Can we expect 300B/2A3 Bottlehead headphone amp someday?

[Paul Birkeland]

The BeePre does not use an output transformer.  By comparison the 300B in a power amp will feed an 18:1-25:1 output transformer that will step the noise way, way down.

The BeePre 1 would probably struggle a bit with your second scenario, but BeePre 2 will work with such a system. 

[Beefy]

I'm going to throw my weight behind a general call for a DHT headphone amp from Bottlehead.

Backstory and rationale..... I've owned and enjoyed my Crack for over 10 years. But I have an itch for a new amp build that no current product on the market can scratch. Crackatwoa might be 'better' but I want something different. I want a more involving and crazy build than SEX offers. Mainline is by all accounts an absolutely stellar headphone amp, but the build, looks and sensibleness of it just doesn't make my fun parts tingle - I want to build something stupid and over the top, with genuine tube-flavor-tube-rolling-and-tweaking credentials. Stereomour is oh-so-close in that it seems like it can be hooked up for headphone use, but the high gain seems like it would really only be suitable for high impedance low sensitivity phones. These days I very much like the sound of low impedance high sensitivity Focals and planars, which would be a definite no-go.

In terms of competitors, the Elekit 8900 is very intriguing. But the high gain, transformer tube load and the resistor-dividers-on-a-speaker-amp-to-tame-noise-and-gain headphone output really dampens my enthusiasm. The one commercial product that really lights my fire is the Donald North Stratus, but it's no fun if I can't build one of those myself!

In a nutshell, I would be first in line for a DIY DHT amp designed specifically for headphones, and I think a lot of others would be *very* interested as well. Something with sensible gain, and a very low output impedance and noise that is capable of driving low impedance high sensitivity phones. Is this a fantasy? An impossible unicorn? Maybe. But if anyone can make it happen, it's Bottlehead.

[Paul Birkeland]

For those super sensitive headphones, the Mainline is going to make a lot of sense.  The 6C45PI is a much quieter operator than the 2A3 in more ways than one.  You have certainly qualified some of the challenges with your request, as driving the noise levels down requires throwing away useful power with resistor dividers or an unusual output transformer with a 1 or 2 ohm output configuration (you wouldn't want to use an OT with a 16 ohm winding tapped at 1 or 2). 

Do you think if the SEX amp had more interior space for modification that it might be a better fit?

[Beefy]

For those super sensitive headphones, the Mainline is going to make a lot of sense.  The 6C45PI is a much quieter operator than the 2A3 in more ways than one.  You have certainly qualified some of the challenges with your request, as driving the noise levels down requires throwing away useful power with resistor dividers or an unusual output transformer with a 1 or 2 ohm output configuration (you wouldn't want to use an OT with a 16 ohm winding tapped at 1 or 2). 

Do you think if the SEX amp had more interior space for modification that it might be a better fit?

Oh, I'm absolutely sure that Mainline and SEX would both be sensible choices. I'd probably enjoy building them, and maybe I would be more interested if there was some expanded options for tweaking and playing.

But I just really, really, really, really want to build a big DHT amp, and I don't do speakers. It's irrational, it's silly, it's selfish, it makes no sense..... but that's audiophilia, right?

[Paul Birkeland]

There should be nothing stopping you from buying a Kaiju and adding a headphone jack to the front, especially if you are performing volume control elsewhere.