Any transformer coupled Push-Pull headphone amp designs?

Something like a 6n6p, 5687, 7119, ECC99, etc works well in this sort of setup. If you have a balanced source, then you don't need a splitter. If you don't, then, you can self-spit the signal, or use another stage as a splitter, or use an input transformer (edcor makes some that cost ~$10 each.)

I'm powering my HE-5 orthos from a simple 3 stage  push-pull amp based on triode connected 4P1l directly heated pentodes. First two stages are done by a 6922 configured in  Williamson style ( simple common cathode voltage amp directly connected to a concertina phase splitter). Coupling caps are Russian k40 PIO. Output transformers are recycled from an old Fisher receiver. Power supply is unregulated with cheap solid state rectification, but with an LCLC filter employing motor-run PIO caps. Generates about 4 watts.  Sounds way better than it should for a junk box project. Definitely a doable and interesting project.

I'd start with something like this http://www.nutshellhifi.com/Raven-MarkII.gif

It can be simplified without really hurting performance much, if at all -- in fact, some simplifications might, arguably, make it work better. For instance, if I were doing a first build, I think I'd build a simple linear regulator, use sand diodes, a CCS in the tail, and use a shunting style pot (config B here: http://www.raleighaudio.com/figure_17.htm )

The design is from this article, b/t/w/ http://www.nutshellhifi.com/triode1.html

-d

The amp I built is more a breadboard exercise to listen to the 4P1L than a finished design. At 4W output and 18dB gain, it's more a small speaker amp than a headphone amp. It's suitable for power hungry ortho's or perhaps a K1000, but it's way overkill for most headphones. I have no schematic but if you're still interested, PM me and I'll cook something up.

 

Doug pointed you in a really good direction. It's exactly what I'd do if I wanted to make something suitable for a traditional headphone like a Grado or Sennheiser.  Get yourself a couple of inexpensive Edcore input transformers that can be configured as phase splitters, run the secondaries into a pair of 5687 ( I often like to use small power tubes as drivers, so I might use something like a triode connected EL84 instead, assuming a fairly low impedance source) , connect the plates of the tubes to the primary of your output transformers, put a 10 watt 12 ohm resistor across the secondary for safety, add power supply and volume control to taste, and you're ready to roll.

 

I actually like this idea enough to pursue it further with something a little more sophisticated than a first pass breadboard prototype. Small p/p amps don't get enough attention around here. A good one actually has some advantages over the usual single ended designs that dominate the headphone world.

Edited by FrankCooter - 9/6/11 at 11:20am

One such headphone amp like this exists... in Indiana, iirc...   boy, sweet memories.