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Many AV Receivers/Stereo Integrated amps do NOT use opamp powered headphone jacks - Page 3

post #31 of 216
The whole thing is a big conspiracy, involving the forum veterans. They are getting paid by the amp makers to lead other members to buy their products!

When you pass the 3 year mark, or 5000 posts on head-fi, you will be offered a free amp from one of the amp makers if you push 3 or more amps on the newbies!
post #32 of 216
Quote:
Originally Posted by ingwe View Post
x2 My Bryston BP-25, by itself, drives headphones wonderfully--but it is transparent to a fault. According to bryston, the headphone output is the exact same signal fed to the power amp.
Well, if it's not transparent to a fault driving speakers as well, warmer headphones would probably do the trick. Speakers/headphones are probably a better place to color to taste, as it is almost impossible to avoid color there anyway.

Tim
post #33 of 216
My plan was to buy a dedicated headphone amp. I was also looking for a good speaker amp to drive my vintage Stax. I found a vintage NAD integrated amp at Goodwill. The headphone jack sounds very good to me. I've only heard dedicated headphone amps at meets, which is not a great environment for critical listening IMO, but for me, the NAD has reached the point of diminishing returns. I can't justify spending $500 on a dedicated amp when the NAD sounds so good. I'm sure some $500 amps will sound better, but not enough to justify the cost.

If this means I'm not an audiophile, that's fine with me. I've always believed in spending more money on the music than on equipment anyway. I think for some people here, that attitude is sacrilege

One more bit of head-fi sacrilege. One thing I like about integrated/pre amps is tone controls. I like to be able to give a little bass or treble boost to headphones that roll off. It's also nice to tone down treble that's a little bright.
post #34 of 216
Thread Starter 
Well pp312, I do listen to you. How to you think this thread started

People have have left Head-Fi because noobs called them elitists.

But if you wander around to other places on the web (Hydrogen Audio for example) you'll find people who left Head-Fi because they purchased expensive headphone amps and were shocked by how little "sound quality" improvement they heard. They felt like suckers and built up a complete distrust of this place.

I'm aware of some of the technical arguments against resistored off headphone jacks. But theoretical technical superiority does not mean practical real-worrd superiority. Granted "practical" on a forum like this is a subjective measure, but there are a number of people who hear little to no improvement with a dedicated headphone amp compared to their integrated, and for them that is a practical reality. Their voices have been completely drowned out by plethora of voices that constantly say "You SHOULD be hearing a difference because everybody says it exists." So much has been repeated on this forum by people who say things because everybody else says it. It's like that game I played as a child. Everybody sits in a circle and a whispered sentence starts at one end and goes around the room until something completely different comes out the other end.

And yes, I'm practical when it comes to my wallet. If I can get a Yamaha AV receiver for $300 that gives me 98% of what a $1000 headphone amp/DAC does, I'm not all that interested in getting that dedicated headphone amp/DAC combo. After all, "Sound Quality" is a subjective measure. 2% might be nothing at all for me, although I suppose if hundreds of people told me it was a big deal I might believe it. Personally I'd rather spend that $700 on something else - perhaps on the extra electricity costs of that AV receiver and a set of speakers powered by that receiver.
post #35 of 216
Thread Starter 
Quote:
Originally Posted by greggf View Post
I suspect the answer may somehow be in this obscure post by a Head-Fier named Joe Bloggs way back in 2003:


"Well, the headphone output on many amplifiers is just connected to the speaker amp via a high resistance resistor. It would cost them just a little more to build a proper resistor network (like the Grado headphone adapter) with low output impedance. . . "
Well that brings up an interesting point. If a proper resistor network (I assume he means a series parallel arrangement) gives headphones what they want, why not recommend that on this forum that instead of a dedicated headphone amp? It could probably be built one for $1. That's a lot cheaper than any headphone amp and hey, if it works as well...

What you quoted doesn't exactly indicate a problem with using resistors versus a dedicated headphone amp. It actually supports the resistor argument to some degree.
post #36 of 216
Quote:
Originally Posted by odigg View Post
Well that brings up an interesting point. If a proper resistor network (I assume he means a series parallel arrangement) gives headphones what they want, why not recommend that on this forum that instead of a dedicated headphone amp? It could probably be built one for $1. That's a lot cheaper than any headphone amp and hey, if it works as well...

What you quoted doesn't exactly indicate a problem with using resistors versus a dedicated headphone amp. It actually supports the resistor argument to some degree.
It's a matter of "properly implemented". Single resistors to drop current will set the output impedance and create a voltage divider with the headphones altering their frequency response (changing how they sound).
post #37 of 216
Quote:
Originally Posted by FallenAngel View Post
It's a matter of "properly implemented". Single resistors to drop current will set the output impedance and create a voltage divider with the headphones altering their frequency response (changing how they sound).
Any clue what "properly implemented" means? Because if it's not prohibitively expensive, it would be a pretty safe bet that the better manufacturers might be doing it. To not do so would be to needlessly negate all the work they put into designing and building a good sounding amp. I don't doubt that a single resistor is just slapped in there in some cases. I seriously doubt it is done in all. Would bet against it with brands that are pushing at the edge of high end, like NAD, Marantz and Cambridge Audio. If I know what to ask, I will.

Tim
post #38 of 216
Quote:
Originally Posted by senns&nonsense View Post
It is just ridiculous that this sort of value is not only not celebrated here, but insultingly dismissed as the musings of people who are mentally unbalanced and cannot afford more.
Not only ridiculous but disgusting. I'm still shocked that someone could burst into a thread like this and insult all the contributors for...well, contributing. The phrase appallingly arrogant springs to mind. Or was the whole post just tongue in cheek? Maybe I missed something.
post #39 of 216
Quote:
Originally Posted by odigg View Post
Well pp312, I do listen to you. How to you think this thread started
And a fine thread it is, to be sure, to be sure.

Even with the negative intrusions.
post #40 of 216
I gotta call BS to the emails that were sent by the manufacturers.
Unless they have changed things drastically in the last two or three years, virtually every Denon AVR that I've looked at has an extremely simple opamp circuit with almost no balls powering the headphone output.

I've torn into dozens of Denons, Yamahas, NADs, Sonys, and Onkyos and looked at the schematics of many others that I haven't actually torn apart. Most every one that I've seen uses some form of opamp circuit, usually with weak power legs and very little capacitance.

One exception was a cheap stereo receiver from Sony, the STR-DE185 I think. It used resistors from the main amp output. We still have it for bedroom use, and it actually powers my Senn 580s pretty darn good. Much better than the Denon and Onkyo AVRs that we've had.
post #41 of 216
Quote:
Originally Posted by tfarney View Post
Well, if it's not transparent to a fault driving speakers as well, warmer headphones would probably do the trick. Speakers/headphones are probably a better place to color to taste, as it is almost impossible to avoid color there anyway.

Tim
Neutrality (what ever that ::really:: means) can be quite disconcerting. But that's what I strive for. Otherwise over time everything starts sounding the same (relatively).
post #42 of 216
Quote:
Originally Posted by billbillw View Post
I gotta call BS to the emails that were sent by the manufacturers.
Unless they have changed things drastically in the last two or three years, virtually every Denon AVR that I've looked at has an extremely simple opamp circuit with almost no balls powering the headphone output.

I've torn into dozens of Denons, Yamahas, NADs, Sonys, and Onkyos and looked at the schematics of many others that I haven't actually torn apart. Most every one that I've seen uses some form of opamp circuit, usually with weak power legs and very little capacitance.

One exception was a cheap stereo receiver from Sony, the STR-DE185 I think. It used resistors from the main amp output. We still have it for bedroom use, and it actually powers my Senn 580s pretty darn good. Much better than the Denon and Onkyo AVRs that we've had.
I know my 80s vintage NAD 3155 uses resistors. Says so on the schematic and it'll drive anything out of the headphone jack. I have a pair of AT-706 electrets that a previous owner modified with a TRS plug. The NAD's headphone jack drives it without distortion. Considering these are usually run out of speaker outs with a transformer, the headphone jack is pretty powerful. I also don't have any low impedance headphones, so I don't have the impedance mismatch that is mentioned above.

Edit: I can understand why a 5.1 or 7.1 AVR amp would use op amps. I don't understand why a 2 channel amp would unless they thought the op amps would be better. I doubt anyone would listen to headphones out of a 5.1 or 7.1 system and expect it to sound anything like listening to speakers.

Edit2: I would really like to second the request for what to look for to know if the resistors off of the speaker outs are implemented correctly. I have the schematic for my NAD and I'd like to know what to look for.
post #43 of 216
No offense, but could you offer any evidence of this other than your word against that of the people who designed and built the amps in question?

Tim

Quote:
Originally Posted by billbillw View Post
I gotta call BS to the emails that were sent by the manufacturers.
Unless they have changed things drastically in the last two or three years, virtually every Denon AVR that I've looked at has an extremely simple opamp circuit with almost no balls powering the headphone output.

I've torn into dozens of Denons, Yamahas, NADs, Sonys, and Onkyos and looked at the schematics of many others that I haven't actually torn apart. Most every one that I've seen uses some form of opamp circuit, usually with weak power legs and very little capacitance.

One exception was a cheap stereo receiver from Sony, the STR-DE185 I think. It used resistors from the main amp output. We still have it for bedroom use, and it actually powers my Senn 580s pretty darn good. Much better than the Denon and Onkyo AVRs that we've had.
post #44 of 216
Not much to add to the discussion but here is a link with some info on resistor networks.

Meier Audio
post #45 of 216
Quote:
No offense, but could you offer any evidence of this other than your word against that of the people who designed and built the amps in question?

Tim
I have the service manuals for more than a dozen modern AVR receivers, integrated amps, preamps, etc. Obviously I can't post them all, but maybe I can cut out a section of a few and turn them into jpeg images. Depends whether the manufacturers put copy locks on the files. I'll check over the weekend.
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