or Connect
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 370

post #5536 of 10577
Quote:
Originally Posted by gibosi View Post
 

6SN7 update...

 

For some time now, my favorite 6SN7 has been the small-bottle Sylvania 6SN7W. Switching from the HE 300 to the HD 700, this tube continues to impress. :)

 

(In case it is of interest in light of the current discussion on OTL LDs versus the LD 1+ hybrid, the HE 300 is 50 Ohms, 93 dB, and the HD 700 is 150 Ohms, 105 dB, and I notice that I have the volume set almost identically for both on my LD 1+.)

 

I have both the shorty like you love and a black bottom, tall bottle (well taller then the short) GTB and I have to agree they are both beautiful... the GTB has slightly better mids at the expense of some air... I love both for different reasons...

 

Currently I'm running the Gold Arrow 6SN7 (yeah I know I';m home early lol) and its very similar to the short bottle Sylvania... time will tell...

post #5537 of 10577
Quote:
Originally Posted by kvtaco17 View Post
 

I have both the shorty like you love and a black bottom, tall bottle (well taller then the short) GTB and I have to agree they are both beautiful... the GTB has slightly better mids at the expense of some air... I love both for different reasons...

 

Currently I'm running the Gold Arrow 6SN7 (yeah I know I';m home early lol) and its very similar to the short bottle Sylvania... time will tell...

 

As the number of variants produced by Sylvania is large enough to be quite confusing, I should clarify that the tube I am loving is a short-bottle 1944 JAN-CHS-6SN7W. This tube has a single support rod between the two micas and 4 umbrella-like spokes extending downward from the top mica. The short-bottle 6SN7GT and 6SN7GTA, produced in the early 1950's, is a different tube, still excellent, but with slightly dryer mids.

post #5538 of 10577
Quote:
Originally Posted by TrollDragon View Post

You really can't compare OTL to hybrid anyway...

The DT880 have a different sound when driven from the E09K as opposed to my MK IV.

Exactly even at 250 ohms i still prefer it with my hybrid than otl and at 600 ohms otl for me. 

post #5539 of 10577

Is this tube (6AS7,6080 and 6082)compatible with the 6SN7 adapter with external PS for LD?Thanks!

post #5540 of 10577
Quote:
Originally Posted by i luvmusic 2 View Post
 

Is this tube (6AS7,6080 and 6082)compatible with the 6SN7 adapter with external PS for LD?Thanks!

 

Yes, the 6AS7 has the same pin-out as the 6SN7 and could be used in the LD with an external PS. However, this tube draws 2.5 amps of heater current, a bit more than 3 times that of a 6SN7, so a pretty heavy-duty AC adapter is necessary. For example, 15VDC and more than 1.05 amps, or 24VDC and more than .66 amps. And if you want to run two of them as output tubes, you will need to double the current. So yes it will work, but I am guessing the AC adapters many of us are currently using do not provide enough current....

 

Edit: If you search eBay for "laptop power supply" you can find power supplies that can provide enough current.


Edited by gibosi - 3/22/14 at 8:07am
post #5541 of 10577
Quote:
Originally Posted by gibosi View Post
 

 

Yes, the 6AS7 has the same pin-out as the 6SN7 and could be used in the LD with an external PS. However, this tube draws 2.5 amps of heater current, a bit more than 3 times that of a 6SN7, so a pretty heavy-duty AC adapter is necessary. For example, 15VDC and more than 1.05 amps, or 24VDC and more than .66 amps. And if you want to run two of them as output tubes, you will need to double the current. So yes it will work, but I am guessing the AC adapters many of us are currently using do not provide enough current....

 

Edit: If you search eBay for "laptop power supply" you can find power supplies that can provide enough current.

What about using a computer power supply?I have a broken desktop i open it and the PS is 400W 12V 15A.THANK YOU!

Need to use High current regulator.


Edited by i luvmusic 2 - 3/22/14 at 8:21am
post #5542 of 10577
Quote:
Originally Posted by i luvmusic 2 View Post
 

What about using a computer power supply?I have a broken desktop i open it and the PS is 400W 12V 15A.THANK YOU!

 

Yes, a computer power supply has more than enough of current. However, there is still the voltage regulator to consider. My voltage regulator is rated at 2 amps continuous. If yours is similar, it would have to be replaced. This one would likely work:

 

http://www.ebay.com/itm/331064390176?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

post #5543 of 10577
Quote:
Originally Posted by gibosi View Post
 

 

Yes, a computer power supply has more than enough of current. However, there is still the voltage regulator to consider. My voltage regulator is rated at 2 amps continuous. If yours is similar, it would have to be replaced. This one would likely work:

 

http://www.ebay.com/itm/331064390176?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Yes i have that regulator received it 2 days ago and i installed it inside this salvaged electronics box and a scrap piece of aluminum build it last night not done yet but i may need to scrap this and used the Desktop PS instead.THANKS AGAIN Gibosi!:beerchug:

post #5544 of 10577
Quote:
Originally Posted by i luvmusic 2 View Post
 

 

This looks very professional! I think you might have a future building and selling power supplies to Little Dot owners!   :)

post #5545 of 10577
Quote:
Originally Posted by gibosi View Post
 

 

This looks very professional! I think you might have a future building and selling power supplies to Little Dot owners!   :)

THANKS!

   The Desktop PS is Noisy i don't like it the fan is annoying some of my tubes Picked up the noise.:mad:


Edited by i luvmusic 2 - 3/22/14 at 9:52am
post #5546 of 10577

Hi,

 

I just replaced my 2A voltage regulator with the one in the link above which is rated at 5A when applying a little self stick heat sink. The voltage is only displayed by one decimal so I am using a multimeter to set it. Just like the first regulator, turning the adjusting screw for the voltage changes the voltage within the decimal reading, i.e. 8.3V can mean 8.31V or 8.39V. On this voltage regulator you can adjust the readout to make it correspond to a reading from a tester - haven't tried it yet.

 

As mentioned before, the actual voltage at the tube pins on the breadboard can be a little lower than at the voltage regulator output. In my case I am using a 8FQ7 tube as a driver. The voltage regulator LED readout fluctuates between 8.3V and 8.4V (the LED can be shut off if the flickering or light bothers you), The voltage reading is 8.44V at the regulator output terminals, and the breadboard voltage at the tube pins is 8.40V. I don't think that these small variations really matter, but it gives me satisfaction to set it precisely LOL.

 

 

Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?


Edited by mordy - 3/22/14 at 6:59pm
post #5547 of 10577
Quote:
Originally Posted by mordy View Post
 

Hi,

 

I just replaced my 2A voltage regulator with the one in the link above which is rated at 5A when applying a little self stick heat sink. The voltage is only displayed by one decimal so I am using a multimeter to set it. Just like the first regulator, turning the adjusting screw for the voltage changes the voltage within the decimal reading, i.e. 8.3V can mean 8.31V or 8.39V. On this voltage regulator you can adjust the readout to make it correspond to a reading from a tester - haven't tried it yet.

 

As mentioned before, the actual voltage at the tube pins on the breadboard can be a little lower than at the voltage regulator output. In my case I am using a 8FQ7 tube as a driver. The voltage regulator LED readout fluctuates between 8.3V and 8.4V (the LED can be shut off if the flickering or light bothers you), The voltage reading is 8.44V at the regulator output terminals, and the breadboard voltage at the tube pins is 8.40V. I don't think that these small variations really matter, but it gives me satisfaction to set it precisely LOL.

 

 

Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?

What i can say is that in my WA2 i can run as power tubes 6AS7 and 6080's. in post #5540 gibosi says its same pinout


Edited by MIKELAP - 3/22/14 at 7:09pm
post #5548 of 10577
Quote:
Originally Posted by mordy View Post
 

Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?

 

With 2.5 amp heaters, I don't think this tube is typically used as a driver. But yes, it has the same pinout as a 6SN7, and I seem to remember that you are using a laptop power supply, so you have adequate power, and with your new regulator, you are good go.

 

Edit: The 5998, 6080, 6N13S, 6N13P, 6N22P, 6N5P all appear to be similar....


Edited by gibosi - 3/22/14 at 7:43pm
post #5549 of 10577
Quote:
Originally Posted by mordy View Post
 

Hi,

 

Does anybody have experience with a 6AS7 tube as a driver? Can the 6080 and the 6N13S tubes be substituted for the 6AS7 and do they have the same pinout as the 6SN7?

I can use even 6AS7 tubes as driver with my little DIY amp.

With RCA 6AS7G sound is excellent, BUT gain is very low, due to amp factor 2. So with low sensitivity headphones there could be problems to get enough power.

 

I suggest to use 6BL7 with amp factor 15 or 6BX7 amp factor 10. These have same pinout with 6SN7, but 1.5A heater currents. These rare tubes are easily found from USA or Canada EBAY.

post #5550 of 10577
Quote:
Originally Posted by Artsi View Post
 

I suggest to use 6BL7 with amp factor 15 or 6BX7 amp factor 10. These have same pinout with 6SN7, but 1.5A heater currents. These rare tubes are easily found from USA or Canada EBAY.

 

And I believe the LD can handle 1.5A heaters without having to use an external supply, so these may well be worth looking into as power tubes.

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