6N3/6N6 headphone amp using PCB.

[kodabmx]

That got to be for 2 channels..

Yes it is.

Hi kodabmx, I went through the stash of the tubes I have, and I see a lot of 6N6P and 6N2P. Can I use 6N2P instead of 6N3P? Are they considered equivalent? If yes, I would be interested in the board. Thanks

They are not equivalent nor are they the same pinout. 6N3P mu=~33, 6N2P mu=~100.

You can however use these adaptors: 1pc Gold plated ECC88 6922 6DJ8 6N11 6N6P TO 6N3 5670 tube adapter for you amp | eBay

and change the associated cathode resistors from 240R to 1k and it will work albeit with 3 times the gain.

I've made a revision to the board - the cap footprints are all onboard now.

 

[adason]

thanks for the info
i may try just point to point

is your schematics similar to shiit valhalla?

 

[kodabmx]

No idea. Never heard of it.

FWIW 6N3P are like 1$...

 

[adason]

Yes, i know, but i have more than hundred 6N2Ps...

 

[kodabmx]

Fair enough

 

[Francois G]

Yes, i know, but i have more than hundred 6N2Ps...

I do too! (do you need any?) But they (6N2) are 12ax7 like-tubes with 70-100 amplification, apparently not what you need here!

So, get yourself some 6N3P tubes while they are still cheap!

 

[Giordano]

Hello,
I would like to try. Do you have a PCB or would you share gerber for it, so I can get it?
Thanks,
JG

 

[kodabmx]

I have the PCB... I'll send you a DM.

 

[mondogenerator]

Hi,

Just a quick message to thank you - the board arrived today!

 

[kodabmx]

That's good news!

Let me know if you have any questions

 

[Ryssen]

Does the "output cap" have to be as large as 470uF?

 

[kodabmx]

No.
You chose the size based on the load you will drive and the LF response you want.

If you use it as a line stage, it could be as small as 1uF if you're using it to drive a tube amp.
I chose 470uF because they are common and give a good LF response on 32R headphones. If I was making one for just my ATH-R70x (470R) I'd use a 47u film cap only.

Koda

 

[DontHertzMe]

-3dB frequency is = 1/(2πRC). So the lower impedance your headphones are the bigger the capacitor needs to be

 

[kodabmx]

Yup so for 32R headphones it's a crappy -3 of 10Hz but for the 470R headphones I use normally, it drops to 0.7Hz

 

[kodabmx]

Just an FYI for those who asked... I now have a board for 9AJ as input (6N1P 6DJ8 6CG7 etc) instead of 6N3...

 

[Ryssen]

I now have a board for 9AJ as input (6N1P 6DJ8 6CG7 etc) instead of 6N3...

Have you compared the 6CG7 to 6N3?
Whats the difference.

 

[Ryssen]

I am building an amp based on your schema,but I have some projekts before,so it doesnt go so fast...

 

[DontHertzMe]

kodabmx, have you been happy with the high-voltage SMPS? Where did you acquire it?

 

[kodabmx]

I'd say on paper the 6CG7 is more linear being a 6SN7 electrically.

That's a Hammond box, ya?

As far as the SMPS yes i have to say I like them a lot. Google search for "12V 280V" and you'll get a bunch of results including this one: AliExpress.com - Maintaining

 

[Ryssen]

That's a Hammond box, ya?

Yes it´s a hammond.