redchiro
New Head-Fier
- Joined
- Jan 14, 2006
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I posted an inquiry on a Sony website about the technical aspects of the headphone circuit in my Sony STR DA-7ES multichannel receiver.
(I use this for a modest home theater and it actually sounds pretty good playing CD's, SACD's, DVD-A through it).
It has one of those headphone circuits where you plug in the 'phones and the speakers automatically mute. The answer I got was, that this receiver, has no separate headphone amp/circuit built in. It simply uses a voltage divider with a 680 ohm resistor across the L/R speaker outputs.
In theory this sounds good-like I would be getting the same pure signal that is fed to the speakers. Instead, it is just shunted to the headphone jack. There are no cheap op-amps in the signal path. I notice that there is certainly tons of power (volume).
In contrast, the headphone output in my Sony XA-777ES CD/SACD player doesn't get much louder as you turn the pot past 12-o-clock (driving HD-650's). It is loud enough for me, but barely gets there-no guts at all. It apparently uses an "afterthought" op-amp based circuit.
My Perreaux SXH1 has plenty of power but even it can't play as loud as the receiver headphone out. Not that I would ever need anything near that kind of volume.
So in terms of quality, is there anything inherently wrong with this inexpensive, resistor across the speaker outputs approach to a headphone amp? Is it about impedance matching, damping, and things like that that make a dedicated headphone amp better at it's sole function?
The rcvr's headphone circuit sounds good to my ears. I have not done an extensive comparison btw. it and the Perreaux but there is no obvious difference in tonal shift upon a quick comparison. No added harshness, or loss of detail, etc.
Thanks for any quick "electronics 101" lessons.
(I use this for a modest home theater and it actually sounds pretty good playing CD's, SACD's, DVD-A through it).
It has one of those headphone circuits where you plug in the 'phones and the speakers automatically mute. The answer I got was, that this receiver, has no separate headphone amp/circuit built in. It simply uses a voltage divider with a 680 ohm resistor across the L/R speaker outputs.
In theory this sounds good-like I would be getting the same pure signal that is fed to the speakers. Instead, it is just shunted to the headphone jack. There are no cheap op-amps in the signal path. I notice that there is certainly tons of power (volume).
In contrast, the headphone output in my Sony XA-777ES CD/SACD player doesn't get much louder as you turn the pot past 12-o-clock (driving HD-650's). It is loud enough for me, but barely gets there-no guts at all. It apparently uses an "afterthought" op-amp based circuit.
My Perreaux SXH1 has plenty of power but even it can't play as loud as the receiver headphone out. Not that I would ever need anything near that kind of volume.
So in terms of quality, is there anything inherently wrong with this inexpensive, resistor across the speaker outputs approach to a headphone amp? Is it about impedance matching, damping, and things like that that make a dedicated headphone amp better at it's sole function?
The rcvr's headphone circuit sounds good to my ears. I have not done an extensive comparison btw. it and the Perreaux but there is no obvious difference in tonal shift upon a quick comparison. No added harshness, or loss of detail, etc.
Thanks for any quick "electronics 101" lessons.