[Mr Rick]

  But don't you agree that adding resistance does have a smoothing effect on the sound? Obviously the effect is proportionate to the resistance, but at a certain point it should be audible or am I missing something? 

Adding resistance only allows an amplifier designed for speakers to drive headphones at the proper level. It produces no sonic changes whatsoever.

 

[thelonious58]

OP here again, at last! Firstly, many thanks to all of you for your erudite and informative replies (looks like I've stirred up a bit of a hornets' nest at times!)
So far I have tried the headphone output, which is far from awful, and also the CD player's own output with a high quality (Kimber) braided 2 x RCA to male 3.5, into which I've plugged my Topping NX1, into which I've plugged my MA900s, and I must say, the sound improved dramatically!
Best of all, I found that at low volume I was able to hear micro details from my CDs which I hadn't heard from the NX1 and HPs from my iPod (probably not surprisingly so!!)
Thanks again! 
BTW, please feel free to continue your discussion regarding the merits of the various methods - I find it very interesting

 

[Sonic Defender]

  Adding resistance only allows an amplifier designed for speakers to drive headphones at the proper level. It produces no sonic changes whatsoever.

I will not pretend to be so technically knowledgeable that I can refute this, but I am quite surprised as I have heard quite the opposite from a fairly wide experience base. I certainly am not in a position myself to say you are wrong, but I will have to dig around more and see where I have gathered information to the contrary.

 

[nicholars]

I don't think integrated sound BAD, they sound good if your integrated amp has a good headphone jack, especially with high impedance headphones like HD650, but (good) dedicated headphone amp does sound better, NAIM or similar are probably an exception because they are very expensive high end amps costs £1000's. I would like to try the naim dac with the built in headphone amp but far too much money.
 
Just tried out some headphones through D1050 headphone jack and through NAD 326Bee headphone Jack.... The 326Bee does sound decent.... But the D1050 sounds cleaner, more detailed, better controlled bass (although a bit less than the 326Bee) generally better.

 

[derbigpr]

  But don't you agree that adding resistance does have a smoothing effect on the sound? Obviously the effect is proportionate to the resistance, but at a certain point it should be audible or am I missing something? 

 
 
Haven't heard any such effects. Quite the opposite, the sound is very dynamic, quick and lively with high impedance headphones.

 

[guitargonaut]

I'm not arguing with anything that's been said in this thread - just pointing out the dangers of connecting most headphones directly to the speaker outs on most amps.  There is a risk and not knowing the level of experience or knowledge of another is why I felt it important to chime in.  I have seen headphones (and amps) destroyed by their loving owners because someone wasn't paying attention to what they were doing.
 
As far as my experience is concerned - I like what I like as do any of the other head-fi members out there.  We are here to share our experiences and by doing so helping others on their journey.  I didn't mean to insinuate any one particular route was better than any other.  Again - sound is subjective.  
 
I apologize if my comments offended anyone...

 

[Sonic Defender]

  I'm not arguing with anything that's been said in this thread - just pointing out the dangers of connecting most headphones directly to the speaker outs on most amps.  There is a risk and not knowing the level of experience or knowledge of another is why I felt it important to chime in.  I have seen headphones (and amps) destroyed by their loving owners because someone wasn't paying attention to what they were doing.
 
As far as my experience is concerned - I like what I like as do any of the other head-fi members out there.  We are here to share our experiences and by doing so helping others on their journey.  I didn't mean to insinuate any one particular route was better than any other.  Again - sound is subjective.  
 
I apologize if my comments offended anyone...

You sure didn't offend me, and I think your post was quite responsible and topical. Never hurts to have people make me think and less experienced users can benefit from the different viewpoints so I say no worries mate, good points.

 

[Mr Rick]

 
I will not pretend to be so technically knowledgeable that I can refute this, but I am quite surprised as I have heard quite the opposite from a fairly wide experience base. I certainly am not in a position myself to say you are wrong, but I will have to dig around more and see where I have gathered information to the contrary.

The gain control on your amp is a resistor. A variable resistor. When you turn the knob on your gain control do you change the sonic quality of the signal?  No, you only change the level of that signal. A fixed resistor does the same thing. Simples.

 

[Sonic Defender]

  The gain control on your amp is a resistor. A variable resistor. When you turn the knob on your gain control do you change the sonic quality of the signal?  No, you only change the level of that signal. A fixed resistor does the same thing. Simples.

Still not sure, but for now I have no way to say otherwise so in the absence of proof to the contrary, what can I say besides you sound knowledgeable and reasonable on the subject. I can say this much, we are not discussing just resistance, but a quantity of resistance. While try about the gain, that in itself doesn't mean that resistance elsewhere has no further impact.

 

[pp312]

When you consider the circuitous route the music takes from recording studio mixing desk to your ears I doubt a couple of resistors behind the HP socket is going to make any difference. In fact I often wonder why HP enthusiasts are so terrified of resistors, especially when even their dedicated amps are chock full of them. Maybe they should make a horror movie about resistors taking over people minds. (No, wait, seems like that's already happened).
 
Oh, and thanks, derbigpr, for stating so concisely what I'd been stumblingly trying to get across for a whole page before you fortuitously chimed in. I scanned your post with a magnifying glass but couldn't detect anything with which I disagreed, so in future I'll just wait till you post and then put, "What he said." It'll save a lot of time.
 

 

[Focker]

   
 
Anyway...I had these very same doubts until a about 2 years ago, when I actually went out to several hi-fi shops with my headphones (DT880 600 ohm at the time) and tested about 30 different integrated amplifiers and receivers ranging from entry level to high end. That was 2 years ago, and even though I have written notes somewhere, I won't go into detail about how each of the amps sounded. I'll just talk in general.  None of them, I repeat, NONE of them, had bad headphone outputs. 

 
Wow, that's completely different than my experience. When I first got into headphones in late 2011, one of my first buys was the DT880s. I tried them out on an Onkyo 50 watt receiver I have and they sounded thin and lifeless. I called Onkyo to discuss it with them and they said the jack on the receiver was only rated to 300ohms. Onkyo must have really upgraded their headphone sections, cause I can't imagine anyone using it to drive the DT880s. 
 
The only other example I can speak to is the Peachtree Audio Nova 125...an absolutely fantastic integrated. Their headphone jack is rated to 600 ohms and does sound pretty good with some of my headphones, but nothing like my dedicated headamp(s). 

 

[pp312]

Obviously you should have bought the 250 ohm DT880.

 
Actually I'm telling lies when I say I couldn 't pick a fault with derbigpr's remarks. I've certainly found a greater variation of performance than he seems to suggest, but he's right in saying that the sound of the amplifier with speakers is the sound you're going to get with headphones--at least 90% of the time. Obviously that means you need to choose a good sounding amp if you want good sound. There is nothing inherently inferior about an integrated or receiver; it comes down to the design and, as with all components, synergy. IOW, if you've got bright, thin-sounding headphones you don't want an amp that exaggerates those characteristics.
 
So, to recap, there is no mystery surrounding integrateds and receivers in terms of driving headphones. It all comes down to electrical circuits boosting signals, and how well they do that will determine the sound you get. The problem with Head Fi at the moment, and in fact throughout its history (I've been here since 2001), is the myth of the 5c op amp. We've been through it all before so many times. It gets challenged every so often, thoroughly disproved, yet rises again each time, seemingly stronger. Dare I suggest there are powerful commercial forces at work? Nah, I daren't.

 

[Focker]

  Obviously you should have bought the 250 ohm DT880.

 
 

 
lol, yep

 

[nicholars]

  Obviously you should have bought the 250 ohm DT880.

 
Actually I'm telling lies when I say I couldn 't pick a fault with derbigpr's remarks. I've certainly found a greater variation of performance than he seems to suggest, but he's right in saying that the sound of the amplifier with speakers is the sound you're going to get with headphones--at least 90% of the time. Obviously that means you need to choose a good sounding amp if you want good sound. There is nothing inherently inferior about an integrated or receiver; it comes down to the design and, as with all components, synergy. IOW, if you've got bright, thin-sounding headphones you don't want an amp that exaggerates those characteristics.
 
So, to recap, there is no mystery surrounding integrateds and receivers in terms of driving headphones. It all comes down to electrical circuits boosting signals, and how well they do that will determine the sound you get. The problem with Head Fi at the moment, and in fact throughout its history (I've been here since 2001), is the myth of the 5c op amp. We've been through it all before so many times. It gets challenged every so often, thoroughly disproved, yet rises again each time, seemingly stronger. Dare I suggest there are powerful commercial forces at work? Nah, I daren't.

 
All I can say is I have tested integrated amps and headphone amps and a GOOD headphone amp sounds better than an integrated (except possibly NAIM etc.) a BAD headphone amp can sound worse than an integrated amp with high impedance headphones... But a good headphone amp will sound better with headphones especially low impedance which most headphones are these days. So are integrated amps usable for headphones : obviously yes, especially if you have high impedance headphones as most integrated have high impedance... Is a good headphone amp better than an integrated (except possibly NAIM etc) ... Yes, if you want to save money then an integrated is fine... if you want the best possible sound with multiple pairs of headphones a headphone amp is best.

 

[derbigpr]

   
Wow, that's completely different than my experience. When I first got into headphones in late 2011, one of my first buys was the DT880s. I tried them out on an Onkyo 50 watt receiver I have and they sounded thin and lifeless. I called Onkyo to discuss it with them and they said the jack on the receiver was only rated to 300ohms. Onkyo must have really upgraded their headphone sections, cause I can't imagine anyone using it to drive the DT880s. 
 
The only other example I can speak to is the Peachtree Audio Nova 125...an absolutely fantastic integrated. Their headphone jack is rated to 600 ohms and does sound pretty good with some of my headphones, but nothing like my dedicated headamp(s). 

 
 
The only receivers I've heard were Marantz and Denon, all that I've heard from Onkyo were integrated amps.  As I said, in general integrated amps sounded better than receivers, obviously, but none of them sounded bad.