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Speaker amps for headphones - Page 55

post #811 of 2665
Quote:
Originally Posted by SMG52 View Post

Couldn't agree more.

 

Also, when I first got the Millenia amp, and had initial issues getting it to work with my headphones, I sincerely believe that Jan bent over backwards - not JUST to make a sale and because of his desire to please - but for me to experience  how great his little amp sounded. He is one of those guys who one really wishes to do well. But, with all my emails, etc., over the last year or so, I do hope at times he doesn't get burnt out!  He appears to run a very small business.....he's always been the one to pick up the phone, and even responds to emails over the weekends......confused_face.gif

Sounds like he found a business that also channels his passion to me :)

post #812 of 2665
Quote:
Originally Posted by brunk View Post

Sounds like he found a business that also channels his passion to me :)

 

No doubt about it.  Jan loves both music and electronics.  He is in the right line of work, which is good, because he's been doing it for a very long time...  Note that after talking to him, I know that the Millenia (in fact all of his products, but certainly the Millenia) reflects his personal preferences for sound.  So all of us who like the amp really like his musical tastes.

 

All of which makes me wonder who, if anybody, is making the "voicing" decisions at some of these other hardware companies.  Do they ever actually listen to their products?

post #813 of 2665
Quote:
Originally Posted by Gary in MD View Post

 

No doubt about it.  Jan loves both music and electronics.  He is in the right line of work, which is good, because he's been doing it for a very long time...  Note that after talking to him, I know that the Millenia (in fact all of his products, but certainly the Millenia) reflects his personal preferences for sound.  So all of us who like the amp really like his musical tastes.

 

All of which makes me wonder who, if anybody, is making the "voicing" decisions at some of these other hardware companies.  Do they ever actually listen to their products?

 

They do, just with different hardware than yours tongue_smile.gif

 

Some stuffs are even "tuned" toward certain other components/certain sonic flavors.


Edited by khaine1711 - 8/23/13 at 7:30am
post #814 of 2665

I've made some MG3 observations regarding a relationship between power supply voltage, input signal voltage and hiss.

 

1) With a 24V power supply (using either my 6-cell LiPo battery pack or the MG-3's AC adapter), I can hear hiss coming from the MG3 into my my fairly efficient, 8-Ohm Definitive Technology SM45 monitors - whether the MG3 volume control is turned all the way up or all the way down makes no difference - the volume of the hiss is constant and can be extinguished only by turning the MG3 off.  And it doesn't matter whether a source is connected or not.  The good news is that it is feint, though easily detected with my head about two feet from the SM45 drivers.  Again, this is with efficient 8-Ohm speakers and a 24V power supply via the MG3's power jack.  

 

2) With eight AA batteries in the MG3's battery compartmentsupplying ~12V instead of 24V, whether AA Energizer e2 Lithiums -or- standard AA Energizer alkalines -or- rechargeable Eneloop NiMh AAs (at 1.4V each after conditioning on a Maha MH-C9000 intelligent charger), I cannot hear any hiss coming from the MG3 into my 8-Ohm speakers, even with my ear pressed against the grille.  I get the same results, no hiss at all, when using a 12.6V 3-cell LiPo battery via the external DC power jack.  It's dead silent with a 12V supply, whether from the battery compartment or from the external power jack.  This rules out any suspicion of the 4A fuse being a source of noise (with battery compartment not being fused but with no hiss being heard when supplying 12V from an external supply that must go through the 4A fuse.)  

 

3) Here's the dilemma:  With the exception of the low-level hiss heard with a 24V power supply, even with 8-Ohm speakers (not 50-Ohm LCD-2, which has a LOT more hiss in the absence of an impedance matching box), the MG3 sounds much better at 24V than at 12V - faster, tighter control of the bass and mids, and more transparent treble.  On 12V, the MG3 is still amazing, but in comparison to what it can do on 24V, I prefer the greater detail and crispness of 24V - and remember, I'm using speakers that are more analytical and higher-resolving than my LCD-2.  So, the warmth and "muddiness" (too harsh a word, but it's in that direction) of the MG3 on 12V is even less appealing with my already warm and "muddy" LCD-2 (and I suspect this will be the case even when I've eliminated the hiss with an impedance match.)   So, hands down, 24V operation wins vs. 12V, in my book, but I strongly suspect that one could dial in an ideal ratio voltage, somewhere between 12V and 24V - where for any given efficiency of transducer (speaker or headphone) you can achieve a better balance of quite noise floor (no hiss) vs. the tighter control and transparency offered at a higher voltage.   It makes me want to get an adjustable-voltage power supply for desktop use of the MG3!   I'm thinking the "sweet spot" for my 8-Ohm Definitive Technology SM45 monitors is somewhere closer to 18V, than 12V or 24V.  I could try testing a 4-cell LiPo pack (16.8V), but I don't have one (Update: How could I forget that I alternate two of these 4-cell 16.8V LiPo packs with my Stepdance "walk-about" rig?  I will test them soon.) and would rather spend that money on the adjustable power supply. Update:  Internal battery compartment voltages between 12V and 24V could also be tested using various combinations of dummy batteries with 4.2V AA "14500" Li-Ion batteries, as previously discussed. 4x 4.2V Li-Ion AA + 5x dummy AA = 16.8V.  5x 4.2V Li-Ion AA + 3x dummy AA =  21.0V.  Both combinations fall between 12V (no hiss but inferior SQ) and 24V (tolerable hiss but superior SQ).  But I'm not likely to seek a battery compartment solution for desktop use of the MG3 with 8-Ohm speakers.  It's just something to keep in mind (playing with voltages) once I get the impedance match for use with LCD-3.

 

4)  I'll add more later, regarding the huge impact I've discovered can be made by using different DACs, just due to differences in their output signal strength. In short:  2V rms or more is good.  Less is not so good.  Stay tuned...

 

Mike


Edited by zilch0md - 8/23/13 at 9:12am
post #815 of 2665
Quote:
Originally Posted by zilch0md View Post

I've made some MG3 observations regarding a relationship between power supply voltage, input signal voltage and hiss.

 

1) With a 24V power supply (using either my 6-cell LiPo battery pack or the MG-3's AC adapter), I can hear hiss coming from the MG3 into my my fairly efficient, 8-Ohm Definitive Technology SM45 monitors - whether the MG3 volume control is turned all the way up or all the way down makes no difference - the volume of the hiss is constant and can be extinguished only by turning the MG3 off.  And it doesn't matter whether a source is connected or not.  The good news is that it is feint, though easily detected with my head about two feet from the SM45 drivers.  Again, this is with efficient 8-Ohm speakers and a 24V power supply via the MG3's power jack.  

 

2) With eight AA batteries in the MG3's battery compartmentsupplying ~12V instead of 24V, whether AA Energizer e2 Lithiums -or- standard AA Energizer alkalines -or- rechargeable Eneloop NiMh AAs (at 1.4V each after conditioning on a Maha MH-C9000 intelligent charger), I cannot hear any hiss coming from the MG3 into my 8-Ohm speakers, even with my ear pressed against the grille.  I get the same results, no hiss at all, when using a 12.6V 3-cell LiPo battery via the external DC power jack.  It's dead silent with a 12V supply, whether from the battery compartment or from the external power jack.  This rules out any suspicion of the 4A fuse being a source of noise (with battery compartment not being fused but with no hiss being heard when supplying 12V from an external supply that must go through the 4A fuse.)  

 

3) Here's the dilemma:  With the exception of the low-level hiss heard with a 24V power supply, even with 8-Ohm speakers (not 50-Ohm LCD-2, which has a LOT more hiss in the absence of an impedance matching box), the MG3 sounds much better at 24V than at 12V - faster, tighter control of the bass and mids, and more transparent treble.  On 12V, the MG3 is still amazing, but in comparison to what it can do on 24V, I prefer the greater detail and crispness - and remember, I'm using speakers that are more analytical and higher-resolving than my LCD-2.  So, the warmth and "muddiness" (too harsh a word, but it's in that direction) of the MG3 on 12V is even less appealing with my already warm and "muddy" LCD-2 (and I suspect this will be the case even when I've eliminated the hiss with an impedance match.)   So, hands down, 24V operation wins, in my book, but I strongly suspect that one could dial in an ideal ratio voltage, somewhere between 12V and 24V - where for any given efficiency of transducer (speaker or headphone) you can achieve a better balance of quite noise floor (no hiss) vs. the tighter control and transparency offered at a higher voltage.   It makes me want to get an adjustable-voltage power supply for desktop use of the MG3!   I'm thinking the "sweet spot" for my 8-Ohm Definitive Technology SM45 monitors is somewhere closer to 18V, than 12V or 24V.  I could try testing a 4-cell LiPo pack (16.8V), but I don't have one and would rather spend that money on the adjustable power supply. 

 

4)  I'll add more later, regarding the huge impact I've discovered can be made by using different DACs, just due to differences in their output signal strength. In short:  2V rms or more is good.  Less is not so good.  Stay tuned...

 

Mike

Interesting observations. Can't say I've ever noticed any background hiss on the speakers I use with the Millenia (the Clue), which are roughly 8 ohm, but around 87db efficiency. I don't remember putting my ear right up against the speaker, but I haven't heard anything from up close. Maybe I'll check that out, just for giggles. I do use ac. I wonder if Jan would be interested to hear about your observations.

post #816 of 2665
Quote:
Originally Posted by SMG52 View Post

Interesting observations. Can't say I've ever noticed any background hiss on the speakers I use with the Millenia (the Clue), which are roughly 8 ohm, but around 87db efficiency. I don't remember putting my ear right up against the speaker, but I haven't heard anything from up close. Maybe I'll check that out, just for giggles. I do use ac. I wonder if Jan would be interested to hear about your observations.

 

Just a summary of my longer post, above, with my 8-Ohm speakers, I don't have to put my ear any closer than about two feet to hear the hiss when the MG3 is on 24V power, but I can't hear any hiss at all on 12V power, externally or internally supplied, even with my ear pressed against the speaker grill.

post #817 of 2665

I've made some updates to my previous post regarding power supply voltage influence on the MG3's hiss and on SQ during playback (as heard with my 8-Ohm speakers).

 

Updates applied to my previous post... (Click to show)

 

Quote:
Originally Posted by zilch0md View Post

I've made some MG3 observations regarding a relationship between power supply voltage, input signal voltage and hiss.

 

1) With a 24V power supply (using either my 6-cell LiPo battery pack or the MG-3's AC adapter), I can hear hiss coming from the MG3 into my my fairly efficient, 8-Ohm Definitive Technology SM45 monitors - whether the MG3 volume control is turned all the way up or all the way down makes no difference - the volume of the hiss is constant and can be extinguished only by turning the MG3 off.  And it doesn't matter whether a source is connected or not.  The good news is that it is feint, though easily detected with my head about two feet from the SM45 drivers.  Again, this is with efficient 8-Ohm speakers and a 24V power supply via the MG3's power jack.  

 

2) With eight AA batteries in the MG3's battery compartmentsupplying ~12V instead of 24V, whether AA Energizer e2 Lithiums -or- standard AA Energizer alkalines -or- rechargeable Eneloop NiMh AAs (at 1.4V each after conditioning on a Maha MH-C9000 intelligent charger), I cannot hear any hiss coming from the MG3 into my 8-Ohm speakers, even with my ear pressed against the grille.  I get the same results, no hiss at all, when using a 12.6V 3-cell LiPo battery via the external DC power jack.  It's dead silent with a 12V supply, whether from the battery compartment or from the external power jack.  This rules out any suspicion of the 4A fuse being a source of noise (with battery compartment not being fused but with no hiss being heard when supplying 12V from an external supply that must go through the 4A fuse.)  

 

3) Here's the dilemma:  With the exception of the low-level hiss heard with a 24V power supply, even with 8-Ohm speakers (not 50-Ohm LCD-2, which has a LOT more hiss in the absence of an impedance matching box), the MG3 sounds much better at 24V than at 12V - faster, tighter control of the bass and mids, and more transparent treble.  On 12V, the MG3 is still amazing, but in comparison to what it can do on 24V, I prefer the greater detail and crispness of 24V - and remember, I'm using speakers that are more analytical and higher-resolving than my LCD-2.  So, the warmth and "muddiness" (too harsh a word, but it's in that direction) of the MG3 on 12V is even less appealing with my already warm and "muddy" LCD-2 (and I suspect this will be the case even when I've eliminated the hiss with an impedance match.)   So, hands down, 24V operation wins vs. 12V, in my book, but I strongly suspect that one could dial in an ideal ratio voltage, somewhere between 12V and 24V - where for any given efficiency of transducer (speaker or headphone) you can achieve a better balance of quite noise floor (no hiss) vs. the tighter control and transparency offered at a higher voltage.   It makes me want to get an adjustable-voltage power supply for desktop use of the MG3!   I'm thinking the "sweet spot" for my 8-Ohm Definitive Technology SM45 monitors is somewhere closer to 18V, than 12V or 24V.  I could try testing a 4-cell LiPo pack (16.8V), but I don't have one (Update: How could I forget that I alternate two of these 4-cell 16.8V LiPo packs with my Stepdance "walk-about" rig?  I will test them soon.) and would rather spend that money on the adjustable power supply. Update:  Internal battery compartment voltages between 12V and 24V could also be tested using various combinations of dummy batteries with 4.2V AA "14500" Li-Ion batteries, as previously discussed. 4x 4.2V Li-Ion AA + 5x dummy AA = 16.8V.  5x 4.2V Li-Ion AA + 3x dummy AA =  21.0V.  Both combinations fall between 12V (no hiss but inferior SQ) and 24V (tolerable hiss but superior SQ).  But I'm not likely to seek a battery compartment solution for desktop use of the MG3 with 8-Ohm speakers.  It's just something to keep in mind (playing with voltages) once I get the impedance match for use with LCD-3.

 

4)  I'll add more later, regarding the huge impact I've discovered can be made by using different DACs, just due to differences in their output signal strength. In short:  2V rms or more is good.  Less is not so good.  Stay tuned...

 

Mike

 

Mike


Edited by zilch0md - 8/23/13 at 9:18am
post #818 of 2665

Continued from my previous post...

 

 
4)  The input signal voltage (coming from a DAC) can have a dramatic impact on SQ with the MG3.  When I use my DACmini CX, which has a 2V rms Line Out, the MG3 is at its best, in terms of dynamics, control, detail, and transparency (using 8-Ohm speakers with a 24V power supply (AC adapter or battery).  But if I use my Sony PCM-M10 Linear PCM Recorder, with its 1V rms Line Out, the MG3 is still pretty impressive, but queing the same tracks, back to back, I can hear a difference.  The MG3 becomes less assertive, more laid-back, and transparency begins to suffer - but I'd say it's still 90% as good as with a 2V rms input signal - and I do have to turn up the volume on the MG3 to achieve the same SPL at the speakers as had with a 2V rms input - so I'm getting less headroom - the very reason it doesn't sound as good.  
 
My Sanza Clip+, which isn't truly a Line Out, but rather a headphone out, at maximum volume, these have been measured to produce only 55mV rms (about one half one twentieth the voltage of my Sony PCM-M10).  When I use the Sanza Clip+ with its volume turned all the way up, the MG3 sounds lifeless - it loses a lot of its assertiveness and dynamics, and the transparency falls apart too - sounding quite veiled, as if vocalists are singing in their sleep, under a blanket.  
 
In the owner's manual Steve Deckart (of Decware) wrote for his Decware ZSTAGE (triode tube gain stage), he writes that if you insert his ZSTAGE between a DAC and an amp, then use the gain control on the ZSTAGE to decrease the input gain to the amp (to something less than what's coming from your DAC) while simulataneously increasing the amp's volume control to maintain the same SPL at your speakers or headphones, you can reduce the dynamics and fullness of sound for a given DAC/amp combination.  Conversely, he writes that you can use the ZSTAGE gain control to increase the the input gain to the amp (to something more than what's coming from your DAC (up to about a 5dB gain, depending on the type of tube you are using), while simultanously decreasing the amp's volume control, again to maintain a constant SPL at your speakers or headpones - for the purpose of increasing dynamics and fullness of sound for a given DAC/amp combination.
 
I know I've touched on this subject before, but in an e-mail discussion I had with Jan Meier (Meier-Audio), he said (paraphrasing here) that reducing or increasing the input level to the amp with the purpose of tailoring the dynamics or fullness only works with "some amps."  Indeed, I've found that this doesn't work at all with the Emotiva a-100 Mini-x - it couldn't care less what input voltage you hit it with.  Once you turn up the volume to compensate a weaker input signal, it pretty much sounds the same.  Now that might not be the case if it were having to operate at the limits of its power capacity - with inneficient speakers, for example, that require every bit of the Emotiva's rated power, but it's certainly the case when using headphones.  
 
Not so with the MG3 (into speakers).  Even with 24V power, where it's rated at 32Watts into 8-Ohms, I'm finding that, at least with my 8-Ohm speakers, the MG3 is very sensitive to the input signal voltage.  It's not nearly as happy with the 55mV rms signal of a Sanza Clip+ as it is with the 1V rms signal of my Sony PCM-M10 or the 2V rms signal of my DACmini CX.   
 

So... If you want to use the MG3 with inefficient headphones (i.e. HE-6) or actual speakers, keep this in mind when considering DACs like the Reconessence Concero, which uses an ESS9023 chip with no gain in its downstream analog section - the Concero puts out only 1V RMS.   This rules out lots of other ESS9023 DACs, too - like the Objective DAC, the Audioquest Dragonfly, and the diminuitive Stoner Acoustics UD100.  A DAC like the (much more expensive) Wyred4Sound DAC2 would be fun to play with on an MG3, as it offers several choices of output level, but any DAC that puts out 2V rms would be fine, in my opinion, for speakers or inefficient headphones.  The MG3 is not at all like the Emotiva a-100 mini-X or even the 1.28W into 50-Ohm Burson Soloist, in this regard.  The MG3 wants to see  2V rms (when driving speakers).   Please remember that all of my observations at this point are with 8-Ohm speakers that are not as efficient as heapdhones, so it could be that the MG3 has plenty of headroom (and thus less vulnerability to lesser input voltages) with headphones.  I just haven't test that yet (waiting for the impedance match).

 

Mike 

 

Update:  Desipite the qualification spelled out in my last sentence, above, I've now emphasized that the observations I've made were with speakers, not with more efficient headphones.


Edited by zilch0md - 8/23/13 at 11:44am
post #819 of 2665

That's the effect of input sensitivity.

 

The Emotiva is very sensitive (600mV) so even a portable source can bring it to full power.

 

Base on your observation, the Millenia must have a lower sensitivity - which is quite understandable since it was designed for speaker in mind.

post #820 of 2665

It sounds like when you're running off 24v, you're putting the amp at its upper limitations. I would wager like you said Zilch that it would diminish with 18v, or only be perceptible with your ear on the driver. One more thing, maybe there's a tad too much gain in the amp when running 24v, maybe Jan can accommodate for this, or even ourselves with instructions from Jan?

popcorn.gif

post #821 of 2665
Quote:
Originally Posted by khaine1711 View Post

 

They do, just with different hardware than yours tongue_smile.gif

 

Some stuffs are even "tuned" toward certain other components/certain sonic flavors.


Yeah, sorry, I shouldn't have been as facetious as I was (I should know better... facetious never translates well on message boards).  I know they are using various types of equipment and tuning their amps based on their target market.  But it is interesting to see how their decisions come out.  The MJ seems to have been aimed in no small part at the LCDs, but to my ears (and I can only speak for my ears... they can't speak for themselves) Schiit missed the mark (no giggling), making the sound too lean, apparently to try to compensate for what some think is the LCDs' excessive mid-range (not to my ears, particularly with a good amp... but whatever). 

 

I also admit that it is very difficult to find a sweet spot in the amp business, particularly in the mid-priced and above audio hobbyist market, because transducers (both speakers and HP) all sound so different from each other:  what works for the LCD's is not likely to work with the HD600s or HD800s.  Also, the signal the amps are being sent from further up the chain also differs, not as much as transducers, but still enough to change the signal audibly.  And then there is the problem that every individual hears things differently, so that no matter what signal the headphone transducer ultimately ends up transmitting, the processors receiving the signal (our brains, such as they are) are translating that signal uniquely, so the designer is forced to use somebody (or several somebodies) as the model(s), and that person(s) may, or may not, represent the actual target audience. 

 

In the end, I guess it comes down to whether any particular customer/enough customers using their own sources and transducers process a given signal the same way that the hifi amp designer (or their designated model listeners) does.  If so, then enough customers will like the sound and the amp designer makes a living.  If not... then they won't... 

 

Jan Plummer and Klause Bunge (Odyssey) apparently hear things pretty much the way I do.  The guys at Schiit not so much.  But I believe they are all making a living, so apparently the market is broad enough to support all of them.

 

Final note... none of these musings have anything to do with mass market audio.  Being an audiophile snob, I am convinced that the vast majority of people (including many I know and love) are tone deaf, or just incapable of comprehending the joy of well-reproduced sound.  These sorts of folks were happy with transistor radios in the sixties, 8-track tape players in the 70s, boomboxes in the 80s... and flat-screen speakers and Beats today.  They offer no challenge to an amp designer, in that as long as the amp will provide sound from a transducer at ample volume (ample = loud enough if desired to do permanent damage to eardrums), folks in the mass market will be happy, or at least willing to buy the product.  I wish I could be one of those people... then I would have lots of money to spend on things like... oh, I don't know, what do normal people spend their money on? 

post #822 of 2665
Quote:
Originally Posted by Gary in MD View Post

[snip]  

 

I wish I could be one of those people... then I would have lots of money to spend on things like... oh, I don't know, what do normal people spend their money on? 

 

Really loud home theater setups.  That's what some of my neighbors are into. Loud bass especially. If it shakes the walls, they're happy. Play the Top Gun DVD for demos.   :-)

post #823 of 2665

The reality is that loud is relatively cheap... good is expensive... If only it were the other way around...

post #824 of 2665
Okay, so I'm home now; I turned on the Millenia hooked to my speaker system. Just to mention, I am using an Oppo BDP 105 fed directly into the Millenia. I turn the volume of the amp full on, and then use the volume control on the Oppo to control sound. If I put my ear literally up against the tweeter, I can hear a slight whooooosh sound. But I can't hardly hear anything if my ear is just inches away. So, I have to say, it's pretty silent. I have read on the Audiocircle blog that some people with 'dirty' ac preferred using batteries with the Millenia, but I don't recall anyone with hiss issues....and of course this was over speaker systems, and pretty efficient ones too. So, I am at a loss to know why one would be getting such audible hiss, from several feet away, over speakers. Grounding issue?
post #825 of 2665

I'm running the Millenia, AC in, fed by the Emotiva XDA-1 (1V RMS nominal out, 12V peak) with TBI Diamond 1 speakers right now with no music playing. At 9 on the dial, no hiss, but at about 11, you can hear it if you put your ear to the speakers.  Of course you can also hear the computer wheezing away right below the shelf the speakers are on.

 

However, feeding in music at 11 o'clock on the dial, the speakers are playing so loud the computer cabinet I have them in is resonating and distorting the sound to the point that I can't listen to it.  At normal listening levels, a bit under 9, everything is fine, and the hiss is inaudible. 

 

Dunno what all this means for normal listening, but I figured I'd report anyway...

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