Single ended headphone amplifier

[dsavitsk]

If you are looking for Grado specific transformer coupled amps, try these from my website:

This one is almost the exact same amp as audiodesign's
http://www.ecp.cc/semha.html

And this is the improvement:
http://www.ecp.cc/SSS.html

These are parafeed designs:
http://www.ecp.cc/less-pressivo-plus-plus.html
http://www.ecp.cc/less-pressivo-plus.html


and this one I posted to Headwize two days ago:
http://headwize.com/ubb/showpage.php?fnum=3&tid=7627

Also, member Kevinkr has a WE417 - 71a design floating around that is worth looking into.

[audiodesign]

This could be the schematic.

An Rout about 14ohm is not the top to drive 32ohm but there is no better design using a single tube on single ended design.

The D3A is the unique tube with a very low anodic resistance and enough voltage gain.

[athos56]

Your time is appreciated! I'll try this out.

dsavitsk I checked out your page as well. There is always so many choices!

[athos56]

Maybe feed it with a pair of 0B3's for 180v. I've been looking for a reason to use some glow tubes...

[Cauhtemoc]

Originally posted by audiodesign
This could be the schematic.

An Rout about 14ohm is not the top to drive 32ohm but there is no better design using a single tube on single ended design.

The D3A is the unique tube with a very low anodic resistance and enough voltage gain.

4 Vrms into Grados is unbelievably loud, even 1 Vrms would be enough. If you want a better transformer you would probably have to go for something like an LL1620. Not exactly cheap, but pretty much as good as it gets.

[athos56]

I saw some NOS d3a's so I picked them up. I figured I could use the same supply as in my Tube buffer which put out ~250v. Put a pair of 0B3's bypassed with a .o1uf cap after the last RC for 180v and a nice glow (i think the load resistor would have to be 1k?) Should fit nicely into the same size case as my buffer as well. Two questions.

If 4 Vrms is too much is there a simple way to bring it down a bit?

Could I use my buffer for the volume control or should I put a pot in it and run it straight from the source?