iFi Audio Pro iDSD discussion thread

[Totsipaki]

I would say November as an optimistic estimation..

 

[dan.gheorghe]

   
I asked about the 140dB months ago too after seeing such a high number for the first (and only) time on a headphone amp. Other specs appear to be very different (or heavily revised) as well.
 
Site shows >14,000mW max balanced but posted specs show >6000mW?
 
Which is correct and the why the huge variance? Hope it wasn't to spur initial sales with over-hyped specs.........
 

I have received an answer from iFi:

 
The prototype measurements where stated against a different reference value (400mV) than the final ones (20V).

We changed the published values to be stated in line with those by most of our competitors.

 

[gr8soundz]

Thanks.
 
So that means iFi published (and still have) prototype specs/measurements on their site based on boosted reference levels.
 
I realize there is no law on how specs are determined but not cool to give numbers (which some of us use for comparison in blind purchases) that are so far out of line with comparable products.
 
The numbers don't decide how well the amp performs but I feel bad for those who paid almost 2 grand and thought they were getting 14W of power only to find it's more like 6W (only 2W more than my iDSD Micro; assuming those specs aren't boosted too). Still very powerful for a headphone amp but I bet there are a few HE-6 and K1000 owners out there who may have something to say.
 

 

[iFi audio]

   
I asked about the 140dB months ago too after seeing such a high number for the first (and only) time on a headphone amp. Other specs appear to be very different (or heavily revised) as well.
 
Site shows >14,000mW max balanced but posted specs show >6000mW?
 
Which is correct and the why the huge variance? Hope it wasn't to spur initial sales with over-hyped specs.........
 

 
Hi,
 
>  why the huge variance?
 
First, some of the early figures (like those given in Jannary 2015) were based on a very different circuit design, which has since been superseded and which performed very differently.
The current iCAN Pro has ALMOST NOTHING retained from the original design. We did state this upfront a while ago, it is on record! 

 
The first design was in effect a balanced implementation of the iCAN micro circuitry with some additional improvements (all of which got applied to the iCAN SE). Instead the final iCAN Pro is a ground-up new design with rather different circuit design (all discrete, higher voltages in the internal power-supply etc.). and hence a very much different performance.
 
The published specifications are based on the test results of the final production units using our Audio Precision 2 test-set the same as they are delivered to customers and supersede any earlier figures.
 
Second, while preparing final numbers we took notice that while we have over time used reference levels for headphone Amplifiers that were derived from the work of a certain enthusiast who published extensive headphone amplifier measurements on line. We felt his choice of reference levels made good sense in practice. 
 
However no-one else seemed to have been prepared to state their products specification on an IDENTICAL basis. So with recent products we have reverted to the general industry practice of stating numbers, which for SNR/Dynamic range are generally taken at maximum output, not at an (not entirely arbitrarily low) 400mV reference level and stating output power at the lowest impedance supported. So our numbers are directly comparably with those published by our competitors.
 
Looking at some competing professional Headphone Amplifiers we find the following stated and specified DNR:
 
Product 1: 129dB(A)
Product 2: 135.5dB(A)
Product 3: 131dB(A) (normalised to maximum output)
 
The iCAN Pro has significantly lower noise and higher maximum output than the competing products, hence the greater numbers.

SNR may be specified against maximum output, as dBu (against a 0.775V output) or as dBV (against a 1V output) or against any arbitrary reference. Suitable standard absent the industry practice everyone is free to pick a reference the like. It does not matter as long as the reference level is known it is easy to compare figures like for like.
 
The iCAN Pro in 0dB Gain mode, Solid-State, Balanced in/out is specified referenced to 20V output for SNR, which results in 147dB, which equals the Dynamic range measurement. If comparison to any other reference level is desired, simply calculate the difference between 20V and this desired reference level in dB and subtract/add the result. 
 
For example, the difference between 1V and 20V is 26dB, so if we want to compare to 1V reference level the iCAN Pro would have -121dBV (A) SNR.
Noise scales with gain, so more gain equals the same amount more noise and unbalanced operation is noisier.
 
Cheers.

 

[iFi audio]

  Thanks.
 
So that means iFi published (and still have) prototype specs/measurements on their site based on boosted reference levels.
 
I realize there is no law on how specs are determined but not cool to give numbers (which some of us use for comparison in blind purchases) that are so far out of line with comparable products.
 
The numbers don't decide how well the amp performs but I feel bad for those who paid almost 2 grand and thought they were getting 14W of power only to find it's more like 6W (only 2W more than my iDSD Micro; assuming those specs aren't boosted too). Still very powerful for a headphone amp but I bet there are a few HE-6 and K1000 owners out there who may have something to say.
 

 
Hi,
 
The power output from the iCAN Pro and iDSD micro are determined in precisely the same way and both numbers hold as published.
 
The numbers for the iCAN Pro are shown both for Balanced operation (where it is around three times as powerful as  iDSD micro and iCAN SE micro) and Single-Ended (where it is marginally more powerful than iDSD micro and iCAN SE micro).
 
For higher impedance headphones (above appx. 32 ohm) all iFi Headphone Amplifiers are limited in output only by the maximum Output voltage, power becomes irrelevant (the Amplifier supplies as much power as demanded by the impedance of the headphone). 
 
So if using balanced outputs and headphones with > 32 Ohm impedance the iCAN Pro will deliver the full 20V or the equivalent a Speaker amplifier rated 50W/8Ohm driving the same headphone directly.
 
Only for very low impedance headphones (< 32) is there any limitation of the output power due to a lack of available current. The iCAN Pro can deliver around 1,300mA repetitive peak current. This a much greater amount of current than we have found with other headphone amplifiers. 
 
Ever which way, in balanced mode the output levels suffice in our testing to drive the AKG K1000 into the mechanical limits of the driver before clipping.
 
Thanks.

 

[gr8soundz]

Thanks for the detailed clarification.
 
Wasn't aware of the power limitations below 32 ohms but will keep it in mind when using my Micro.
 

 

[iFi audio]

  Thanks for the detailed clarification.
 
Wasn't aware of the power limitations below 32 ohms but will keep it in mind when using my Micro.
 

 
The 'power limitations' are already accounted for in the rating. If 20V where available with 16 Ohm the power would be 25,000 mW, as only 14,000 mW per channel are rated, this includes the de-rating for the limited current. Equally for the iCAN SE micro and iDSD micro we would expect > 6,250 mW, as the rating is only 4,000mW it is already de-rated.
 
Given that all low impedance (< 32 Ohm) headphones we know are very efficient it is highly unlikely you ever run into power limits. In fact the only Headphones that require the iCAN SE micro or iDSD micro to be driven near limits are the AKG K1000 and HiFiman HE-6 and a small number of old 600 Ohm Studio Headphones.
 
Well, suppose you could take a pair of 16 Ohm BBC LS3/5A Studio monitors, attach a head bracket to them and put them on your head.
With only around 94dB/1,000mW you would only get 100dB peaks which may not be quite loud enough.
 
If you took Shure SE535-LTD IEM's (which are 36 Ohm rated) instead the maximum output from iCAN SE micro or iDSD micro would produce 153dB - enough to cause necrosis in the tissue inside the ear.

 

[Esprit]

Is it an insane idea to use the Pro iCAN as preamp with active monitors (no mono, no phase button, no balance control...)?

 

[gr8soundz]

  Is it an insane idea to use the Pro iCAN as preamp with active monitors (no mono, no phase button, no balance control...)?

 
Why not use the iTube instead. Same tube as the Pro and designed as a Class A buffer/pre-amp (with gain settings) for speakers (although I use mine connected to a headphone amp).
 
If you don't need the balanced in/out of the Pro no need to spend 6x the price.
 

 

[jbarrentine]

I don't understand the ifi product lines at all. There's no "good/better/best" differentiation anywhere on the site and listings seem strewn together. 
 
Can someone break down what would be useful from a desktop perspective? Especially without a battery, but with one if necessary.

 

[Cotnijoe]

I don't understand the ifi product lines at all. There's no "good/better/best" differentiation anywhere on the site and listings seem strewn together. 

Can someone break down what would be useful from a desktop perspective? Especially without a battery, but with one if necessary.

Nano is for portable use and, with the exception of the USB3.0, have battery.

Micro is for desktop use without taking up a mad amount of space. In fact, there's a nice rack that helps safe space and make your stack look nice and pretty. They're still small enough that they're also fairly transportable.

The new pro series is the flagship and goes all out. They're bigger and take up more space than the micro series, but still not as big as other desktop components. There's also quite a bit of technology that went into the Pro iCAN.

The Retro stereo 50 is an all in one sort of device that covers both speakers and headphones as well as other really nifty functions such as bluetooth.

 

[jbarrentine]

Nano is for portable use and, with the exception of the USB3.0, have battery.

Micro is for desktop use without taking up a mad amount of space. In fact, there's a nice rack that helps safe space and make your stack look nice and pretty. They're still small enough that they're also fairly transportable.

The new pro series is the flagship and goes all out. They're bigger and take up more space than the micro series, but still not as big as other desktop components. There's also quite a bit of technology that went into the Pro iCAN.

The Retro stereo 50 is an all in one sort of device that covers both speakers and headphones as well as other really nifty functions such as bluetooth.

 
Ok, that makes more sense. What I don't see and am interested in is an all in one unit like the Micro iDSD but without a battery.
 
I can't help but think that a battery in such a thing plugged up all the time is a needless fire hazard, especially as I would never ever use it in a portable manner. 
 
Why doesn't such a product exist? Am I missing something?
 
Many thanks for your reply Cotnijoe.

 

[Cotnijoe]

 
Ok, that makes more sense. What I don't see and am interested in is an all in one unit like the Micro iDSD but without a battery.
 
I can't help but think that a battery in such a thing plugged up all the time is a needless fire hazard, especially as I would never ever use it in a portable manner. 
 
Why doesn't such a product exist? Am I missing something?
 
Many thanks for your reply Cotnijoe.

 
the Nano iDSD has a bettery. The Micro series iDSD is what you're looking for if you want to optimize performance and ditch the battery.
 
The naming can get a little confusing since the product names are the same, but the series are different haha. Happy to help 

 

[jbarrentine]

   
the Nano iDSD has a bettery. The Micro series iDSD is what you're looking for if you want to optimize performance and ditch the battery.
 
The naming can get a little confusing since the product names are the same, but the series are different haha. Happy to help 

 
But the iFi site says the Micro iDSD has a battery too :\

 

[Cotnijoe]

 
But the iFi site says the Micro iDSD has a battery too :\

 
Oh geez yea my brain is scattered. It even charges whatever device you connect it to haha.
 
I guess then you can wait for the upcoming Pro iDSD. There's some info regarding it now if you dig deeper into this thread.
 
Time to sleep... ... ...