Unplugging the headphones or not?
Printed From: Graham Slee Hifi System Components
Category: Headphone Audio
Forum Name: Graham Slee Headphone Amps
Forum Description: Questions, answers and product information zone for Graham Slee Headphone Amplifiers
URL: https://www.hifisystemcomponents.com/forum/forum_posts.asp?TID=1200
Printed Date: 27 Mar 2026 at 4:02am Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: Unplugging the headphones or not?
Posted By: suede
Subject: Unplugging the headphones or not?
Date Posted: 26 Sep 2011 at 4:59pm
Hi everybody I have a little query... When you all are done with a listening session do you keep the headphones plugged into the amp or do you unplug them leaving the amp without a load? I have the UL and (coupled with Grados at least) the background hiss is quite noticeable when silent or without input signal. What are you're thoughts about this, could it in length be harmful for the headphones to never have the transducers rest, or could it even be benefitial? Lately I've been unplugging my cans and then it actually seems that they're a bit smoother when I'm using them the next time, but it's hard to tell since the comparing sessions are so many hours apart.
Also, on another subject completely, how much does speaker cables vary in quality? I have a pair of semi thick jenving cables that cost about £1 a foot. Could there be much real improvement there or are the more expensive cables just for show? 
Grateful for any input or views on this!
Johan
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Replies:
Posted By: jamescodway
Date Posted: 26 Sep 2011 at 8:45pm
Hi there 
To avoid repetition... the thread below includes some broad references to your question.
http://www.gspaudio-community.activeboards.net/help-with-headphones_topic1171_page1.html" rel="nofollow - http://www.gspaudio-community.activeboards.net/help-with-headphones_topic1171_page1.html
Best
James
------------- Voyager - HD25
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Posted By: Graham Slee
Date Posted: 27 Sep 2011 at 12:37am
I'll just add that with other headphone amps it is probably a good idea to unplug them.
This is because with many, the output coupling is direct - a DC level (DC coupling).
A DC coupled output should be 0V but can vary slightly with input offset - this in itself won't damage your headphones.
However, some DC coupled amps have been known to go unstable and flip to one voltage rail or another. When this happens, the DC voltage will "fry" the transducers, thus destroying your very expensive headphones.
I would never design a DC coupled amp in this age on that precept alone! Headphones are too expensive for a company to survive with damages claims.
So, with our headphone amps, I AC couple them, which means an output capacitor, and everybody goes ape when they hear that, because they have been fed misinformation (this IS the misinformation age after all).
True, an output capacitor on a dual supply amp design will distort crazily at its turnover frequency, but the thing they don't understand is all that distortion disappears once the capacitor has a bias voltage (didn't John Linsley Hood make that clear enough?), and all our unipolar supply amp designs (Solo, Voyager, Novo) provide that bias voltage by default.
Therefore, because there is no likelihood of any DC with our amps, your headphones are safe left connected.
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
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Posted By: franklin
Date Posted: 27 Sep 2011 at 3:41am
Graham Slee wrote:
So, with our headphone amps, I AC couple them, which means an output capacitor, and everybody goes ape when they hear that, because they have been fed misinformation (this IS the misinformation age after all).
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Irony all those ape have a capacitor on their tweeter. I don't know they don't know that or ...
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Posted By: Graham Slee
Date Posted: 27 Sep 2011 at 11:04am
Yes, and the tweeter is the most important for the stereo "projection" etc.
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
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Posted By: suede
Date Posted: 27 Sep 2011 at 2:45pm
Posted By: Fatmangolf
Date Posted: 27 Sep 2011 at 11:21pm
franklin wrote:
Irony all those ape have a capacitor on their tweeter. I don't know they don't know that or ...
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A very good point!
------------- Jon
Open mind and ears whilst owning GSP Genera, Accession M, Accession MC, Elevator EXP, Solo ULDE, Proprius amps, Cusat50 cables, Lautus digital cable, Spatia cables and links, and a Majestic DAC.
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Posted By: suede
Date Posted: 28 Sep 2011 at 3:48pm
Graham Slee wrote:
However, some DC coupled amps have been known to go unstable and flip to one voltage rail or another. When this happens, the DC voltage will "fry" the transducers, thus destroying your very expensive headphones.
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Just a thought, could this happen to loudspeakers as well if you leave your regular amp on?
Johan
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Posted By: Graham Slee
Date Posted: 28 Sep 2011 at 4:42pm
Unfortunately it has been known to happen. I cannot say which amps do it regularly...
The Proprius will be capacitor coupled thus avoiding this situation.
------------- That none should be able to park up and enjoy the view without a smartphone and the knowledge in how to use apps
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