[Carl]

Okay, here's what I'm looking for:

A pre-amplifier (or prehaps a receiver) with Dolby Headphone, that outputs a DH processed signal over the line-level outputs, not just the headphone jack.
From there I'll feed it into a nice headphone amp.

All preamps and receivers I've tried have had terrible headphone stages. Yuck.


Before any suggests just using stereo, let me say that multichannel material sounds significantly better using simulated surround to my ears than a stereo downmix does. The setup I have planned will allow me to switch between stereo and DH at my leasure anyway, so I can have it both ways.


Thanks everyone.

 

[DJ_JonnyV]

Hey, Carl, I'm using some Senn HD595s with Dolby Headphone in one of my home setups. I am using the headphone out jack on my Marantz SR5500 receiver into a Shellbrook Audio Lab Maxi Moy amp. I am fairly positive that the Dolby Headphone signal cannot be outputted via analog outs from a preamp/receiver/or anything else for that matter. I think you are stuck with having to use the headphone jack. I will say that I get very good results with my Marantz receiver and using a custom cable from shellbrook also. I have no audible audio hiss until turning the amp volume way up, and the headphone jack passes the Dolby signal quite well. Not to mention the fact that Marantz receivers make pretty darn good A/V receivers and are known for not cutting corners and sound very musical. It's kind of like a win-win. Also, I have spoken with Marantz tech support, and they informed me that the headphone section on the 5500 is identical to the 7500 and 8500. Hope this helps.

 

[rickcr42]

Optionally maybe you can have a technician bypass the the headphone amp stage making the headphone output a line output.It would void any warranty (unless reversable as in jumper wires clipped in) but a possible work around if this is something important to you.

rickster

 

[rickcr42]

BTW-I want to add that since Dolby Headphone is coded directly into the DSP chip abd that chip makes routing decisions there most likely is no option to getting the multichannel Dolby signal to the line outputs short of major internal wiring and adding a normal/headphones switch to the stereo line outputs.You may have a "sythesized surround" output option to the line outs but that uses entirely different processing choices geared to loudspeaker listening so would not translate well to headphone use usually though maybe worth checking out just for the h*ll of it.

 

[Carl]

Quote:

Originally Posted by rickcr42 Optionally maybe you can have a technician bypass the the headphone amp stage making the headphone output a line output.It would void any warranty (unless reversable as in jumper wires clipped in) but a possible work around if this is something important to you. rickster

This sounds like fun. Got any more info on how I would go about doing this?
I quite enjoy modding my gear, as my DVD player will attest.


Failing that, I agree with DJ_JonnyV about Marantz having pretty good headphone stages.

 

[rickcr42]

Quote:

This sounds like fun. Got any more info on how I would go about doing this? I quite enjoy modding my gear, as my DVD player will attest.

Pretty much player-to-player variable but the quick and dirty of it is.

1-remove the resistor at the output of the headphone stage that connects to the jack.They all have them for load isolation.Just snip the resistor lead on the board at the AMP end (there is a reason for this in step #2)

2-From the input of the headphone amp add a wire to the headphone output jack.to do this simply attach a wire to the the output side of any coupling capacitor or input resistor to the stage.The other end of this wire will attach to the JACK side of the amp output resistor.The reason for doing it this way is accessability to the pc board pads may be limited nut unless the parts are all SMD you have a tie point on top of the board to "jump over" the present output stage.It is also notable that headphone jacks on consumer equipment are all board mounted so getting access to the individual pins usually a losing battle so you need a place to securely attach the new wire and pcb soldered passive poarts the ideal solution.Consider them like "tie points" in a point-to-point wired amplifier.

You best bet is to attempt to find the service manual online for your particular player and identify the parts/cicuit structure so you can determine the point of tapping into the line level signal.You may find you can simply replace the output section with a pin-for-pin compatible part better suited to line driving duties and that would be the ideal.


Going to an extreme would be to add a separate "Line level module" on a perf board internally with its own audio and voltage regulator sections then (warranty voided !) drilling a hole in the side of the chassis for the addition of a dedicated output connector.You still would need the schematic to find the ideal point to tap into the signal but would allow the freedom to upgrade this section at will.


BTW-Be extremely careful when poking around inside the unit.Replacing a DSP chip is not easy and not cheap and these are easily wiped out from ESD or putting a load on it that can not be handled by the output section driver.Most likely it will have a line section opamp preceeding the headphone section amp and that is where you want to tap in unless it is such a crappy device that you want to also bypass this stage but beware man !
You need to know if the DSP/CODEC/DAC is capable of driving the replacement chip without self destructing ! You may need to buffer this point to be safe and to isolate the chip from harm.

hope this helps a bit

rickster

 

[Carl]

Quote:

Originally Posted by rickcr42 Pretty much player-to-player variable but the quick and dirty of it is. 1-remove the resistor at the output of the headphone stage that connects to the jack.They all have them for load isolation.Just snip the resistor lead on the board at the AMP end (there is a reason for this in step #2) 2-From the input of the headphone amp add a wire to the headphone output jack.to do this simply attach a wire to the the output side of any coupling capacitor or input resistor to the stage.The other end of this wire will attach to the JACK side of the amp output resistor.The reason for doing it this way is accessability to the pc board pads may be limited nut unless the parts are all SMD you have a tie point on top of the board to "jump over" the present output stage.It is also notable that headphone jacks on consumer equipment are all board mounted so getting access to the individual pins usually a losing battle so you need a place to securely attach the new wire and pcb soldered passive poarts the ideal solution.Consider them like "tie points" in a point-to-point wired amplifier. You best bet is to attempt to find the service manual online for your particular player and identify the parts/cicuit structure so you can determine the point of tapping into the line level signal.You may find you can simply replace the output section with a pin-for-pin compatible part better suited to line driving duties and that would be the ideal. Going to an extreme would be to add a separate "Line level module" on a perf board internally with its own audio and voltage regulator sections then (warranty voided !) drilling a hole in the side of the chassis for the addition of a dedicated output connector.You still would need the schematic to find the ideal point to tap into the signal but would allow the freedom to upgrade this section at will. BTW-Be extremely careful when poking around inside the unit.Replacing a DSP chip is not easy and not cheap and these are easily wiped out from ESD or putting a load on it that can not be handled by the output section driver.Most likely it will have a line section opamp preceeding the headphone section amp and that is where you want to tap in unless it is such a crappy device that you want to also bypass this stage but beware man ! You need to know if the DSP/CODEC/DAC is capable of driving the replacement chip without self destructing ! You may need to buffer this point to be safe and to isolate the chip from harm. hope this helps a bit rickster

Thank you immensely. This sounds like exactly what I'd like to do. All going well I coukd craft a perfectly matched headphone system for my needs.

I think I'll take some time to research and plan how I'm going to do this, but I'm seriously going to try it. If any one has any more ideas or suggestions, I'd love to hear them.

I guess the big problem now is deciding which pre-pro to use as my base. There's so much choice...