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Speaker amps for headphones - Page 58

post #856 of 2961
Quote:
Originally Posted by zilch0md View Post

Hey Stew,

 

For sure!  What you're looking for is "a linear regulated DC power supply" rated at your voltage of choice with at least a 3-Amp current capacity (higher is better because you can't always trust the ratings) - with heat sinks - no fans (thanks Gary!)   

 

I can't say that 15V is going to be the sweet spot for my headphones once I try them with the forthcoming impedance match, but 15V sure great with my speakers.  I don't know how you would go about discerning which voltage gives you the sound you want with your transducers of choice, without having a way to power the MG3 at different voltages (in the range 10V to 26V, per the Texas Instruments datasheet).  

 

But once you do figure out which voltage you want, here are some examples of fixed-output linear regulated DC power supplies having at least a 3Amp capacity:

 

13.8V  6A  http://www.amazon.com/Pyramid-PS8KX-Amp-Power-Supply/dp/B000A896GG

 

Get one of these, too:

 

http://www.amazon.com/2-1mm-5-5mm-11-2mm-Plug-Cord/dp/B0002KRCRW

 

Unfortunately, it's hard to these in fixed voltages other than 12V (or 13.8V).

 

You might try a switch-mode regulated power supply (as opposed to linear regulated power supply), but switch-mode power supplies can induce noise. The only way to know for sure is to test it and see if you can hear any noise in the signal.  Amazon allows returns.......

 

Here are examples you might want to try (they've got the correct sized plug, plenty of amps, ready to go):

 

15V 5A  http://www.amazon.com/Power-Supply-2-5mm-Regulated-Adapter/dp/B006QZUSPA

 

18V 4A  http://www.amazon.com/Power-Adapter-2-1mm-Regulated-Supply/dp/B006QZZ00I

 

 

If you just bought these last two (and hope that they aren't noisy), you'd be able to compare them to 12V internal AA's and the 24V power supply that came with the MG3.  

 

12, 15, 18, and 24 would be a nice spread to test.  Send back anything you don't want to keep.

 

:-)

 

Mike

Or, we could sit back and let the guys on that Audiocircle thread I linked to above figure it all out. They are in pursuit of the best linear regulated power supply. wink.gif

post #857 of 2961

Potter:

 

I think the 6.3mm is the outer diameter of the barrel, not the length.  It could be 5.5mm in length...  But as I've said, I'm not exactly an expert in these things.  Here's a picture of the diagram so all of you Egyptologists can debate the meaning:

 

 

 

Just let me know if it means the world is coming to an end soon, I've got things I'd want to do then...

post #858 of 2961
Quote:
Originally Posted by potterma View Post

Any chance that's a misprint on the silkscreen on the back of the MG3?  I'm not sure the power jack would even make contact with a 5.5mm barrel in a 6.5mm jack...  Somethings not adding up here....

 

 

 

 

 

 

Go figure!   But it works fine.

 

 

http://www.powerbox.info/products/pdf/LTE60E.pdf  <-- This datasheet shows it comes with a "choice of output connectors."   biggrin.gif

 

Mike


Edited by zilch0md - 8/25/13 at 10:16am
post #859 of 2961
Quote:
Originally Posted by Gary in MD View Post

Potter:

 

I think the 6.3mm is the outer diameter of the barrel, not the length.  It could be 5.5mm in length...  But as I've said, I'm not exactly an expert in these things.  Here's a picture of the diagram so all of you Egyptologists can debate the meaning:

 

 

 

Just let me know if it means the world is coming to an end soon, I've got things I'd want to do then...

5.5 mm (or 6.5 mm or 6.3 mm depending on which diagram/measurement you use as a reference) is the outside diameter of the barrel.  The second dimension is the OD of the inner pin (2.1 mm or 2.5 mm).  Length is usually specified separately and usually only in the data sheet.  9.5 mm and 12 mm barrel lengths are the two common standard lengths.  Inner pin length varies all over the place.

 

Its interesting that the silk screen on the back of your amp says 6.3 mm, but the photo on TBI's website says 6.5 mm.  Especially curious is the fact that the power supply supplied by Jan has a barrel OD of 5.5 mm.  Clearly a mismatch.  

I just went through a little exercise at work specifying a DC power connector for a Li Ion battery powered instrument and learned more than I ever wanted to know about DC power jacks and their mating plugs.  

 

Thanks for the assist, Gary.  Not the end of the world... :)  Just trying to figure it out... If I was more patient, I'd just wait for my amp to arrive and take some measurements!

post #860 of 2961

Thanks, Mike!

post #861 of 2961
Quote:
Originally Posted by zilch0md View Post

[snip]

 

 

http://www.powerbox.info/products/pdf/LTE60E.pdf  <-- This datasheet shows it comes with a "choice of output connectors."   biggrin.gif

 

Mike

 

I noticed at the top of the datasheet for the MG3's L.T.E. (brand) power adapter (model LTE60E-S4-1), that it's part of a line of adpaters known as the "Switchbox LTE60E Series".

 

As is normally the case with PSUs of this shape, it seems that this PSU is a switch-mode power supply, meaning that it's regulated, but it's not a linear PSU - and thus, it has the potential to inject audible noise, but I don't here anything unpalatable when using it with the MG3.    The CEntrance DACmini CX uses a similar switch-mode power supply, by the way.

 

Anyway, if the MG3 has filtering to deal with switch-mode noise, then other voltages from similar switch-mode PSUs should be "OK".  Ultimately, I would prefer to use a linear regulated PSU, just on the knowledge that they are quieter.

 

Mike

post #862 of 2961

For those with the Topping TP-60 - anyone measure the output impedance? And I noticed they were using it with the HE-500..was there any hiss at normal volumes? I may have to chase this and the TBI Millenia at one stage and see how they fare against the DACmini. This all seems great fun (albeit slightly costly).

post #863 of 2961

Following up on my previous post regarding the MG3's AC PSU...

Quote:
Originally Posted by zilch0md View Post

I noticed at the top of the datasheet for the MG3's L.T.E. (brand) power adapter (model LTE60E-S4-1), that it's part of a line of adpaters known as the "Switchbox LTE60E Series".

 

As is normally the case with PSUs of this shape, it seems that this PSU is a switch-mode power supply, meaning that it's regulated, but it's not a linear PSU - and thus, it has the potential to inject audible noise, but I don't here anything unpalatable when using it with the MG3.    The CEntrance DACmini CX uses a similar switch-mode power supply, by the way.

 

Anyway, if the MG3 has filtering to deal with switch-mode noise, then other voltages from similar switch-mode PSUs should be "OK".  Ultimately, I would prefer to use a linear regulated PSU, just on the knowledge that they are quieter.

 

Mike

 

Researching the AudioCircle.com thread that Stew has referenced a couple of times (thanks Stew!), Jan Plummer has indeed put considerable effort into tweaking the power circuitry within the MG3 to improve its sound when used with the 24V switch mode PSU:

 

Quoting Jan Plummer by way of a post by OzarkTom at Audiocircle.com:

 

My curiosity got the best of me early in the week. I decided to write the company on how on earth did they get the AC sound better than the battery. I always found the battery to be better. This is what Jan Plummer wrote me.
 
"This is a better quality switching supply than most so I was able to flatten the ESR with those film caps over the full audio range. I went through quite an array of potential types of bypass caps that would work in conjunction with the stable low frequency regulation of the wall wart. The amp now has electrolytic, ceramic and film bypass caps. The AC supply is extremely well regulated for low frequency response. The voltage does not change however it loses its integrity above 100 Hz. Capacitors have a sound as batteries and these films are the most neutral I have found and the only ones of proper dimensions for this value. The two capacitors in parallel are better for ESR profile than a single large one.
 
This combination of the special film caps and damping resistor creates a linear non peaked ESR response from the AC supply that remains in place.The fact that we have only one voltage creates an inherent equality for both channels when applying this upgrade. Channel seperation is also greatly improved providing enhanced soundstaging and depth.
 
The battery is fairly well regulated for low frequencies (depends on AH) however its high frequency response is relatively poor and not constant with frequency. Different batteries will sound different. The battery also receives a benefit in high frequency control but again the batteries contribution to ESR varies with discharge and battery type."

 

Mike


Edited by zilch0md - 8/27/13 at 5:30am
post #864 of 2961

I realize this is a headphone site, but just gotta say that this past weekend I was listening over my speaker system to a cd I just purchased - Laurence Juber plays The Beatles, Volume 2 (both volume 1 and 2 are highly recommended). I don't know if it would have been much clearer, any more real, if he were sitting in our living room. bigsmile_face.gifAnd I've heard and owned some pretty nice systems over the last 30 or more years, and I play guitar myself so I am very aware of what a guitar sounds like (own three acoustics, a resonator, an electric....) That Millenia, at $500, is simply astonishing - with compatible speakers, of course. (I wouldn't try it with a pair of Maggies.....although at lower levels, might sound pretty great too). (Speakers I own now are The Clue, by the way). I read on another thread that it does require some break in.

As I posted on a different thread, I also had a pair of Audeze LCD2s in house last week. Except for the clamping force confused_face.gif, I was really taken with those phones and the Millenia (with resistor box). The phones are on their way back to the Cable Company now, but maybe with the velour pads (they only had leather pads for demo), there is a pair in my future. Maybe. Their sound was right up my alley. 

post #865 of 2961

Thanks for the music recommendation, Stew!  

 

There are a few cover bands out there who have produced startlingly good recordings.  Mark Cohn's Listening Booth: 1970 is one that comes to mind, where the track Maybe I'm Amazed makes nearly any equipment sound better.

 

I heard the LCD-3 only this past June, at the Dallas Head-Fi meet, but I didn't like them as much as my LCD-2 (sacrilege!)   I heard them on several really nice amps, including a Cavalli Liquid Glass, a Headamp GS-X, and my own Burson Soloist - each with nice sources (including OPPO CD players, etc.  But, to my ears, the LCD-3 was almost too refined, almost boring, despite the fact that I could tell it was a superior headphone overall, hands down, for general purpose use.  I confess, it's my love of the admittedly "swollen" bass that always leaves me coming back for more with the LCD-2.  It's just a lot more fun than the LCD-3 - but not overdone in that direction - it still has finesse, unlike a lot of bass-heavy phones.  And... it's more forgiving in terms of its resolution.  If my speakers are any indication of what the MG3 will do with my LCD-2 (once I get the impedance match), I wouldn't want any more resolution (again, sacrilege!)  

 

biggrin.gif

 

Mike

 

Update:  I just ordered Laurence Juber plays The Beatles, Volume 1.  beerchug.gif


Edited by zilch0md - 8/27/13 at 4:57pm
post #866 of 2961

Wow...  I was just "shuffling" through my WAV files when this started playing - this track is made for the MG3.  I've never heard it any better.  Immersive. Engaging. Beautiful.

 

Dire Straits - Brothers in Arms - Ride Across the River

 

 

Mike

post #867 of 2961

If you want to hear what a recording really, truly sounds like, and I mean everything on the recording as it was laid down in the studio or on stage, then the LCD-3 (with updated transducers) is an incredible tool, significantly better than the LCD-2 to my ears.  With the Cyclops feeding the LCD-3s I truly believe I am hearing sound that is as close as you can get to a perfect reproduction of the original sound as is possible for a reasonable amount of money.  Perhaps a mega-buck (as in, at least six figures left of the decimal) speaker system in an acoustically perfect room could do better, but I will never have that.  Maybe an Abyss can do better, but at $5K it would have to be 2.5 times better, and I just don't know how it can be.

 

If you don't have an obsessive need for that level of reality, then the LCD-2 is a really nice headphone, and I understand exactly what Mike is talking about when he talks about its endearing flaws.  With the Millenia, the LCD-3 is slightly less perfect than it is with the Odyssey amp, but in some ways the extra warmth and small bit of color the amp provides is comforting.  Maybe that is because we are so used to hearing less-than-perfect sound from audio equipment that it sounds better to us.  Whatever the reason, it makes us feel good, and that's really the entire point of this whole activity. 

 

And Mike, when does that silly magic box show up?  We're waiting, you know...popcorn.gif

post #868 of 2961

Heee-heee!  It's been said many times by others, and by myself, but I can't help saying it again - I love the way you write.  "Endearing flaws," for example. That's perfect.  You've restated my sentiment better than I had.  As my (corny) father used to say to people who could write well, "Your'e a poet and don't know it."  

 

I intend to borrow some LCD-3 for a good long listen on my MG3, at the Dallas meet next month.  I've not written them off entirely, by any means. I think that LCD-2 fans, more so than those of many other headphones, tend to get "formed" to the LCD-2 - such that the longer you listen to them, the the more "normal" they sound at the expense of everything else sounding "abnormal." 

 

Regarding the impedance match - I paid for it within 24 hours of paying for the MG3, but Jan had said it would take about a week to build it, then just yesterday, he begged my indulgence to postpone the job for a few more days, so I obliged him, readily. I'm having SUCH a good time with my MG3 > Definitive Technology SM45, I might get "formed" to this rig before the match box gets here!  I've pretty much reached the conclusion that my LCD-2 are not going to be able to compete - no way.  I haven't listened to any headphones since the first night the MG3 got here, a week ago. I am seriously enjoying these monitors now, but they sounded horribly bright and harsh on the Emotiva Mini-X a-100 (which is now boxed up ready to sell.)

 

Oh, back to Head-Fi...  It occurred to me today, that I could omit four binding posts and four banana plugs from my signal path to the LCD-2, by asking Jan if he would allow me to send him two 14-inch lengths of my favorite speaker wire to pass through holes on the MG3 side of the match box for a soldered connection to a terminal strip inside, such that the match box will have only four binding posts on top (instead of eight) - into which only banana plugs from the headphones will go.  The speaker wire pig tails will be terminated with banana plugs that go to the MG3's binding posts.  Jan agreed to do this, no problem, with no difference in price.  So I've got 28-inches of KnuKonceptz 10-AWG 462-strand OFC speaker wire ready to Priority Mail to Jan tomorrow morning in a bubble pack.  

 

So now Jan's waiting on  me - which gives him more time to finish whatever he's into at the moment. 

 

wink.gif 

 

Back to my near-field monitors - which offer much better sound stage and imaging than any headphones I've ever heard.  That's heresy, I know, but I'm going koo-koo listening to this MG3 setup!

 

Mike


Edited by zilch0md - 8/27/13 at 10:02pm
post #869 of 2961

Wow, Jan is such a flexible and accommodating guy to work with. 

post #870 of 2961

Absolutely - and that's why I'm willing to give him all the time he wants to get the job done.  biggrin.gif

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