Headphones driven from speaker outputs.

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antonio66

Headphones driven from speaker outputs.

Unread post by antonio66 » Mon Sep 11, 2017 8:03 am

I received an email from Artisan Silver Cables which I have copied below:-

...or to put it another way: driving the hell out of your headphones (carefully!)...
 
So here's the story: we were recently contacted by a customer, who wanted us to make a pure silver adapter cable to connect the speaker outputs of his power amplifier to his headphones(!)   
 
We were a little concerned about the potential to over-drive the headphones (or the customer's ears!), but we went ahead and made the cable, whilst advising him that he would need to be very circumspect with the volume control...  
 
The cable was around 75cm in length and fitted with WBT's superb 0610-AG banana plugs (the same plugs we like to use on our speaker cables), going to a Neutrik 1/4 inch stereo jack socket.

Once the cable was made, it was tested in one of my personal systems, with a Red Rose amp, rated at around 30 watts per channel, driving my Sennheiser HD-650 headphones.  
I was unprepared for the result.  
The set-up absolutely trounced my usual headphone amp, which I had considered to be of decent quality - the music became extremely vibrant, pure, open & powerful, with far better resolution of very low-level information - just fantastic. In fact, the performance was far better than I had imagined was possible with HD-650s.  
 
The way the amplifier uncompromisingly gripped and dominated the headphones - leading to fantastic sound - reminded me of reading Hi-fi News magazine back in 1985 (when I was first becoming interested in high-end hi-fi), with Ken Kessler's inspiring description of the way the fantastically muscular new Krell power amps exhibited "vice-like grip" over the speakers, forcing the speakers to sound better than you'd think possible... 
 
Clearly, our customer's idea was excellent! 

Caveats?  
Yes, a few:  
1. Clearly, great care is needed with setting low volumes - also the whole system will need to be of excellent quality and with very low noise.  
2. The high sensitivity of the headphones may reveal previously unheard hiss and/or hum. For this reason, valve-based equipment may prove to be a problem, with it's lower signal-to-noise ratios.  
3. Higher sensitivity headphones, designed to work with portable equipment will obviously be unsuitable. This is only going to work well with headphones that like to be driven and are expected to be used with dedicated headphone amps.  
 
So, with the above provisos, this may be a great way of driving high-end headphones - and to my ears, superior to the great majority of specialist headphone amps.  
Our customer simply had this to say:

"Hi Alister, 
thank you very much for the adapter cable.  
I got it last week and it has been running continuously since then. 
It already sounded great right out of the box.  
I can honestly say, that my headphone setup never sounded this good...
...Kind Regards, Jens"

The 1/4" stereo jack socket confused me so this is what he meant. http://www.neutrik.com/en/audio/plugs-a ... nj3fc6-bag

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Dr Bunsen Honeydew
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Re: Headphones driven from speaker outputs.

Unread post by Dr Bunsen Honeydew » Mon Sep 11, 2017 9:56 am

That is what NVA headphone amps are but with a series resistor to drop volume and protect the headphones.

joe
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Re: Headphones driven from speaker outputs.

Unread post by joe » Mon Sep 11, 2017 10:10 am

Many years ago I had a device called 'The Can Opener' which was driven from the speaker outputs; I suspect it worked in the same way as the NVA headphone amp. I didn't keep it because it was a PITA disconnecting it and re-connecting the speakers, and vice-versa. It was made in Bradford IIRC.

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Re: Headphones driven from speaker outputs.

Unread post by Ithilstone » Mon Sep 11, 2017 12:21 pm

I use to do that with my HE-6s now I use NVA amps to drive them so I dont have to as HP socket is directly connected to speakers taps (with small high quality resistor to drop volume)
PC+Foobar2000;
DACs: Arcam Delta Black Box; Grace m9XX; NuForce Icon HDP;
AMPs: NVA AP10H + DoubleBBPSU [one case prototype :mrgreen: ], NVA AP70 SA, NVA AP20,
Speakers: Cubettes, Royd Envoy (Half Doc Modded);
Headphones: Hifiman HE-6, Hifiman HE-400i, Beyerdynamic DT 990 Pro (250ohm), Superlux HD681 EVO,
NVA BMU

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Re: Headphones driven from speaker outputs.

Unread post by Fretless » Tue Jan 23, 2018 11:05 am

Just discovered something interesting which reminded me of this thread. A while ago I started using my aged Sansui AU-217 (1978) as a headphone amp and was extremely impressed with the SQ. With only one input needed I plugged a DAC into the TAPE OUT sockets which bypasses the selector switch and effectively provides a direct input to the pre-amp.

Image

Reading some online comments about these amps I discovered that this Sansui AU series have no dedicated headphone section but use the main speaker outputs routed via resistors to power cans. Which could explain why the performance is so good.

This really is a superb-sounding amp as are all in Sansui's AU-x17 series and truly excellent as a headphone amplifier. :dance: :guiness;

:music-listening: :music-listening: :music-listening:
NVA: P50sa - SSP - A40 - LS6 - Cube3
Digits: RPi 2B / Allo DigiOne / Volumio / Tomanek ULPS / AQ Jitterbug
CD Transport: Cambridge CXC DAC: Metrum Acoustics Musette
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Re: Headphones driven from speaker outputs.

Unread post by Ithilstone » Tue Jan 23, 2018 11:22 am

Fretless wrote:
Tue Jan 23, 2018 11:05 am
I discovered that this Sansui AU series have no dedicated headphone section but use the main speaker outputs routed via resistors to power cans. Which could explain why the performance is so good.
Well exactly the same thing can be said about all NVA amps with HP socket...

:mrgreen: :mrgreen: :mrgreen:

p/s it was standard practise up till late 70s I believe so almost all amps ( or at lease Japanese ones)up to 80s didn't have dedicated HP amp build in
PC+Foobar2000;
DACs: Arcam Delta Black Box; Grace m9XX; NuForce Icon HDP;
AMPs: NVA AP10H + DoubleBBPSU [one case prototype :mrgreen: ], NVA AP70 SA, NVA AP20,
Speakers: Cubettes, Royd Envoy (Half Doc Modded);
Headphones: Hifiman HE-6, Hifiman HE-400i, Beyerdynamic DT 990 Pro (250ohm), Superlux HD681 EVO,
NVA BMU

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Fretless
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Re: Headphones driven from speaker outputs.

Unread post by Fretless » Tue Jan 23, 2018 11:52 am

Good to know - thanks.
NVA: P50sa - SSP - A40 - LS6 - Cube3
Digits: RPi 2B / Allo DigiOne / Volumio / Tomanek ULPS / AQ Jitterbug
CD Transport: Cambridge CXC DAC: Metrum Acoustics Musette
Cans: AudioQuest NightHawk Digital i/c: Oxypure OCC coax & optical

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Re: Headphones driven from speaker outputs.

Unread post by CN211276 » Tue Jan 23, 2018 11:58 am

I can recall that Sansui amp being very well thought of before the NAD came on to the scene.
I set a course just east of Lyra
And northwest of Pegasus
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Sonore microRendu/McRU PS, AQ J-bug, Wirewold Ultraviolet, Chord Qutest, NVA P50SA, NVA A80sMk2, NVA Cube 3s, NVA LS6, NVA TIS mk2, NVA SSP mk2, Rega Planar 3, Denon DL-110, NVA Phono 1, NVA BMU, Grado SR 325e, headphones, Chord Mojo.

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Re: Headphones driven from speaker outputs.

Unread post by Vinyl-ant » Tue Jan 23, 2018 12:09 pm

Iirc there are a couple of circuits out there for diy purposes so that cans can be driven by any amp in this way
I built one a few years ago for a set of sennys, havent got the cans any more but I might still have the box I built somewhere. Sounded better than the musical fidelity x cans I was using for them.
I have a set of audio technica ath7 electret cans now and they are driven off the speaker outlets off my pass f5 via a box, not sure if its got a resistor network or a set of transformers in it as I havent opened it up to look.
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Re: Headphones driven from speaker outputs.

Unread post by Fretless » Tue Jan 23, 2018 1:39 pm

I had a set of ATH-7 once, wore them out completely. Brilliant cans!
NVA: P50sa - SSP - A40 - LS6 - Cube3
Digits: RPi 2B / Allo DigiOne / Volumio / Tomanek ULPS / AQ Jitterbug
CD Transport: Cambridge CXC DAC: Metrum Acoustics Musette
Cans: AudioQuest NightHawk Digital i/c: Oxypure OCC coax & optical

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