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 352

post #5266 of 7566
Quote:
Originally Posted by i luvmusic 2 View Post
 

How do i wire 6SN7 to 12AU7?I have a 9 pin socket and the 8 pin socket and Power Supply all i need is to wire them it's just i have no clue how to do it.

 

I am not sure I understand exactly what you want to do....  Why do you want to wire a 6SN7 to a 12AU7???


Edited by gibosi - 3/7/14 at 3:52pm
post #5267 of 7566
Quote:
Originally Posted by gibosi View Post
 

 

I am not sure I understand exactly what you want to do....  Why do you want to wire a 6SN7 to a 12AU7???

I have a Bravo Audio Ocean Amp that use 12AU7 so i want to try if i can use a 6SN7 with it.THANK YOU!

post #5268 of 7566

Will these work?

6SN7   To    12AU7

1                   2

2                   1

3                   3

4                   7

5                   6

6                   8

7

8

post #5269 of 7566
Quote:
Originally Posted by i luvmusic 2 View Post
 

I have a Bravo Audio Ocean Amp that use 12AU7 so i want to try if i can use a 6SN7 with it.THANK YOU!

 

First, do you know if your 12AU7 is running on 6V heaters? Or 12V heaters?

post #5270 of 7566

If you do not know, then take a voltmeter and measure the voltage between pins 4 and 9. The voltage is likely DC as this amp runs off of a 24V adapter. If no voltage, then it is 12V. Otherwise, you should see 6V. (TrollDragon, please correct me if I am wrong! :)

post #5271 of 7566
Scratch all that...

ILM2 has an external power supply, so all you have to do is match up the Anode / Grid / Cathode of both sides and use the external p/s for your 6V... The next post still applies IMHO.
Edited by TrollDragon - 3/7/14 at 7:22pm
post #5272 of 7566
Personally I would not bother putting Octals on a Bravo Ocean. You probably won't be able to adjust the bias on that tube.
post #5273 of 7566

Oh, I overlooked that you are using an external power supply, so yes, all you have to do is match up the Anode / Grid / Cathode on each side and you are good to go.

 

As to the biasing... I figure you don't know until you try. I have a friend using a 6SN7 in his Crack (modded with a DC PS), which also comes stock with a 12AU7, and it sounds great.

 

Also, I encourage you to try an E80CC, as it is considered an upgrade to the 12AU7. However, the heater current is twice that of the 12AU7, so you will likely have to use your external PS.

post #5274 of 7566

THANK YOU TD and Gibosi i will try!:beerchug:

post #5275 of 7566

Sorry to say that the 6SN7 to 12AU7 for my Bravo did not work properly i double ckecked my wirings still no luck.the LED Power indicator on Bravo turned RED and eventualy shuts off but i can still hear music even the indicator is off and the volume knob turned all the way up just to hear a little music from it but to my surprise no hum/noice at all.:(

post #5276 of 7566
Quote:
Originally Posted by TrollDragon View Post

Personally I would not bother putting Octals on a Bravo Ocean. You probably won't be able to adjust the bias on that tube.
post #5277 of 7566

This is good to know. It is interesting that two 12AU7 amps, the Crack and the Bravo Ocean, react so differently when substituting 6SN7s. I wonder if it is perhaps due to the Ocean having only one amplification stage, whereas the Crack has two stages, a driver and an output?  And I continue to be amazed at the huge variety of tubes we can run in our LDs with nary a problem. :)


Edited by gibosi - 3/8/14 at 8:25am
post #5278 of 7566
Quote:
Originally Posted by gibosi View Post
 

This is good to know. It is interesting that two 12AU7 amps, the Crack and the Bravo Ocean, react so differently when substituting 6SN7s. I wonder if it is perhaps due to the Ocean having only one amplification stage, whereas the Crack has two stages, a driver and an output?  And I continue to be amazed at the huge variety of tubes we can run in our LDs with nary a problem. :)

 

I think it has a lot to do with the way the Bravo provides filament power to the tube, where the Crack has a heater winding directly from the transformer.

 

The Bravo, depending on the version uses a transistor and zener or LM317 regulator to provide the 6.3 VDC heater power... You could probably make enough modifications to the Bravo to allow octals to work but why...

 

It's basically a solid state amp with a little piece of glowing glass on top, to put it a lot nicer than a comment that was made about the Bravo Ocean in another thread which I won't repeat here. ;)

post #5279 of 7566

While I don't want to encourage ILM2 to go to the trouble and expense to procure a simple 6SN7 to 12AU7 adapter, which would therefore use the Ocean's internal heater circuit, I wonder if that would work?

post #5280 of 7566
In theory it should providing the heater current is within limits... I only found user type schematics on line for the Ocean, so I could not be 100% sure that they are not using the a 12V heater. He would still have to measure pins 4&5 to see if there is 12V. There was no board layout to see how pins 4,5 and 9 are configured. ILM2 could take his amp apart and post pictures of the board top and bottom if he wants to. smily_headphones1.gif
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