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Speaker amps for headphones - Page 62

post #916 of 2754

Since we're on the subject of tubes:

 

http://ifi-audio.com/en/iTube.html

 

Reviewers have used it with headphones too. 

post #917 of 2754

A few days back, I had said that I would experiment with the Energizer XP8000 and the MG3.   I just posted a summary of my battery trials to date over on the AudioCircle thread (for anyone who has not yet tired of reading my dissertations on battery usage.  

 

(Hey, even I am getting tired of this topic!  LOL  But I think I've found my end game power source, so there's light at the end of this tunnel, for sure.)

 

http://www.audiocircle.com/index.php?topic=108242.msg1256542#msg1256542

 

Mike

post #918 of 2754

Mike:

 

Sorry to say this man, but I think for you there is no end game when it comes to batteries.  Batteries are constantly improving, and let's face it... you're a battery junkie...tongue.gif.

 

Of course I'm glad you are, because I've learned a ton from you on the subject.  And I'm another of those who is going to go with the ezpz answer.  I'll be adding the Energizer XP18000 to camelcamelcamel, hoping it drops some from $160... which is a pretty steep price given that the Millenia works just fine plugged in to the AC adapter...

post #919 of 2754
Quote:
Originally Posted by Gary in MD View Post

Mike:

 

Sorry to say this man, but I think for you there is no end game when it comes to batteries.  Batteries are constantly improving, and let's face it... you're a battery junkie..tongue.gif.

 

Of course I'm glad you are, because I've learned a ton from you on the subject.  And I'm another of those who is going to go with the ezpz answer.  I'll be adding the Energizer XP18000 to camelcamelcamel, hoping it drops some from $160... which is a pretty steep price given that the Millenia works just fine plugged in to the AC adapter...

 

Haha!  My name is Mike.  And I am a battery junkie.  There.  I said it.  tongue.gif

 

Actually, I'm just a geek engineer and gadget freak.  I "go deep" on everything that interests me (which just happens to be batteries, at the moment...  and uh... yesterday, and the day before that...)

 

LOL

 

I'll be done investigating batteries for the MG3 when I've finished building my HM-801 >  MG3 > LCD-2 "travel rig" (in the HPRC 2400F case). Photos will follow, eventually.

 

By the way, I've got a $150 alert set on camelcamelcamel, too!  biggrin.gif

 

Mike

post #920 of 2754

Mike:

 

When I searched camelcamelcamel for the XP18000, it came back with 4 pages of results, including many that appear to be better deals than the Energizer.  Jan had warned me earlier that many of these portable chargers had internal circuitry that would compromise the sound of the Millenia.  Is there a way to tell which ones are likely okay, and which ones aren't?

 

How about this one, for instance:

 

http://www.amazon.com/Intocircuit%C2%AE-26000mAh-External-Capacity-Notebooks/dp/B00BB5VQCE?SubscriptionId=AKIAJ7T5BOVUVRD2EFYQ&tag=camelbrowser-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00BB5VQCE

post #921 of 2754
Good find Gary!

I'd forgotten about these. They're actually made by Anker and if my Anker Astro3 is of comparable quality, I wouldn't hesitate to buy this version:

http://www.amazon.com/Anker-Ultra-High-Multi-Voltage-Notebooks-Compatible/dp/B00B45EOYS

Regarding Jan's warning, there's no way to know for sure without buying and testing it, but aside from charging circuitry that's not involved when unplugged from an AC outlet, my Energizer XP8000 and Anker Astro3 are both dead silent, sonically and externally, on multiple amps and DACs (DACport, DACport LX, Stepdance, PB2, DACmini CX, and now, the MG3).

I can't be sure, but I believe they achieve different voltages at multiple ports simultaneously, not through switch-mode technology, but rather by simple combinations of parallael and serial arrangement of their cells. When you tap the 19V port, you're seeing all five cells in series, but you can simultaneously tap the 5V port, for example, which sees either two cells in series -or- a quartet of cells in series and parallel. 12V ports see three cells in series. That's all that's happening in those boxes when they're not on the charger. Simple... Noiseless...

Again, somebody has to buy one and test it, to know for sure. I'm just conjecturing, here, but for the Anker Astro Pro 2 and Energizer XP18000A at least, the performance of their smaller siblings are very encouraging.

And the Anker's price is certainly better!

:-)

Mike
Edited by zilch0md - 9/1/13 at 11:44pm
post #922 of 2754

Anker Astro Pro 2

 

 

 

 

 

Source: http://media-mixture.de/technik/anker-astro-pro2-im-test-externer-akku-mit-20-000mah-fur-notebook-und-tablet/

I want one!
 

 

Mike


Edited by zilch0md - 9/2/13 at 7:51am
post #923 of 2754

Next installment in my MG3 saga....  

On advice of several more experienced than I, I investigated lower supply voltage.  On hand was a 13.8 VDC linear (high output capacitance = very well filtered) power supply.  Coupling this to the MG3 was an interesting sonic adventure.

 

But before I get to that, lets talk about break in... I've been running the amp into a purely resistive load for the last 40 hours or so... Gone is that dramatic (>10 dB) enhancement of frequencies above 2 kHz.  Bass is more filled out.  Substantially.  Not just psychosomatic, either, by the way.  The difference in frequency response is clearly apparent in frequency response measurements.  I'll also add that, from a physics point of view, I'm sure I don't understand this "break-in phenomenon."  With a Class D amplifier... What is changing?  What is the basis for the change in frequency response?  Warm up is one thing... Break in?   Anyway...  Someone more well versed in electrical theory than I will have to tackle that one... Out of my league, for sure!

 

So, 13.8 VDC operation.  Based on a few others experiences, 13.8 VDC is probably too low for that optimal balance of gain reduction and "fullness."  I miss the fullness of the bass, especially given that the highs are still sharp.  The lack of bass response was distracting, and less overall satisfying sound, so I'm back on 24 V from the stock charger.  

 

Hiss (remember, I'm back on 24 VDC, I'm using Flac>Gungnir>MG3>HE-6) is gone.  Maybe its a combination of burn in, some tinnitus and the fan in my PC, but I'm not hearing any hiss from the MG3.  Take that for what its worth... YMMV, etc...

 

Right now, I'm listening to Muse, The 2nd Law in high res.  MG3 dial is up about 10:30 or so... Sounds very good.  Bass response is ever so slightly restrained.  Not veiled... Less full.  Not fully fleshed out.  Maybe its bass extension.  Maybe its a tad bit of resolution missing.  Still a bit of high frequency enhancement with respect to the F1.  I wouldn't call highs "piercing", but overly bright for my ears.  I do still reach for the volume control to turn it down during bright passages.

 

Let me temper the above observations with this: the Millenia is an outstanding amp.  If I were not A/B-ing against what I consider to be a pretty decent couple of amplifiers (First Watt F1 and Parasound HCA-1000A) I'd probably never notice the fairly subtle differences.  If I needed a portable rig, this would be a clear winner.

 

Going to let it run overnight, for whatever that's worth... and look into lower source voltage input.  

 

Which reminds me: I did do some quick measurements out of Gungnir... Most of the time I saw less than 800 mV RMS, loud passages got up to 1.2 V RMS for short periods(100ms windows).  

 

Happy Labor Day...

 

-michael

post #924 of 2754
Excellent stuff, Michael! You're such a scientist, for real.

As I've posted previously, not having taken measurements as you have, I'm experiencing a similar break-in phenomenon with the MG3. 24V sounds best now (MG3 > 8-Ohm SM45), where previously, 15V was the winner. And the hiss I had heard at 24V is gone. I'm not logging the hours for the MG3, but I'm easily at about 50 now.

Thanks for the great feedback (and disciplined methodology),

Mike
post #925 of 2754
Quote:
Originally Posted by zilch0md View Post

Anker Astro Pro 2



I want one!



Mike

 

Of course you want one... it's a battery...

post #926 of 2754

Exactly!  

 

Precious batteries!  

 

Hahaha!  

 

But I'm going to wait for you to review this one.  

beerchug.gif

post #927 of 2754
Quote:
Originally Posted by potterma View Post

Next installment in my MG3 saga....  

On advice of several more experienced than I, I investigated lower supply voltage.  On hand was a 13.8 VDC linear (high output capacitance = very well filtered) power supply.  Coupling this to the MG3 was an interesting sonic adventure.

 

But before I get to that, lets talk about break in... I've been running the amp into a purely resistive load for the last 40 hours or so... Gone is that dramatic (>10 dB) enhancement of frequencies above 2 kHz.  Bass is more filled out.  Substantially.  Not just psychosomatic, either, by the way.  The difference in frequency response is clearly apparent in frequency response measurements.  I'll also add that, from a physics point of view, I'm sure I don't understand this "break-in phenomenon."  With a Class D amplifier... What is changing?  What is the basis for the change in frequency response?  Warm up is one thing... Break in?   Anyway...  Someone more well versed in electrical theory than I will have to tackle that one... Out of my league, for sure!

 

So, 13.8 VDC operation.  Based on a few others experiences, 13.8 VDC is probably too low for that optimal balance of gain reduction and "fullness."  I miss the fullness of the bass, especially given that the highs are still sharp.  The lack of bass response was distracting, and less overall satisfying sound, so I'm back on 24 V from the stock charger.  

 

Hiss (remember, I'm back on 24 VDC, I'm using Flac>Gungnir>MG3>HE-6) is gone.  Maybe its a combination of burn in, some tinnitus and the fan in my PC, but I'm not hearing any hiss from the MG3.  Take that for what its worth... YMMV, etc...

 

Right now, I'm listening to Muse, The 2nd Law in high res.  MG3 dial is up about 10:30 or so... Sounds very good.  Bass response is ever so slightly restrained.  Not veiled... Less full.  Not fully fleshed out.  Maybe its bass extension.  Maybe its a tad bit of resolution missing.  Still a bit of high frequency enhancement with respect to the F1.  I wouldn't call highs "piercing", but overly bright for my ears.  I do still reach for the volume control to turn it down during bright passages.

 

Let me temper the above observations with this: the Millenia is an outstanding amp.  If I were not A/B-ing against what I consider to be a pretty decent couple of amplifiers (First Watt F1 and Parasound HCA-1000A) I'd probably never notice the fairly subtle differences.  If I needed a portable rig, this would be a clear winner.

 

Going to let it run overnight, for whatever that's worth... and look into lower source voltage input.  

 

Which reminds me: I did do some quick measurements out of Gungnir... Most of the time I saw less than 800 mV RMS, loud passages got up to 1.2 V RMS for short periods(100ms windows).  

 

Happy Labor Day...

 

-michael

Some time ago I had mentioned to Jan an interest in trying out the HE-6 headphones with the Millenia. I emailed him the specs on them, and he said - if I understood him correctly at the time - that as long as I was coming out of the Millenia in a balanced configuration, I shouldn't need any resistors. Looks like you have proven him correct. (I never did demo the HE-6s, though). 

 

Those are some mighty fine amps you are comparing the Millenia to. So far, you findings resonate with people on the Audiocircle website: didn't appear anyone was ready to ditch their significantly more expensive amps such as the Pass designs for the Millenia, but the MG3 compared more favorably than one might have anticipated from a little $500 amp. I think Gary is correct when in a previous post he said that what makes the Millenia particularly attractive is that it sells at what could be considered a 'sweet' spot price-wise, for people on a budget looking for outstanding sound. 

post #928 of 2754

Michael:

 

Your results are really interesting.  First, I also think break-in is a mystery, but, hey, FR curves don't lie.  Or if they do, they do it very convincingly. 

 

Second, the fact that the Millenia can compete at all with the First Watt (5X the price) is pretty amazing.  Similar to what I found with the Odyssey equipment:  the TBI amp is not the best on the entire market, but it offers a great value... in addition to hours of entertainment trying to figure out battery combinations (I'm not even a battery addict, and probably won't even buy another battery because I like the sound well enough with the provided power supply... but I find myself searching the web anyway... I'm a SEARCHAHOLIC!)  ARGGGHHH!!!

 

Third, everything is relative:  The F1 sounds less bright to you than the MG3, but is there a way to know which one is "right"?  I find that to be one of the great conundrums of audio -- figuring out which pieces of hardware, or more accurately, which combinations of hardware, are actually representing the original sound produced by the musicians.  We each hear things differently, and we record/remember "reality" differently.  So which representation we think is "best" has to do with how well the equipment chain reproduces what we remember to be "right".  The high-freq bump you hear with the Millenia might represent the amp's performance... or it could be the source... or the headphones.. or it could represent the way the musicians and the sound engineers actually recorded the songs (they might have high-freq hearing loss themselves... or just really like high-freq, or boosted the high-frequencies assuming that most people are going to be listening through ear buds...).  I absolutely believe that the high-freq bump is there with your chain... but has your testing isolated it to the amp, as opposed to the source or cans? i.e., are you running freq sweeps of the amp in isolation?  If so, and you have the curves plotted, I would love to see the side-by-side with your other amps (I'm a GRAPHAHOLIC!  ARRGGGHHH!!!)

 

To my brain, in combination with the Emotiva XDA-1 and the LCD-3s, there was no high-frequency bump with the Millenia.  Which could mean the DAC and cans didn't reproduce it.  Or my hearing in the upper freqs isn't as good as yours -- though I know I am particularly sensitive to (i.e., don't like) too much high-end energy (bye-bye T1s).  I don't have testing equipment other than my brain, but I can say that while my brain thinks that the Cyclops provides more "realism" than the TBI amp when used in the same chain, the Millenia was significantly more "real" than the other amps I compared it to.  In the end, I considered the little guy good enough, cheap enough, and flexible enough in its portability, etc. that I decided to keep it, but I expect others' experiences to vary, and all I can ever recommend to folks is try it, you might like it, and it's pretty small, so if you don't like it, return shipping will be cheap (at least from CONUS). 

post #929 of 2754

My daughter, who is very familiar with live music and has the great ear of a practiced soprano, but knows next to nothing of audio gear nor any specifics of what I'm doing in the dining room, came downstairs this morning to the sound of George Winston's Autumn (piano solos), and exclaimed, "That sounds like live piano coming from the front of the house."  

 

I told her it was my new TBI Millenia MG3 amplifier and she said, "It sounds so perfectly real."   

 

I had decided that on my own, but it was nice ambushing my daughter's experienced ear with the MG3 > SM45, that way.  (I can't remember the last time I heard a live piano, myself.)

 

She's in this picture of the John Brown University Cathedral Choir. 

 

 

(You'll have to guess which one.  I'd say, the prettiest, of course!)

 

Mike

post #930 of 2754

Cool! It's always nice to get good feedback from young virgin ears that are experienced with real musical instruments. They can certainly hear much better than some of us older folks. Nature of the beast i suppose.

Quote:
Originally Posted by zilch0md View Post

My daughter, who is very familiar with live music and has the great ear of a practiced soprano, but knows next to nothing of audio gear nor any specifics of what I'm doing in the dining room, came downstairs this morning to the sound of George Winston's Autumn (piano solos), and exclaimed, "That sounds like live piano coming from the front of the house."  

 

I told her it was my new TBI Millenia MG3 amplifier and she said, "It sounds so perfectly real."   

 

I had decided that on my own, but it was nice ambushing my daughter's experienced ear with the MG3 > SM45, that way.  (I can't remember the last time I heard a live piano, myself.)

 

She's in this picture of the John Brown University Cathedral Choir. 

 

 

(You'll have to guess which one.  I'd say, the prettiest, of course!)

 

Mike

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