Using Headphone out as Preout ?

[Hari Iyer]

Hari,

that’s a really funny story. So you took a unknown headphone of unknown response and unknown impedance from a medical device possibly not optimised to listen to audio at all and compared it to fairly low end deck from Sony. (TC fx44 Was assembled in india with a matching amp) and used that to extrapolate that the Sonytape deck headphone amp is the best in the world. this kind of extrapolation is really troubling. The story gets even more incredulous that the guys who own a 2 crore machine, allowed you to take a purpose matched headphone from a Mission cricital medical device to your home and try with your amps.


On a lighter note, I hope you informed Sony, I am sure they can stop spending crazy R&D money developing new TOTL amp systems as they already have the best ever hidden in a midfi deck from 3 decades ago. And please tell all the guys in head-fi too. Considering the amount they spend on headphone amps, I am sure they will be thrilled to scoop up any living Sony decks at basement prices to finally end their upgraditis.

thanks for sharing. I love your stories. Very entertaining.

edit: is this it?
View attachment 45074

Alright. I shall WA you.

Siemens acquired Acuson somewhere in 1998 if I am not mistaken. From there on the products became not so good quality.

 

[spirovious]

Color Doppler Headphone may not respond flat/perfect to full 20-20khz range. So may not give the best audio performance.

 

[spirovious]

I don't agree.
Typically, the headphone out is tapped from the speaker out, where the voltage is rail To rail (less a little bit). The line out is 2V or 4V (prof equipment). The amp input is high impedance, so doesn't need a high current source.

The amp which l was talking is PM7005 which doesn't have preout but a dedicated headphone out.Idea was to add a subwoofer.

 

[surfatwork]

The headphone out in the PM 7003 is tapped from the speaker out (you can check the service manual). I would assume it is the same in the 7005 also.
You should be fine, like I said, just keep the headphone volume low.
Or if your sub amp has speaker level inputs, use that. Result will pretty much be the same.

 

[spirovious]

The headphone out in the PM 7003 is tapped from the speaker out (you can check the service manual). I would assume it is the same in the 7005 also.
You should be fine, like I said, just keep the headphone volume low.
Or if your sub amp has speaker level inputs, use that. Result will pretty much be the same.

PM7005 has a separate Headphone amp and one can use speaker out with headphones plugged in or disable speaker out with one button.

specs of PM7005 says
" Fully Discrete Headphone Amplifier
For superb sound quality with the widest range of headphone types, the PM7005 features a fully discrete headphone amplifier that is able to handle just about any headphone type, regardless of impedance or sensitivity. The high quality gold plated ¼” headphone jack is compatible with audiophile and studio headphones and adapters."

It doesn't have Sw out , front preout or speaker B.

 

[surfatwork]

Sure. What I said still Holds.
Connecting something of higher impedance to a source doesn't usually cause issues. Because it doesn't draw more current.
.

 

[abeyaby]

I use the headphone out on my Arcam AVR 300 to power up a tubeamp and it works like a charm. Thought of this hack about a year back and it works fantastic for me.

 

[spirovious]

Tried it yesterday with Poweramp. Volume control is an issue.Can't go beyond 8 O'clock as it gets very loud. I tested with caution though.Sound of marantz pre was much better than compared to dcb1, B1 and SSP.

 

[josedandrew]

Tried it yesterday with Poweramp. Volume control is an issue.Can't go beyond 8 O'clock as it gets very loud. I tested with caution though.Sound of marantz pre was much better than compared to dcb1, B1 and SSP.

Hi,
Did you finally connect the sub to headphone out. I am planning to add a sub to my pm6006 stereo setup.
Any guidance will be much appreciated.

 

[spirovious]

Hi,
Did you finally connect the sub to headphone out. I am planning to add a sub to my pm6006 stereo setup.
Any guidance will be much appreciated.

I didn't yet, but output of headphone out seems much higher. With Poweramp, I had to set it correctly so that speakers won't get damaged. Subwoofer has volume control ,so can be turned down very low. Still you need to check how much SW can accept input voltage to prevent damage. Headphone out is actually little amplified out and not preout.

 

[Yogesh]

When designed according to convention, a line input expects a line level signal, which is to say that it expects a maximum signal amplitude of about 1Vpp (peak to peak voltage) for consumer audio, and about 3.5Vpp for pro audio. A line level output also has an impedance of less than 1k (1000) ohms, and the output swings symmetrically above and below the signal ground point; a line level input has an impedance of at least 10k (10 000) ohms, and typically uses capacitive coupling to remove any DC offset that may be present.

Most “headphone out” jacks will provide a signal that meets the amplitude limits, so there should be little difficulties doing what you're proposing.

Source - Quora

 

[Yogesh]

When designed according to convention, a line input expects a line level signal, which is to say that it expects a maximum signal amplitude of about 1Vpp (peak to peak voltage) for consumer audio, and about 3.5Vpp for pro audio. A line level output also has an impedance of less than 1k (1000) ohms, and the output swings symmetrically above and below the signal ground point; a line level input has an impedance of at least 10k (10 000) ohms, and typically uses capacitive coupling to remove any DC offset that may be present.

Most “headphone out” jacks will provide a signal that meets the amplitude limits, so there should be little difficulties doing what you're proposing.

Source - Quora