[iFi audio]

  iFi,
 
a couple questions regarding "Power Matters" mW bumps-
 
1.  are the 10V, 5.5V, 2V numbers actually "Vrms" ?  I'm always confused by what vendors spec/report/how.
2.  I'm assuming the mW numbers are cumulative values (total output) for:  Left channel + Right channel?
(ie.  in your Normal mode 1900 mW , 16Ohm,  would deliver 950 mW to Left channel + 950mW for Right. = 1900) 
 
Lastly:
the Ohm's law math numbers "added up" in your earlier specs for the various Volts at 16ohm, 32, 64ohm, etc.
today at the new 5.5V (16 and 32 Ohms) and 2V values (8 and 16 Ohms), plugging into Ohm's law for values given the mW numbers do compute with what you reported above.
 
but for the 10V value:
at 64 Ohms, does compute (=1562 mW)
but at 16 Ohms, math says = 6250mW.  not the 4000 mW reported.
 
Can you explain my bad math or the specific power adjustments?
thank you.

 
Hi,
 
1. The Volt are Volt RMS and can be sustained indefinitely (well, until battery is empty if not on an extra high-power USB Port) into the impedance listed.
 
2. The numbers are per channel.
 
Further comments:
So 10V into 64 Ohm can be sustained with sinewave testing.
 
Limitations in terms of power supply current and heat-sinking mean if we use a much lower impedance the protection circuitry will limit available current for sinewaves.
 
We test maximum power with sinewave bursts, which simulate music with a 20dB crest factor. This is a realistic test for what is possible with for example, well-recorded classical music.
 
Under those tests into 16 Ohm (and 8 Ohm where indicated) we get the stated results into the stated load.
 
So in Turbo mode with 16 Ohm load we run out of peak current before we run out of voltage, so only 4,000mW maximum power (for musical peaks), but 10V into higher impedances.
 
We can output continuous power in Turbo mode and Normal of around 1,500mW into any load low enough to draw enough current.
 
So Turbo and Normal mode would give each 1,560mW continuous (sinewave) power into 16 Ohm, in Turbo mode we also get 1,560mW continuous into 32 Ohm and 64 Ohm, for even higher impedance we run out of voltage before we run out of current.
 
Bty, in practice the continuous sinewave figure is not useful. Music is not a continuous sinewave, but rather something like this:
 

 
If you draw a "zero" line into this, the power used by the music is the area "under the curve",meaning between zero line and the curve.
 
You can see many high and narrow spikes, but the average power is low.
 
Compare to sine:
 

 
So a steady sine wave power rating does not help to understand what will happen with music. 

 
 
Thanks

 

[jexby]

iFi,
 
as always, cheers for the great reply and clarity.
it's obvious that this battery powered aluminum tube of genius will have enough power to blow the doors off my new HE-560.
 
 
 
Note to micro iDSD followers here:
(goal towards an FAQ)
 
was any progress made in "collecting" all the OTW, specs and Engr features into a single, Google Doc?
I'm having a hard time searching/finding many of the past OTW and iFi write ups in a concise fashion.
 
such as:
does micro iDSD operate from USB power when first plugged into a USB cable (to PC), and then turning on via the volume knob?
(same as nano iDSD?)
or is some battery power still used,  etc.

 

[Garraty]

I thought this was to be a DAC? Or is it an amp and DAC combo?

 

[jexby]

  I thought this was to be a DAC? Or is it an amp and DAC combo?

 
amp and DAC combo for certain.

 

[MLGrado]

 
Another purpose for the nano is to occasionally put it back in the signal path and tell the rest of us what you find to be the differences between the two.

Indeed!

 

[Garraty]

   
amp and DAC combo for certain.

 
Ah, thanks for the clarification. So I take it the iDSD Micro is an improvement on the iFi iDAC?

 

[MLGrado]

more like an improvement on the iDSD nano...  the iDAC is an ESS based chip, PCM only.  
 
the iDSD series is designed for optimal DSD decoding, as well, using a Burr Brown chip, and custom software....
 
 
all three have headphone amps on-board...

 

[john57]

  additional 1 week wait? geez, you started this thread on 21 March...and you'll have it in retailers' hands in just FOUR months time. that's pretty awesome. i don't think anyone here will quibble about an extra week...i'm just surprised it's production ready so quickly. well done.

Yes, it is a fast development time which helps to keep costs down. IFI seems to go full stream in April. Much quicker development time than similar projects using KickStarter as an example. Very impressive.

 

[maricius]

PER CHANNEL? Those numbers are incredible

 

[roamling]

  OK,Dixter,here is a few more... If you have all these,maybe someone else could benefit...  

 
http://ifi-audio.com/audio_blog/quad-speed-dsd256-works-by-ve-kuseru-dorm-nantes-of-japan/
 
 

 
I downloaded these files yesterday but here is my question. I have JRiver 19 for Windows, it plays DSD 64 and 128 but did not seem to be able to play the DSD 256 files (right now I have to sample DSD to PCM until I have the micro iDSD but the DSD 256 files just generated an error in JRiver). Is JRiver 19 able to play these files in general and if not which software in Windows is? 

 

[RadioWonder737]

   
I downloaded these files yesterday but here is my question. I have JRiver 19 for Windows, it plays DSD 64 and 128 but did not seem to be able to play the DSD 256 files (right now I have to sample DSD to PCM until I have the micro iDSD but the DSD 256 files just generated an error in JRiver). Is JRiver 19 able to play these files in general and if not which software in Windows is? 

This is all I have for JRiver,I hope it is helpful...          http://wiki.jriver.com/index.php/DSD_Format
 
Also if you just want to do a Test,you can use AudioGate...
 
Latest Version 3 doesn't let you Export or Burn To Disc,but will play Hi-Rez files... http://www.korg.com/us/news/2014/0203/
 
I still have an older AudioGate Version 2.3.3...(with Twitter activation)that does it all...(Just never update it to new version)...

 
I am not familiar with JRiver,I use Foobar 2000... 

 

 

[roamling]

  This is all I have for JRiver,I hope it is helpful...          http://wiki.jriver.com/index.php/DSD_Format
 
Also if you just want to do a Test,you can use AudioGate...
 
Latest Version 3 doesn't let you Export or Burn To Disc,but will play Hi-Rez files... http://www.korg.com/us/news/2014/0203/
 
I still have an older AudioGate Version 2.3.3...(with Twitter activation)that does it all...(Just never update it to new version)...

 
I am not familiar with JRiver,I use Foobar 2000... 

 

 
Thanks. My point here is that I think Jriver wont play DSD 256 at all, no matter what settings are selected.

 

[iFi audio]

   
Thanks. My point here is that I think Jriver wont play DSD 256 at all, no matter what settings are selected.

 
Hi,
 
DSD256 Checklist for JRMC19:
 
1) iDSD nano Firmware is latest version?
 
2) Audio Output selected to be ASIO?
 
3) DSD as DOP is deselected in the ASIO Output Options?
 
Yes - DSD 256 should play, on windows. On OSX, no DSD 256...as it is running on Core Audio.
 
Thanks.

 

[roamling]

wow, did not think that would work, thanks for the heads up!
I will try the settings as soon as I have the micro iDSD

 

[badkundi]

Hi,
 
I'm new to posting on this forum and my question maybe a little off the current topic for which I apologise. I was wondering if anyone would know how the headphone amp section of the ifi audio I-dsd micro is supposed to compare in terms of sound quality to the I-can. Also how would it perform with 600 ohm headphone loads. I can see that it very powerful, but not all powerful portables that I have heard have performed well with these higher loads. I own a range of headphones including HE-500 and Beyer DT880 600ohm and was thinking of taking the plunge with the micro i-dsd as it would hopefully satisfy my DSD home needs and my portable rig needs in one purchase. If anyone has any advise, that would be great.