[tfarney]

I keep reading these comments, in various threads, about 650s that basically say that without significant power behind them they are blubbery, indistinct, dull...you get the picture. There are even folks who say that a good portable amp isn't enough to drive them properly. Yet I'm sitting here listening to my 580s, plugged straight into my Apple iBook, and while I know it could be better (and will be soon), I'm simply not having the problems they describe. Bass is crisp and powerful, mids are present. Trebles are quite nice. So I guess the question is, is there some reason why the 300 ohm load on my 580s would behave so differently than the 300 ohm load on the 650s? Or if I plugged them into a high-powered, high-current amp would the heavens open like door?

Tim

 

[vcoheda]

580/600 quite different from 650.

 

[FallenAngel]

I don't think the HD650 are really "harder" to drive than HD580/HD600, they just sound different.

Listen with a good amp and then try going back to straight out of iBook. You'll notice the effects clearly. Yes, they do need an amp to sound right (not just nice, but seriously good).

 

[zillac]

Aren't they 600ohm?

IMO You need a good amp for both 580s and 650s to sound good.
But, everyone just hear different things; the best thing to do, is listening to them and do a comparison by yourself. Then decide if a amp is needed.

 

[PFKMan23]

Quote:

Originally Posted by zillac /img/forum/go_quote.gif Aren't they 600ohm?

The nominal impedance of all three are 300 ohm.

 

[LeChuck]

Quote:

Yet I'm sitting here listening to my 580s, plugged straight into my Apple iBook, and while I know it could be better (and will be soon), I'm simply not having the problems they describe. Bass is crisp and powerful, mids are present. Trebles are quite nice. So I guess the question is, is there some reason why the 300 ohm load on my 580s would behave so differently than the 300 ohm load on the 650s? Or if I plugged them into a high-powered, high-current amp would the heavens open like door?

I just tried doing this out of a friend's Macbook Pro, with HD 580's and HD 650's. I can drive both of them past audible listening levels, but both of them sound (as compared to how they sound when amped) bad at all levels. Frankly, I think the 300ohm Sennheiser cans are one of the best cases for headphone amping.

When you get your new amp, listen to it for a few days and then switch back to your iBook. It won't be the same, trust me. You'll still be able to make them plenty loud, but it just won't be the same.

Also there's one other thing to conside, and I don't mean this in a snobbish way, but if you've been listening to unamped HD 580's you're probably still ignorant of how good they can sound. For 99.999% of the non Head-fi population, a pair of unamped HD 580's are going to sound amazing. Most people think Skullcandy sounds amazing, and they're not wrong in saying so, but they simply haven't experienced anything better.

The scale by which you judge things expands when you try something better, and as a result pushed everything else down. You might be used to driving a BMW, which are great cars and handle well, but if you take a trip around the block in a Lamborghini LP640, you're going to have a new benchmark and as a result your feelings about how good the BMW actually is will have shifted.

The same can be said of amps. My first ever Head-fi amp experience was a pair of HD 580's and a Headroom Airhead. I thought it was amazing and it blew me out of the water. I never "heard" any of the things that people were complaining about, just as you don't. I started upgrading, year after year, until eventually I had several thousand dollars invested in a fairly serious setup. It was a gradual ascention, but a few weeks ago I plugged in my VERY old Airhead, into the same source I was using back in the day, and threw on a pair of HD 580's and was totally underwhelmed to say the least. (That's not a jab at Headroom, they make great products and I'm listening to a 2007 Total Bithead as I write this).

The point I'm making, is this: your relative standards of what's good and what's not are going to change as you progress in this hobby. You might not experience night/day differences between each step up the scale, but if you go back a few steps, you'll definitely notice the difference.

 

[Jaska]

Not too long ago, I spent quite a while in a Hi-Fi shop in Tampere (nicest city on earth

) listening to some of my own CDs via harman-kardon's HD 970 CD player and HK 970 integrated amp with the HD-650. While some would probably not look too highly on that rig, as someone quite used to the HD-580's sound from various sources, I would still comment that the 650s were an absolute delight to my ears. I'm still surprised I was able to leave the store without those headphones, but that wasn't the purpose of my shopping that day.

While I don't have further experience with the HD-650, and don't know much about the overall quality of the headphone circuitry in the HK 970, I still think this setup sounded amazing.

 

[Pricklely Peete]

Well said LeChuck.......that is bang on....

 

[sejarzo]

Impedance and/or current isn't the real issue with the 300 ohm Senn's--it's sensitivity and voltage.

In theory, a higher impedance would be easier to drive, but the 300 ohm Senns require about 5 times the voltage for a given SPL versus the 50 ohm HD595's. Someone asked some questions about that recently, and I did some calculations that are posted here:

http://www.head-fi.org/forums/f4/low...7/#post3750485

While the HD580/600/650 require more voltage and a bit more power than the HD595 at the same SPL, they don't require more current--the increased sensitivity of the HD595 doesn't offset the fact that its lower impedance makes it draw much more current.

As I noted in the linked post, the 3.7V rechargeable Li-Ion batteries in most DAP's limit the output voltage to a point where DAP's just can't handle the peaks with the 300 ohm Senn's.

 

[tfarney]

Quote:

Originally Posted by Jaska /img/forum/go_quote.gif Not too long ago, I spent quite a while in a Hi-Fi shop in Tampere (nicest city on earth ) listening to some of my own CDs via harman-kardon's HD 970 CD player and HK 970 integrated amp with the HD-650. While some would probably not look too highly on that rig, as someone quite used to the HD-580's sound from various sources, I would still comment that the 650s were an absolute delight to my ears. I'm still surprised I was able to leave the store without those headphones, but that wasn't the purpose of my shopping that day. While I don't have further experience with the HD-650, and don't know much about the overall quality of the headphone circuitry in the HK 970, I still think this setup sounded amazing.

Isn't the headphone circuitry in most receivers and integrateds simply the amp circuitry with the output reduced through a nest of resistors? It would seem like it would be pointless, and more expensive, for it to be anything more (or less). I've asked this question here before and I'm not sure I got an answer. I mean I get that the headphone out from a CD player might be a cheap op amp, but from an integrated, receiver, or even a preamp, that just wouldn't make any sense. Am I missing something?

This much I do know - I have a cheap digital receiver in my den that drives my Senns better than the iBook and better than my Airhead.

And LeChuck - thanks. Very good answer.

Tim

 

[sejarzo]

Quote:

Originally Posted by tfarney /img/forum/go_quote.gif Isn't the headphone circuitry in most receivers and integrateds simply the amp circuitry with the output reduced through a nest of resistors? It would seem like it would be pointless, and more expensive, for it to be anything more (or less). I've asked this question here before and I'm not sure I got an answer. I mean I get that the headphone out from a CD player might be a cheap op amp, but from an integrated, receiver, or even a preamp, that just wouldn't make any sense. Am I missing something?

Yes, you are missing something.

Almost all amps that have a headphone output use an opamp circuit to do that; Marantz CD players (and maybe their integrateds, too?) use a discrete module. Bryston preamps also use a discrete headamp design, separate from the stage that drives the regular RCA outputs.

The output stages in some preamps (or CD players, for that matter) aren't designed with an extremely low output impedance (meaning, the capability to keep putting out the same current as the output voltage increases.) The presumption is that they will be driving inputs with load impedances of 22.1 to 47 kohms, which requires very little current.

That being said, you can drive most 300 ohm cans directly from preamps or CD player outputs (with an RCA plug-to-TRS jack adapter cable.) But when you get down to 32 ohm cans, you're asking that output stage to put out 700 to 1500 times the current as it would when driving a power amp input!

A nest of resistors would be more expensive than a little opamp circuit, anyway, and just generate a lot of heat for no reason.

 

[tfarney]

Quote:

Originally Posted by sejarzo /img/forum/go_quote.gif Yes, you are missing something. Almost all amps that have a headphone output use an opamp circuit to do that; Marantz CD players (and maybe their integrateds, too?) use a discrete module. Bryston preamps also use a discrete headamp design, separate from the stage that drives the regular RCA outputs. The output stages in some preamps (or CD players, for that matter) aren't designed with an extremely low output impedance (meaning, the capability to keep putting out the same current as the output voltage increases.) The presumption is that they will be driving inputs with load impedances of 22.1 to 47 kohms, which requires very little current. That being said, you can drive most 300 ohm cans directly from preamps or CD player outputs (with an RCA plug-to-TRS jack adapter cable.) But when you get down to 32 ohm cans, you're asking that output stage to put out 700 to 1500 times the current as it would when driving a power amp input! A nest of resistors would be more expensive than a little opamp circuit, anyway, and just generate a lot of heat for no reason.

Thanks Sejarzo.

Tim

 

[QQQ]

Quote:

Are HD650s a lot harder to drive than HD580s?

No.

 

[boomana]

Yes and no. No, if you're talking about volume. You can get them louder than you would ever want fairly easily. Yes, if you're talking about sound quality. I have both the 650s and 600s (I had the 580s a couple years ago) and have tried both with a variety of amps. The 650s can sound bass-heavy in a blanketed way, and slower overall when not matched with a amp that drives them well. The 600s and 580s don't really have this problem to the same degree, are a bit more forward in general, and sound better with a variety of amps. The 650s are pickier, and responded better to fewer amps, but I've heard them sound quite good with both tube and solid states amps, ranging from $400ish-10,000. Giving them enough power is only part of it. In order to bring out their mid and upper range refinement, and have the bass be tight, clean and fast requires some synergy.