[IPodPJ]

I am wondering if a headphone amp exists that has no volume control (preamp) built-in. It would be just like a speaker amp that requires a separate preamp, but would power headphones. Without a potentiometer getting in the way of the signal, this might offer superior audio quality if driven by a good preamp.

I was just browsing Benchmark's website looking at the DAC1 PRE (not that I need one, I like the sound of my PS Audio DL3) and wondering if something like this exists. Anyone know?

 

[iriverdude]

Can you also active (split crossovers at line level) bi-amp or tri-amp headphones? You'd need phones with multiple drivers to do this.

 

[Dusty Chalk]

You mean, like a Musical Fidelity Supercharger? A power amp with unity gain? No.

 

[IPodPJ]

Why wouldn't it be possible? Are the volume steps and output wattage too sensitive for a headphone to be controlled by a separate pre-amp; the headphone drivers could easily be blown?

 

[Currawong]

I've seen at least one amp on here customised without a volume control. There's no reason why any regular amp couldn't easily be modded to just bypass the volume control.

 

[Dusty Chalk]

Yes, sorry, I stand corrected -- it could be done. I just know of no such thing commercially available.

 

[panda]

justin from headamp has made a few amps without volume control. the only one that i know of that came without one is one offered by krell which is damn near impossible to find since it was such a short production run...

 

[hypoicon]

Technically, PS Audio's headphone amp has no volume control-- their "gain cell" technology (as I understand it) does not attenuate the signal like a pot, but rather adjusts the gain of the amp section. Since there's no attenuation, there is no "volume control" but rather a gain control.

 

[sunseeker888]

Hypoicon is along the right lines here....a gain control is NOT a volume control, so technically it is a standalone power amp.

I agree, more manufacturers should try a non-integrated for headphones. You can bet your ass that there are lots of audio enthusiasts who would really like to use their high-end preamp in their headphone rig without having two volume pots in the signal path...

 

[Donald North]

Active preamps typically have more gain than is necessary for a headphone amp. Mine, for example, only has around 6dB on the IEC output setting and 1dB on the low setting.

If you turn the volume control on a headphone amp to max, then its volume control is essentially out of the signal path; there's no series impedance in the signal - only shunt.

Try feeding your cd player through an active preamp into a headphone amp with its volume control set at max. Then try feeding the cd player directly into the headphone amp using its built-in volume control. Which sounds better to you?

 

[Dusty Chalk]

Quote:

Originally Posted by sunseeker888 /img/forum/go_quote.gif Hypoicon is along the right lines here....a gain control is NOT a volume control, so technically it is a standalone power amp.

I think you're mixing up "being semantic" with "being right" -- when you move the knob, the volume goes up and down, right? Then it's still a volume control. You can design something similar without the gain control (with a fixed gain), right? Then it's still something that can be removed for a more minimal system.