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No love for IcePower?

Matias

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Ahem, March Audio
I mean ICEpower, as per the thread title, but yes, March Audio of course is another option for Hypex modules. :)
 

ahofer

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Not ICE related, but there’s currently someone on Audiogon spouting off on how No Class D amp can or will ever be able to power famous sub 2 ohm loads like Thiel 5/7 and Apogee. I think I saw 38 amps peak current on the latest Purifi module. If that can’t do it...
 

March Audio

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Not ICE related, but there’s currently someone on Audiogon spouting off on how No Class D amp can or will ever be able to power famous sub 2 ohm loads like Thiel 5/7 and Apogee. I think I saw 38 amps peak current on the latest Purifi module. If that can’t do it...
The Purifi is capable of 25 amps and stable into 2 ohms. All the The Hypex ncore amps can drive 2 ohms. Nc1200 is indeed capable of 38 amps. The nc2k can deliver 49 amps.

Basically that person is indeed talking bollocks.

I would add that IMO any speaker that has a sub 2 ohm load is a bad design.
 
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March Audio

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So using this link to calculate ICEpower 125ASX2 stereo SINAD into ASR standards (1 kHz, 4 ohms, 5 watts has THD+N 0.002% as per the green line on graph) gives SINAD = 94. Right?

View attachment 32492

If so, this would be right up there in the middle of the blue sector of the master SINAD chart for power amplifiers.

Not bad for a small, all-in-one (buffer+power stage+power supply), stereo $125 module! :D
I know I will be viewed as biased but I think the HF distortion level is pretty unimpressive.
 

Matias

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Yes, time goes by and technology improved, these ICEpower 6.67 kHz lines are not pretty, hence the need to update their modules.
 

VintageFlanker

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According to @amirm testing methodology: The THD+N of the AS1200 is at 5W / 4 ohms, 0.004% maximum. How this translate in SINAD?

So using this link to calculate ICEpower 125ASX2 stereo SINAD into ASR standards (1 kHz, 4 ohms, 5 watts has THD+N 0.002% as per the green line on graph) gives SINAD = 94. Right?

I didn't consider only the 1Khz tone (0.002%)... So, the SINAD of the AS1200 would be 94 dB as well for 1Khz 5W / 4 ohms.
 

DonH56

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IME most audio measurements provided (labelled) as THD+N are actually SINAD; they treat all except harmonic spurs as "noise". They take an FFT and RSS (root-sum-square) all bins save the fundamental tone's bin to do the math.

FWIW I reference IEEE Standard 1241 for ADC testing (there is a similar one for DACs but I do not remember the number).
 

sajunky

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1200AS is the only ICE Edge module in their line. Maybe the new chip is responsible for this improvement. But I don't understand why didn't they trickle down this tech to the lower powered modules yet... It's not like they don't have competition going on...
1200AS is using discrete components, it is expensive. They need a time to incorporate new logic in their new custom chip. When chip is ready, it will be deployed in lower priced models.

However considering competition, they may go ahead and try to reduce distortion @6.67kHz first.
 

peanuts

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The z-review of the PA-1


At around 20 minutes he gets into subjective SQ saying these amps add a bit if sibilance to the highs that his Crown 2502 does not. Perhaps Zeos is hearing the rise in THD at high frequencies viewed in the measurements above. That kind of cools my jets so far as buying a pair goes.

lol this idiot hooks an emotiva potmeter to the input of a poweramp (!) and ruins the impedance and frequency response completely. no idea how to work the products he reviews. if im not mistaken other icepower units have a minimum input of 6-8k or thereabouts, that needs control.
no input buffer on the board made by emotiva either. common practice for ALL other brands.
 

Ron Texas

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lol this idiot hooks an emotiva potmeter to the input of a poweramp (!) and ruins the impedance and frequency response completely. no idea how to work the products he reviews. if im not mistaken other icepower units have a minimum input of 6-8k or thereabouts, that needs control.
no input buffer on the board made by emotiva either. common practice for ALL other brands.

I believe the specified input impedance of the module is 47k ohms. Perhaps you can explain exactly what you mean in your comments, other than the "this idiot" part which I will not contest. However, I wonder what he is hearing is what some reviewers said about the Peachtree 150, which probably has the same modules.
 

Juhazi

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Yes, time goes by and technology improved, these ICEpower 6.67 kHz lines are not pretty, hence the need to update their modules.
I tested an Audiolab amplifier vs. ICEPower 50ASX2 module driving mid and tweeter of my active 4-ways (LR2@4000Hz) I couldn't hear or measure any difference in acoustic output. These have been power on 24/7 for six years now and I have spare modules, so...
 

Matias

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I tested an Audiolab amplifier vs. ICEPower 50ASX2 module driving mid and tweeter of my active 4-ways (LR2@4000Hz) I couldn't hear or measure any difference in acoustic output. These have been power on 24/7 for six years now and I have spare modules, so...

Nice. I also have 3 power amps based on 125ASX2. Still, if you have the opportunity to try out say a Hypex Ncore NC122MP, let us know. :)
 

sajunky

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I believe the specified input impedance of the module is 47k ohms.
47 kOhm is valid only for low frequencies. 125ASX2 and 50ASX2 input stage has 20dB/dec anti-aliasing LP filter that reduce impedance to 8 kOhms at 20kHz. This value is given in a datasheet. If you put potenciometer there, it would be a significant roll-off starting around 1kHz. But is is fine to drive the amp directly from a DAC without extra buffer.
 

Ron Texas

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47 kOhm is valid only for low frequencies. 125ASX2 and 50ASX2 input stage has 20dB/dec anti-aliasing LP filter that reduce impedance to 8 kOhms at 20kHz. This value is given in a datasheet. If you put potenciometer there, it would be a significant roll-off starting around 1kHz. But is is fine to drive the amp directly from a DAC without extra buffer.

That's a good answer. If I was to buy one of these I would put a passive high pass filter on the inputs. Since the filter is operating at low frequencies, would not have to worry (I hope) about this.
 

Juhazi

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Nice. I also have 3 power amps based on 125ASX2. Still, if you have the opportunity to try out say a Hypex Ncore NC122MP, let us know. :)
I have Hypex FA123 boards in another diy speakers, very nice product! But I don't believe that I can hear any difference to 50ASX2! I have decided to not do updates/swaps any more. I am too old to get fascinated by high performance numbers of dacs and amps. Still, we have now more options with amp boards, even better than ICEPower, today I would choose Hypex NCore modules or boxed like Emotiva PA-1 for woofers, but something with lower gain and power for mid-treble.

About the distortion of 6,67kHz - will you hear it is the question. These are power amplifiers feeding loudspeakers, so these distortion products are mostly above audibility and also out of band of many tweeters. Second harmonic is not considered bad at all and D3 of 6 is 18kHz...
Out of audio band distortion is potential problem with dacs feeding wide band amplifier circuits.
 
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chebum

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Since a few days ago I have begun to distrust the measurements of THD + N and SNR-A of the Polish page. The noise is too high in many of the products analyzed.

They do not use low pass filter Amir uses. This makes THD+N out of the chart high, especially for Class D amps.
 

maty

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When you compare those measurements made from some AVRs (class AB) that have been published on other sites, they move in the range of Amirm and not from the Polish magazine. I wrote them an email weeks ago telling them, with links to those reviews and they are still silent.

Moral: I do not trust any of the Polish magazine THD + N measurements, whether AVR or not.
 

chebum

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When you compare those measurements made from some AVRs (class AB) that have been published on other sites, they move in the range of Amirm and not from the Polish magazine.

IMO it makes little sense to compare measurements made by different people, using different equipment and test protocol.
 

maty

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The difference is too much. And I am talking about class AB.
 
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