[Dreadhead]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif Say, I'm just curious from your signature line -- what are the minuses of balanced headphones?

Sorry a bit of tech geekery.... They have both plus and minus signal paths instead of plus and ground on SE phones.

The only minus I've found is that fact that the plugs are heavy and you have to be more careful with them especially if you have wooden furniture and or headphones.

 

[schaqfu]

Quote:

Originally Posted by Dreadhead /img/forum/go_quote.gif Sorry a bit of tech geekery.... They have both plus and minus signal paths instead of plus and ground on SE phones. The only minus I've found is that fact that the plugs are heavy and you have to be more careful with them especially if you have wooden furniture and or headphones.

That's damn funny. I should have picked up on it. I love puns.

 

[Dreadhead]

Quote:

Originally Posted by Dreadhead /img/forum/go_quote.gif Eric, I checked your numbers and they are right. What I would like to further point out though is that if you take the currents calculated with the ideal amplifier and then calculate the sensitivities of the phones (dB/mw) at the various frequencies you used (using the data from Headroom and the fact they use 90dB at 1kHz as '0'db. I get the following bumps dB changes: Freq, Db Change from ideal (0 dB SPL at 1kHZ) 20-10 802 6001 10000 6000-2 2000-2 As you can see this is well within the usual variation of these headphones over the audible range (Just look at the response curve) (Who can hear 20kHZ and 20 Hz?). So even though your numbers are correct they really don't change the actual sound output of the headphones that much. So maybe the added power etc is outweighing this. Just my two cents, Chris

^^^^^ I was wrong... sorry.

The numbers are:

20-4.7
8010.52214876
6003.2475
10000
6000-1.388888889
20002.153061224

The frequency response is definitely skewed towards the bass which probably is much of the effect we are seeing when we put the balanced phones on the DAC1.

 

[kool bubba ice]

Quote:

Originally Posted by eweitzman /img/forum/go_quote.gif I don't think my 650s sound very good with the DAC1's headphone amp unless the volume is turned up quite a bit. Then I'm really very pleased with the sound. Since I like to listen to music fairly loud (90-95dbC peaks), this suits me fine. If I was driving them balanced from the XLR line outputs and got a 3db bass boost and 1db treble boost compared to the mids, it would certainly sound better to me at lower listening levels. This is exactly what the "loudness" compensation circuits in older preamps do, BTW. These circuits raise the bass and treble levels at lower listening levels, compensating for our ears' lower sensitivity at the frequency extremes. (See Fletcher-Munson equal loudness contours is you're not familiar with this.) But I don't want my headphones to have this distorted frequency response all the time. If I really wanted the boosts at lower levels at times, I'd use a loudness circuit or tone controls or an equalizer. My goal is to have phones that provide the most flat and undistorted playback possible to reveal what's coming from the source. I suppose if I always listened at low levels, going balanced from the XLR line outputs would be an acceptable alternative. - Eric

I will grant you the bass boost & treble.. Thats seems logical enough.. That can make it seem better..But what about the better detail, clarity, speed, & openess I noticed? My SA5000 are only 70 Ohms.. They are balanced.. I don't notice a bass boost at all. The bass is improved, but it more tight & full sounding.. & I'd be hard pressed if I even heard a difference using my 340's balanced with my DAC1?? I think we can both agree that the DAC1 doesn't make a optimal balanced headphone amp..Which I knew from the start.

 

[kool bubba ice]

Quote:

Originally Posted by schaqfu /img/forum/go_quote.gif I'm inclined to suspect the same thing, but like you I also haven't made a balanced listening test with a true balanced amp, so I won't know until I do. What I'm having trouble parsing is whether people think the balanced drive actually changes the quality and character of the audio signal (people talk about better bass, more separation between notes, better soundstaging, etc., etc.) or whether it's all 100% a function of reducing noise in the signal (cross-talk and RFI). If it's just about reducing noise, I can understand the value proposition, but it seems like it wouldn't have the monstrous impact most adherents claim it does. Confusing.

Who claimed monstrous impact?

 

[eweitzman]

Quote:

Originally Posted by kool bubba ice /img/forum/go_quote.gif But what about the better detail, clarity, speed, & openess I noticed?

That's most likely due to the treble boost. Very subtle boosts, even 0.1db, can have these effects. I'm always wary of things that increase detail to make sure that there is truly more information coming through, and not just extra highlighting of what's already there. Good phones can let you hear this type of stuff in other components, but who's keeping tabs on the phones?

Quote:

Originally Posted by kool bubba ice /img/forum/go_quote.gif My SA5000 are only 70 Ohms.. They are balanced.. I don't notice a bass boost at all. The bass is improved, but it more tight & full sounding..

I don't even know what an SA5000 is, but I'll try to answer.

The "full sounding" part could be bass boost. You be the judge.

By way of explanation, there will be more variation in the frequency response as either the output (amp) impedance goes up or the input (phone) impedance goes down. So initially the SA5000 should show more variation with the DAC1 XLR line outputs than the 650s (everything else being equal). But if the impedance curve of these phones is flatter than the 650s, the variation would be less. All you can do is run the numbers to find out what the resulting frequency response will be.

Look at it this way: if the impedance of the phones (or any load) is dead flat, then the output impedance won't cause any frequency distortion at all, just a drop in level. Speaking of which, with 70 ohm phones on 60 ohm (DAC1) outputs, you're dumping half the power across the 60 ohm resistors in the DAC1! Turn it up to stay even...but sensitivity may come in to play and you might not have to turn them up so much.

Quote:

Originally Posted by kool bubba ice /img/forum/go_quote.gif I think we can both agree that the DAC1 doesn't make a optimal balanced headphone amp..Which I knew from the start.

Absolutely. I hope that we can also agree with Elias' comments about what to expect with phones on the XLR line outputs now. He's one smart cookie and a zen master of cool-headedness to boot!

BTW, you'd have the same type of frequency distortion with balanced phones on the RCA line outputs, only it would be about half as much because the output impedance is half that of the XLRs. But then you lose the whole separated/clean ground thing which is a main point for balanced phones if I understand correctly.

- Eric

 

[eweitzman]

Quote:

Originally Posted by slwiser /img/forum/go_quote.gif [size=x-large] Good Stuff [/size] [size=xx-small]I have attempted to communicate some of this myself with failure. Your doing a much better job of it than I ever did.[/size]

Thanks, slwiser. In the hifi (instead of headfi) world, you get to deal with speaker load and output impedance issues, especially with tube amps. But I moved on from tubes and high efficiency speakers a few years ago.

- Eric

 

[kool bubba ice]

Quote:

Originally Posted by eweitzman /img/forum/go_quote.gif That's most likely due to the treble boost. Very subtle boosts, even 0.1db, can have these effects. I'm always wary of things that increase detail to make sure that there is truly more information coming through, and not just extra highlighting of what's already there. Good phones can let you hear this type of stuff in other components, but who's keeping tabs on the phones? I don't even know what an SA5000 is, but I'll try to answer. The "full sounding" part could be bass boost. You be the judge. By way of explanation, there will be more variation in the frequency response as either the output (amp) impedance goes up or the input (phone) impedance goes down. So initially the SA5000 should show more variation with the DAC1 XLR line outputs than the 650s (everything else being equal). But if the impedance curve of these phones is flatter than the 650s, the variation would be less. All you can do is run the numbers to find out what the resulting frequency response will be. Look at it this way: if the impedance of the phones (or any load) is dead flat, then the output impedance won't cause any frequency distortion at all, just a drop in level. Speaking of which, with 70 ohm phones on 60 ohm (DAC1) outputs, you're dumping half the power across the 60 ohm resistors in the DAC1! Turn it up to stay even...but sensitivity may come in to play and you might not have to turn them up so much. Absolutely. I hope that we can also agree with Elias' comments about what to expect with phones on the XLR line outputs now. He's one smart cookie and a zen master of cool-headedness to boot! BTW, you'd have the same type of frequency distortion with balanced phones on the RCA line outputs, only it would be about half as much because the output impedance is half that of the XLRs. But then you lose the whole separated/clean ground thing which is a main point for balanced phones if I understand correctly. - Eric

Yes, Elias is bright, but has a very narrow minded view when it comes to balanced headphones in general.. What you say is reasonable & have no problem with it.. I still feel they sound better balanced, albiet treble bass boost or not.. But why didn't going balanced effect my AKG 340's? I don't notice any differences from SE DAC1 amp & the DAC1 xrl outs? They are 400 ohms.

 

[eweitzman]

Quote:

Originally Posted by kool bubba ice /img/forum/go_quote.gif But why didn't going balanced effect my AKG 340's? I don't notice any differences from SE DAC1 amp & the DAC1 xrl outs? They are 400 ohms.

I googled for AKG 340 (K-340 I believe) and see they're electrostatics. Not much info out there though so I'm not clear on what they actually are. But if electrostats, they must have a dedicated amp, no? If they have a dedicated amp, and the amp's input impedance is 400 ohms, it's almost certainly a FLAT 400 ohms and the frequency response at the amp's inputs wouldn't be affected by the output impedance of the source. Can you tell me more about them?

BTW, there's a pair for sale in Canada for $150 if anyone is interested.

- Eric

 

[HeadphoneAddict]

Quote:

Originally Posted by eweitzman /img/forum/go_quote.gif I googled for AKG 340 (K-340 I believe) and see they're electrostatics. Not much info out there though so I'm not clear on what they actually are. But if electrostats, they must have a dedicated amp, no? If they have a dedicated amp, and the amp's input impedance is 400 ohms, it's almost certainly a FLAT 400 ohms and the frequency response at the amp's inputs wouldn't be affected by the output impedance of the source. Can you tell me more about them? BTW, there's a pair for sale in Canada for $150 if anyone is interested. - Eric

I thought they were a dual driver setup with ribbon tweeter?