[MaZa]

Quote:

Originally Posted by beamthegreat /img/forum/go_quote.gif so if the output is in rca and I converted it to 1/8 and plug my headphones in it, will it work??

Errr, what? I thought we are talking about the headphone output, usually 1/4 socket, that most normal stereo amplifiers have in the frontpanel.

 

[krmathis]

^ While I thought we were talking about speaker level output, as is to be expected on a stereo (speaker) amplifier.
Hmmm...

 

[Bengt77]

I used to always drive my heaphones directly from the headphone jack on my Harman Kardon AVR. Now that I have a CORDA 3MOVE, though, I've found that going from my MacBook via USB to the 3MOVE and from there to either of my headphones sounds a lot better. Not all headphone outputs on home amplifiers and receivers are indeed created equal, it seems.

 

[ProtegeManiac]

I use my NAD304; I haven't opened it up completely but last time I cleaned the insides I noted the headphone driver had a small PCB on it with some sort of shilding wrapped around it. I think it had an IC and definitely some caps, most likely a CMOY-type.

How does it sound? Drove my AKG K66 well enough before but is fantastic with the SR225. Its sensitivity definitely helps too, but through this I realized how transparent the NAD's preamp is. Using the output from my Marantz CD60 and using that as transport through a passive-output DAC-AH, it was night and day. By now I'm using the DAC and amp with the PC (haven't used the full rig in months because of work), too bulky but it'll hold me over till I get a proper desktop amp.

Oh, and not just the amps. The CDPs can drive headphones too provided they're sensitive enough. Moved the Marantz to my bedside table for quick listening before I sleep, or while I'm reading. Slightly better than the Creative Zen this way.

 

[Zeroblade]

I tried the RCA>1/4 adaptor method with an integrated amp. Results were... not good. You definitely need to use the headphone jack.

 

[Drosera]

Quote:

Originally Posted by pp312 /img/forum/go_quote.gif There have been threads about this before and the anecdotal evidence of owners is that 95% of integrated amps and receivers use a resistor off the speaker outlets. In fact the only ones that don't seem to be in the higher price bracket, so there's not much fear of those mythical 50c op amps behind your typical headphone jack.

This is true and creates a bit of a problem few people seem aware of. Stepping down the speaker output with a few resistors to make a headphone output gives you a headphone output with a rather high output impedance. Commonly the output impedance of such a headphone jack is around 200 ohm. This in turn means that using such an output with headphones that are less than, say, 250 ohm in (nominal) impedance is not such a great idea. Since the ability of an amplifier to control a headphone is for a large part determined by the difference in output impedance (amp) and headphone impedance.

EDIT: Linkies to older threads on the 'speaker amp for headphones'-subject:

http://www.head-fi.org/forums/f5/usi...ed-amp-329395/
http://www.head-fi.org/forums/f5/man...-jacks-338299/

 

[pp312]

Quote:

Originally Posted by ProtegeManiac /img/forum/go_quote.gif I use my NAD304; I haven't opened it up completely but last time I cleaned the insides I noted the headphone driver had a small PCB on it with some sort of shilding wrapped around it. I think it had an IC and definitely some caps, most likely a CMOY-type.

I wouldn't assume because there's a circuit board behind the headphone jack that there's an amp involved. There's always a small circuit board there, sometimes housing two resistors, sometimes four, and very occasionally a couple of small caps as well (not sure what they do). This doth not a Cmoy make. If you can actually see an IC I'll stand corrected, but somehow I doubt it (I've owned most of the NADS, though not that one).

 

[pp312]

Quote:

Originally Posted by Drosera /img/forum/go_quote.gif This is true and creates a bit of a problem few people seem aware of. Stepping down the speaker output with a few resistors to make a headphone output gives you a headphone output with a rather high output impedance. Commonly the output impedance of such a headphone jack is around 200 ohm. This in turn means that using such an output with headphones that are less than, say, 250 ohm in (nominal) impedance is not such a great idea. Since the ability of an amplifier to control a headphone is for a large part determined by the difference in output impedance (amp) and headphone impedance.

This is true in theory but in practice seems to have much less effect than you might suppose. The worst effect seems to be a slightly fuller bass, which is often subjectively beneficial. However, it would help a lot if we all used high impedance headphones.

I'm currently using Senn 650s with a Yamaha RX396 stereo receiver. The HP output impedance is in fact 330 ohms, which should suit the 300 ohm Senn down to the ground. And of course there's no question of this 50 watt amp not having enough current or whatever. Subjectively the sound is better than I've heard from any of the dozens of amps, integrated and dedicated, I've owned, not because the amp is inherently better but because I discovered almost by accident that the unique Yamaha Variable Loudness Control, used judiciously, can actually overcome the Senn veil more successfully than any aftermarket cable or tone controls. However, this is another story and shall be told another time.

 

[Drosera]

Quote:

Originally Posted by pp312 /img/forum/go_quote.gif This is true in theory but in practice seems to have much less effect than you might suppose. The worst effect seems to be a slightly fuller bass, which is often subjectively beneficial. However, it would help a lot if we all used high impedance headphones. I'm currently using Senn 650s with a Yamaha RX396 stereo receiver. The HP output impedance is in fact 330 ohms, which should suit the 300 ohm Senn down to the ground. And of course there's no question of this 50 watt amp not having enough current or whatever. Subjectively the sound is better than I've heard from any of the dozens of amps, integrated and dedicated, I've owned, not because the amp is inherently better but because I discovered almost by accident that the unique Yamaha Variable Loudness Control, used judiciously, can actually overcome the Senn veil more successfully than any aftermarket cable or tone controls. However, this is another story and shall be told another time.

Interesting, and I must say that it often appears it's simply a matter finding the right headphone-integrated amp synergy (which seems to be more tricky than with dedicated headphone amps). I can't say that I've had much luck in that department, any headphone I plug into my NAD C320, varying from 33 ohm Grados to 600 ohm Sextetts, sounds simply mediocre when compared with my dedicated amps.

By the way would that fuller bass also have consequences on the other end of the spectrum (less highs) due to a shift of the frequency response curve?

 

[googleborg]

oh talking about this I've almost finished my speakers out to headphone jack thing, it's trivially simple (enough to confuse me still hahaha) but i wanted to make it look nice and use good parts >_> can also swap out resistors, ooh yeah.

funny to see the old op-amp gem come up.
"Sure. Often their headphone amplifier part is quite cheap though (either basic Cmoy or transformed from speaker-amp to headphone friendly) and not very good sounding, but there are very good implementations too."

noooooo, every integrated I've opened has used 2watt (i think) resistors. there's bound to be some amps that can't use this method due to heat issues or some other reason, decent 2watt resistors may actually cost more than an op-amp but an opamp seems far more costly to design in what with it needing power and other components :/

to pp312, i am using a yamaha ax-396 (amp-alone version of the receiver) right now for my senns!

 

[Palpatine]

I had various Yamaha receivers that did a good job with even my higher impedance phones.

 

[linuxworks]

Quote:

Originally Posted by Currawong /img/forum/go_quote.gif No problem doing so. Quite often the built-in headphone socket in hi-fi amps is just connected to the speaker output via a resistor. The only downside is, speakers are low-voltage and high current, whereas headphones are high voltage and low current,

this is news to me. why do you say this?

how can you generalize like that?

only for high-z cans do you need 'higher voltage' and again, most decent home amps DO run high'ish voltage rails.

 

[pp312]

Quote:

Originally Posted by Drosera /img/forum/go_quote.gif Interesting, and I must say that it often appears it's simply a matter finding the right headphone-integrated amp synergy (which seems to be more tricky than with dedicated headphone amps). I can't say that I've had much luck in that department, any headphone I plug into my NAD C320, varying from 33 ohm Grados to 600 ohm Sextetts, sounds simply mediocre when compared with my dedicated amps.

I never cared for the C320 with my HD650, but oddly felt the C320BEE was better. In any case I wouldn't judge from just one amp, particularly the C320, which is known to have a rolled off top and slightly energised lower treble to compensate, giving it a unique sound signature.

Quote:

Originally Posted by Drosera /img/forum/go_quote.gif By the way would that fuller bass also have consequences on the other end of the spectrum (less highs) due to a shift of the frequency response curve?

Do you mean due to my use of the variable loudness control? This control increases both bass and treble, but its subjective effect is to make the 650 sound "leaner", removing the veil. I think this is because the bass boost is at a frequency outside the range of most music, whereas the treble boost is not. Boost from the treble control itself didn't work; it affected the midrange too much, giving a "reverb" like effect. The loudness control leaves the midrange unaffected. The best description of its effect is photographic: it sharpens and focusses the 650's sound.

 

[pp312]

Quote:

Originally Posted by googleborg /img/forum/go_quote.gif noooooo, every integrated I've opened has used 2watt (i think) resistors. there's bound to be some amps that can't use this method due to heat issues or some other reason, decent 2watt resistors may actually cost more than an op-amp but an opamp seems far more costly to design in what with it needing power and other components :/ to pp312, i am using a yamaha ax-396 (amp-alone version of the receiver) right now for my senns!

Yes, it's safe to say that virtually all commercial grade amps use the resistor solution, and to me that's a good thing. As I've said on other threads, if I buy a well-reviewed amp (and why buy anything else?) I want to be hearing the sound the reviewer praised, not an op-amp he didn't praise. In that sense op amps would be a fraud, giving the speaker user the benefit of all the amp designer's expertise and all the fine components he specified, but the headphone user something else entirely--without him being aware of it!

Re the ax-396, if you were using the 650 I'd say, start experimenting with the variable loudness immediately. Unfortunately I suspect it would have only a deleterious effect with the 555, which doesn't need slimming down. However I've used my receiver with both a 555 and 595 and the sound is just fine as is--very well balanced. Nice amp, nice phones, easily good enough for people who don't keep reading head-fi.

.

 

[Drosera]

Quote:

Originally Posted by pp312 /img/forum/go_quote.gif I never cared for the C320 with my HD650, but oddly felt the C320BEE was better. In any case I wouldn't judge from just one amp, particularly the C320, which is known to have a rolled off top and slightly energised lower treble to compensate, giving it a unique sound signature.

Oh, I experimented with a whole host of integrated amps, I just used the C320 as an example.

Quote:

Originally Posted by pp312 /img/forum/go_quote.gif Do you mean due to my use of the variable loudness control? This control increases both bass and treble, but its subjective effect is to make the 650 sound "leaner", removing the veil. I think this is because the bass boost is at a frequency outside the range of most music, whereas the treble boost is not. Boost from the treble control itself didn't work; it affected the midrange too much, giving a "reverb" like effect. The loudness control leaves the midrange unaffected. The best description of its effect is photographic: it sharpens and focusses the 650's sound.

What I actually meant is that a high output impedance usually has the effect of shifting a headphone's frequency response curve to the left, resulting in more (lower) bass and less highs (depending on where the headphone rolls off, of course). It sounds like you actually might be compensating for this effect by turning up the treble with the tone controls. (Not that there's anything wrong with that.

)