Hi all,
I’m after recommendations on diy headphone amplifiers for a nice old pair of Sony headphones I’ve unearthed that seem to be very low impedance, at 14 ohms.
I have a nice case, in the size and style of a quad 405/34 stack it will sit on, some nice neutrik socketry, a 20va 18-0-18 transformer and the bits for a power supply.
I have read around the topic and have been convinced that class A is the way forward at these power levels.
The headphones themselves are rated at 1000mW, which at 14 ohms and 102dB/mW sensitivity would be deafeningly loud. Never the less I have calculated this to be about 10v pk-pk and 300mA output is needed ( to allow some margin).
I would be grateful for suggestions as to designs, so far I am liking the idea of knocking the three transistor amplifier on this forum together but would be interested in more powerful projects to build and try to compare.
I’m after recommendations on diy headphone amplifiers for a nice old pair of Sony headphones I’ve unearthed that seem to be very low impedance, at 14 ohms.
I have a nice case, in the size and style of a quad 405/34 stack it will sit on, some nice neutrik socketry, a 20va 18-0-18 transformer and the bits for a power supply.
I have read around the topic and have been convinced that class A is the way forward at these power levels.
The headphones themselves are rated at 1000mW, which at 14 ohms and 102dB/mW sensitivity would be deafeningly loud. Never the less I have calculated this to be about 10v pk-pk and 300mA output is needed ( to allow some margin).
I would be grateful for suggestions as to designs, so far I am liking the idea of knocking the three transistor amplifier on this forum together but would be interested in more powerful projects to build and try to compare.
Just use a small Class A power amp for 14 ohm load.
Very few of the headphone amps published here has 300mA bias.
And you probably want a low Zout of 1 ohm or so.
Or just build a Quad 405 clone.
Plenty of those around.
Cheers,
Patrick
Very few of the headphone amps published here has 300mA bias.
And you probably want a low Zout of 1 ohm or so.
Or just build a Quad 405 clone.
Plenty of those around.
Cheers,
Patrick
Thanks Patrick, perhaps one of that Nelson Pass design with no voltage gain and being very careful with the pre amp level?
Except that for 120dB transients, which is deafeningly loud, you only need 64mW... So plan for that, which is not that crazy power wise.
I think so too but have always sound that big amplifiers, in comparative terms of course, always sounded better to me than amplifiers with more modest power supplies and output sections.
This isn’t necessarily a function of power as much as current reserve, I may well me be talking nonsense but hey...
It’s an excuse to build stuff. 😀
This isn’t necessarily a function of power as much as current reserve, I may well me be talking nonsense but hey...
It’s an excuse to build stuff. 😀
Maybe have a look at this ? X-Altra HPA-1 Class A Headphone Amplifier or this "WHAMMY" Pass DIY headphone amp guide . Twice as much current as needed, in class A.
Or, if you really want power aplenty in a very simple circuit (no gain but none is needed with modern sources): LuFo Lite - a 1 Transistor SE Class A Headphone Amp
Or, if you really want power aplenty in a very simple circuit (no gain but none is needed with modern sources): LuFo Lite - a 1 Transistor SE Class A Headphone Amp