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Meier Audio Quickstep (also Stepdance and 2Stepdance) Discussion and Impressions Thread - Page 152

post #2266 of 2790
Joy! :-)
post #2267 of 2790

Hey guys does the Xp8000 run pretty hot while it is being charged? I must've plugged it in to charge no more the 15 minutes and it got pretty hot. Not even close to warm, the damned thing was hot!

post #2268 of 2790

Hi mine only get "hand warm" as we call it in Germany.  I do not think that "hot" is a good sign. But maybe @ first time charging it is different, let's hope so at least.

post #2269 of 2790
Quote:
Originally Posted by wormsdriver View Post

Hey guys does the Xp8000 run pretty hot while it is being charged? I must've plugged it in to charge no more the 15 minutes and it got pretty hot. Not even close to warm, the damned thing was hot!

That battery pack has to be defective if it's actually getting "hot." Lithium batteries can spontaneously burst into flame. They don't explode - that's a myth - they just burn your house down, crash passenger jets, and at the very least, spew toxic gasses and soot everywhere, leaving you wondering if you should call in a HazMat team to detox your home.

https://www.google.com/search?q=lithium+battery+fire

You should return that battery - it's defective. Bummer. (Hopefully it will make the trip without incident.)

Mike
post #2270 of 2790
So I will be the proud owner of a lightly used QuickStep, hopefully tomorrow. smile.gif

Honestly, I'm most excited to go down to the store and drive some nice headphones I can't afford well enough so that I can hear how they should actually sound.
Edited by vwinter - 6/14/13 at 4:27pm
post #2271 of 2790
Quote:
Originally Posted by zilch0md View Post


That battery pack has to be defective if it's actually getting "hot." Lithium batteries can spontaneously burst into flame. They don't explode - that's a myth - they just burn your house down, crash passenger jets, and at the very least, spew toxic gasses and soot everywhere, leaving you wondering if you should call in a HazMat team to detox your home.

https://www.google.com/search?q=lithium+battery+fire

You should return that battery - it's defective. Bummer. (Hopefully it will make the trip without incident.)

Mike

eek.gif HOLY TICKING TIME BOMB BATMAN!!!

 

Battery will be returned... I hope the USPS guy doesn't kick it around too much!evil_smiley.gif

 

 

Thanks for the eyeopener Mike, Yikes!


Edited by wormsdriver - 6/15/13 at 4:19am
post #2272 of 2790
Quote:
Originally Posted by wormsdriver View Post

eek.gif HOLY TICKING TIME BOMB BATMAN!!!

 

Battery will be returned... I hope the USPS guy doesn't kick it around too much!evil_smiley.gif

 

 

Thanks for the eyeopener Mike, wikes!

 

I guess that's why the UPS vans don't have doors - so that the drivers can jump out into oncoming traffic when a laptop battery catches fire.  tongue.gif

post #2273 of 2790
Quote:
Originally Posted by zilch0md View Post

Coincidentally, I've just received another PM requesting information on how to obtain the WI15 inline voltage regulator cable for use with the Stepdance (or QuickStep) and the Energizer XP8000 LiPo battery pack - for a regulated 15VDC, on the go.

 

So...  I have updated my original post on this subject (with new links and alternatives for the adapter that plugs into the power jack of the Stepdance):

 

http://www.head-fi.org/t/507835/meier-audio-quickstep-also-stepdance-and-2stepdance-discussion-and-impressions-thread/1155#post_7344337

 

1000

 

Mike

I suppose that going from 12v to 15v makes a big difference, as that Energizer is an expensive battery pack.

post #2274 of 2790

Hi Angular Mo,

 

Quote:
Originally Posted by Angular Mo View Post

I suppose that going from 12v to 15v makes a big difference, as that Energizer is an expensive battery pack.

 

It depends on the efficiency of your headphones or IEMs.   It is highly unlikely that anyone could hear a difference between between even 9V and 15V using IEMs that suffer no lack of headroom with a Stepdance at 9V.   But lots of people have testified in this thread that they hear big improvements when using headphones like the LCD-2 - improvements that are all consistent with an increase in Watts rms - the same as you would enjoy when increasing power output to inefficient loudspeakers in a HiFi system.

 

     Quoting an earlier post:


A   9.0-Volt battery (or PSU) will yield an   8.0% increase in Maximum Output Voltage (Vpp) to the headphones, relative to an 8.4-Volt LiPo rechargeable battery.

 

A 12.0-Volt battery (or PSU) will yield a   57.8% increase in Maximum Output Voltage (Vpp) to the headphones, relative to an 8.4-Volt LiPo rechargeable battery.

 

A 12.6-Volt battery (or PSU) will yield a   69.7% increase in Maximum Output Voltage (Vpp) to the headphones, relative to an 8.4-Volt LiPo rechargeable battery.

 

13.8-Volt battery (or PSU) will yield a   95.4% increase in Maximum Output Voltage (Vpp) to the headphones, relative to an 8.4-Volt LiPo rechargeable battery.

 

A 15.0-Volt battery (or PSU) will yield a 123.7% increase in Maximum Output Voltage (Vpp) to the headphones, relative to an 8.4-Volt LiPo rechargeable battery.

 

Basically, you're running with more Watts to the headphones when you increase the supply voltage to the Stepdance (up to the 15-Volt maximum).  You can find many explanations online of why more watts is better for any desired volume level and speaker or headphone sensitivity.

 

So... you can more than double the output voltage to your headphones (and thus, the Watts) by using a 15-Volt supply instead of an 8.4-Volt supply!

 

And a 15-Volt supply actually increases the output voltage (and Watts) by 41.8% over a 12-Volt power supply (even though the supply voltage has only increased by 25%, from 12 to 15)!  

 

A 41.8% gain in output voltage to your headphones (increasing the supply voltage from 12V to 15V) could be dramatic for a HiFiMan HE-6 that would still be suffering a lack of power with any of the Stepdance family of amps, even with a 15V supply voltage.  But that same 41.8% gain in Watts rms would be worthless when using something like the Shure SE530.

 

The thing that I fear is most misunderstood about the use of 12V or 15V battery packs or PSUs is that the Meier portable amps are not somehow dependent on these "solutions" where other portables do fine without them.   Just about any portable amp that accepts a variable supply voltage is using op-amps that create a higher output voltage (Vpp) to the headphones when given a higher supply voltage (Vs).   The  

 

Here's something else to consider when deciding between 12V and 15V:

 

Quoting an earlier post:

 

But here's a less known benefit:  When examining datasheets for op-amps, you can see that typically... 
 
THD and noise actually decrease as the supply voltage (and output voltage) increase.
 
This results in less audible distortion and a lower noise floor.  But Jan Meier's designs have ink black noise floors to begin with. (More on that topic, here.)
 
There comes a point, however, where the THD + Noise curve no longer improves with increasing supply voltage.
 
For the record, Jan Meier once posted to this thread that it's OK to use [a linear regulated power supply with] a voltage as high as 16V, despite his having labeled his power jacks with a maximum of 15V, but having more of something is not always better than having less!
 
Have a look at Figures 7 through 12 in this datasheet for the Texas Instruments OPA1611 (the Op-amp used in the Meier Audio Stepdance):   
 
Notice at the top of the page above Figure 7, it gives the temperature, voltage, and resistance used for their measurements and the following text can be found there:   Vs = ±15V     
 
That means that all of those THD+Noise charts are being presented for a situation where the Vs  (supply voltage) had a swing of ±15V.   Surely, this must be the supply voltage at which Texas Instruments has found their op-amp delivers the best performance in terms of distortion and noise.
 
Now go to the first page of the that same PDF file and look at the top left where it says "FEATURES" and you will find this text:
 
WIDE SUPPLY RANGE: ±2.25V to ±18V
 
Ask yourself, "Why did Texas Instruments present THD+Noise measurement charts taken at ±15V, when the op-amp can handle a supply voltage as high as 18V?"   Answer: The quality of the sound is best at ±15V.  
 
Going to supply voltages higher than 15V (up to 18V) increases the total Watts going to the headphones, but at the expense of best possible THD+Noise performance - not to mention other potential problems, with heat or oscillation, or ???.
 
So, just going by the OPA1611 datasheet, best possible sound quality is had at 15V.  No less, and no higher.  wink.gif

 

It thrills me just knowing that when operating with a 15V supply voltage, I'm getting the lowest possible THD + Noise, but I seriously doubt that anyone could actually discern the difference between the THD + Noise at 12V vs. 15V (or even the difference between 8.4V and 15V, for that matter).  Even with a very good DAC, the right recording, highly resolving headphones, and golden ears...  maybe.   smile.gif

 

The efficiency of your headphones is the more pressing factor, by far.  What headphones will you be using?  

 

Mike

post #2275 of 2790
Hey all, kind of new here.

I have a concern:

I read that the QuickStep is supposed to be very good with hiss but I am getting audible hiss starting around 2 o'clock on the volume knob and very audible hiss by full volume on low gain with my IEMs, both on battery and 15v adapter power.

Should I be worried?
post #2276 of 2790
Please give us more data, like which can and source you use. If the source produces hiss, any amp would just amplify that hiss.
post #2277 of 2790
I've tried it only with the iPhone 4S.

It was most noticeable with the Panasonic HJE900 an older dynamic driver IEM. 26Ohm and 100dB sensitivity, but sounds more sensitive than the specs would make you think.

I hear it too but to a lesser extent starting at almost 3 o'clock on the volume knob with the TDK BA200 which is a dual BA, at 35ohm and 121dB sensitivity, but really doesn't sound all that sensitive.

I haven't tried it with my desktop DAC yet, a Yulong D100 MKII because I am waiting on a RCA to 3.5mm cable.

My other higher quality IEMs are traveling so I won't have the opportunity to test them for a couple of weeks.
Edited by vwinter - 6/16/13 at 1:01pm
post #2278 of 2790
Quote:
Originally Posted by vwinter View Post

Hey all, kind of new here.

I have a concern:

I read that the QuickStep is supposed to be very good with hiss but I am getting audible hiss starting around 2 o'clock on the volume knob and very audible hiss by full volume on low gain with my IEMs, both on battery and 15v adapter power.

Should I be worried?

this apply to me too with the low gain and my CIEM. However, I hardly turn the volume more than 12 o'clock as the music is dangerously loud to me. At the same time, I tried high gain with my HD650, I realized that I have to turn the volume higher to have the same perceived loudness to my CIEM, but I don't hear hiss. So, at least I'm in the noise free range

post #2279 of 2790
Thread Starter 
Quote:
Originally Posted by vwinter View Post

Hey all, kind of new here.

I have a concern:

I read that the QuickStep is supposed to be very good with hiss but I am getting audible hiss starting around 2 o'clock on the volume knob and very audible hiss by full volume on low gain with my IEMs, both on battery and 15v adapter power.

Should I be worried?

 

Yes mild hiss starting around 2 pm with sensitive IEMs is right. At full volume the hiss should be fairly loud.

 

However all amps hiss at some volume. The question is whether is has audible hiss at listening volumes. Personally I listen at 11:00 or 11:30, for really loud maybe 12:30, with  most 16 ohm IEMs. Not a chance do I get close to 2 pm or hearing any hiss.


Edited by cooperpwc - 6/16/13 at 9:45pm
post #2280 of 2790
Quote:
Originally Posted by cooperpwc View Post

Yes mild hiss starting around 2 pm with sensitive IEMs is right. At full volume the hiss should be fairly loud.

However all amps hiss at some volume. The question is whether is has audible hiss at listening volumes. Personally I listen at 11:00 or 11:30, for really loud maybe 12:30, with  most 16 ohm IEMs. Not a chance do I get close to 2 pm or hearing any hiss.

Awesome. I max out by 12:30-1 depending on sensitivity and it's inaudible there. When my Heaven V gets back to me, I doubt I'll even hit 12.

And absolutely no channel imbalance is amazing. I can't wait to get some more time on it but my first impression is that it sounds incredibly refined.

I guess my D100 II doesn't even turn the amp on until it gets an active signal becuase it's dead silent even on max volume when I've plugged into the headphone jack. I have no other explanation lol.

Thanks coop! (I've been watching Twin Peaks, let me know if that isn't cool lol)
Edited by vwinter - 6/17/13 at 7:15am
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