-BhWuV2_rYEb2bKiYdpoa_b_C_weiU0eu7iJUu6Ns6L=s0-d-e1-ft

 
 
These are mighty minis, and really the pinnacle of vacuum tube technology. For those of you who like to travel with the LD amp, they are good for 80,000 feet altitude (commercial air planes fly under 40,000 feet). They can withstand a 500G impact, and 2,5G vibration, as well as nuclear radiation. The amplification factor is 40.
 
Which one is the best sub miniature tube for the LD MKIII?

Hi Mordy,
      The 6080 is identical to 6AS7 i beleived by using 2 as power tubes for MK III(which i have) IMO there is nothing special about it except creating a lot of heat for the MK III i'am not comfortable using it as a power tubes on my MK III it gets  too hot.As much i love to push my amp to it's limit i would not bother using it with my amp although it works.Enjoy and Good luck with your 6080!
 
May 25, 2014 at 6:08 PM Post #6,263 of 13,434
        The 6080 is identical to 6AS7 i beleived by using 2 as power tubes for MK III(which i have) IMO there is nothing special about it except creating a lot of heat for the MK III i'am not comfortable using it as a power tubes on my MK III it gets  too hot.As much i love to push my amp to it's limit i would not bother using it with my amp although it works.Enjoy and Good luck with your 6080!

 
Hypnos1 has been running 6AS7's in his MK IV and his most recent temperature measurements on a critical resistor don't seem overly hot: 
 
"36C after 1 hour, and 39C after 4.5 hrs"
 
Have you taken similar measurements in your MK III?
 
May 25, 2014 at 6:15 PM Post #6,265 of 13,434
   
Hypnos1 has been running 6AS7's in his MK IV and his most recent temperature measurements on a critical resistor don't seem overly hot: 
 
"36C after 1 hour, and 39C after 4.5 hrs"
 
Have you taken similar measurements in your MK III?

No i did not but IMO when touching the case it's too hot to the touch hotter than usual.I don't know about MK IV if they have same resistor rating with MK III and  i'm not willing to open up my MK III again LOL.
 
May 25, 2014 at 6:35 PM Post #6,267 of 13,434
 
  Do you think you should use these if you choose to go sub mini?

link 9-pin breadboard / prototype tube socket for DIY experimenting @ ebay

Yes you can! see gibosi's and Mordy's post or you can refer to mine just used the terminal block as long as the tube leads are long enough to reach those terminal blocks.

I guess then what I am asking that is that prototype board the right size to plug a sub meanie tube into straightaway without doing what you are showing above?
 
P.S. after looking at your picture I think the one that's right for the minis is linked and pictured below.
 
7-pin mini breadboard / prototype tube socket for DIY experimenting

 
May 25, 2014 at 6:42 PM Post #6,269 of 13,434
Or it could be less bass because of my 6AS7 (mine is 6H13C)Brand/Manufacturer maybe it depends on tubes brand/manufacturer i could be wrong.
NOTE: I'am not trying to discourage some of you guys to used 6AS7 as power tubes it's just my opinion.
 

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