[maty]

https://icepower.dk/about/#contact
ICEpower HQ info@icepower.dk


Subject: IcePower 1200AS2 and phase shift, again

Hi from Spain,

Two weeks ago I send you a mail with a question about the phase shift of
IcePower 1200AS2 module.

I opened a thread about the question here in Diyaudio.com

Phase shift in class D amplifiers. How it affects the sound?

http://www.diyaudio.com/forums/class-d/321578-phase-shift-class-amplifiers-affects-sound.html

[IMG]
http://maty.galeon.com/WP-imagenes/hard/IcePower-1200AS2-output-impedance-phase.png


Simple question:

Is the output phase of the IcePower 1200AS2?


If not, which?

Please

[bavmike]

They probably have bigger fish to fry than answer stupid questions. Like keeping up with the exploding demand from OEM’s who have listened to them.

[maty]

In Spanish there is a saying: quien calla otorga -> who keeps silent says yes.

[Hear Clifford Brown]

I also have a Mivera SE amp with the new ICE board.  I'm in the "measurements be damned' camp and this new amp sounds better to me than all the tube amps I tried.  The list is long, but they were used with different speakers than I have now, so to say the Mivera amp sounds better than all of them may not be completely valid.  My current speakers are Spatial M3TM's and prior to the Mivera amp was using a Dennis Had Inspire amp (17 watts with KT88's).  I always thought it sounded great but these speakers really came alive in every way with the Mivera amp.   

[bavmike]

The measurements of this amp are actually outstanding. We just have a case of someone having no idea how to interpret them.

[Hear Clifford Brown]

I wasn't implying the measurements of this amp are good or bad, just that I haven't ever paid too much attention to measurements, at least not so much anymore.  Early on like 18 years ago, when I started becoming an audiophile instead of just a guy who is really into music, I would read professional reviews in hard copy magazines.  Some of those reviews included measurements.  Buying decisions were partially dependent on measurements then, but more on what the reviewer liked about the sound.  Now I rely on what people who have the component say about it on forums and in reviews. 

[Tyson]

I wasn't implying the measurements of this amp are good or bad, just that I haven't ever paid too much attention to measurements, at least not so much anymore.  Early on like 18 years ago, when I started becoming an audiophile instead of just a guy who is really into music, I would read professional reviews in hard copy magazines.  Some of those reviews included measurements.  Buying decisions were partially dependent on measurements then, but more on what the reviewer liked about the sound.  Now I rely on what people who have the component say about it on forums and in reviews. 

Hey, that's similar to me!  Although nowadays I tend to just wait for something exceptional to show up on the used market, try it out in my system for a few weeks & then re-sell it if it's not as good as what I already have.  Takes a lot of the guesswork (and financial stress) out of the whole process. 

[timind]

Hey, that's similar to me!  Although nowadays I tend to just wait for something exceptional to show up on the used market, try it out in my system for a few weeks & then re-sell it if it's not as good as what I already have.  Takes a lot of the guesswork (and financial stress) out of the whole process.

That's been my method for quite a while now. I've listened to a lot of well reviewed amps that have left me cold. I don't like to talk negative about any product, but I will give my opinion freely. Throughout all of my listening I would say the price of an amp doesn't really mean that much as I have fallen in love with the sound of some pretty inexpensive amps. Maybe my ears are crap.

[maty]

I bought my second hand class AB AV Marantz SR4500 for less € 120. After my cheap tweaks and the great improvement in the cleanning the mains power it sounds very good in my cheap second system. Well, one of the weakness was the cheap -and dirty- trimpot (bias adjust) - the damn Marantz cut of expenses where it should not be. Now I do get excited much more easily and more often than years ago! To have clean power is very important.

https://nauscopio.wordpress.com/2012/09/08/receptor-av-marantz-sr4500-comprado-al-forero-audiomalaga-de-audio-planet/

[OzarkTom]

Hey Maty, check out this new XTZ Edge Icepower amp for 495 Euros. It is not Ice Edge, but it is the Icepower 300as module. A German mag gave it a very glowing review. Use the 30% off coupon and it is less than $500. Sounds like a heck of a deal to me. Made in Sweden and very nice looking.

https://www.xtzsound.eu/reviews/edge-a2-300

Correction. looks like the 30% off coupon has expired. Spain total is 505 Euro.

[maty]

Hey Maty, check out this new XTZ Edge Icepower amp for 495 Euros. It is not Ice Edge, but it is the Icepower 300as module. A German mag gave it a very glowing review. Use the 30% off coupon and it is less than $500. Sounds like a heck of a deal to me. Made in Sweden and very nice looking.

https://www.xtzsound.eu/reviews/edge-a2-300

Correction. looks like the 30% off coupon has expired. Spain total is 505 Euro.

Je, weeks ago I change mails with the founder, Olle. And I suggested the 1200AS2 module. With a steel box and its production scale could offer it at a much lower price than its competitors.

I always like to contact and talk with people with decision-making ability.

[Roninaudio]

I think we are missing the point here.  I mean here are some Class D products at $96K plus.  Now those have to be good right? (lol)

https://blinkhighend.com/shop/components/aavik-m-300-power-amplifier/

[poseidonsvoice]

I think we are missing the point here.  I mean here are some Class D products at $96K plus.  Now those have to be good right? (lol)

https://blinkhighend.com/shop/components/aavik-m-300-power-amplifier/

I believe the design to be class A/AB.

https://aavik-acoustics.com/products/u-301.html

https://www.audiogon.com/listings/solid-state-mono-power-amps-class-a-2017-12-20-amplifiers

In addition it is very heavy, has a low input impedance of 11k-12k ohms and puts out about 300-580 watts/ch. Pretty chassis with obviously covered heatsinking. The overall gain is slightly more than the industry standard at 30dB instead of 26 dB (a minor consequence other than increased noise). The output impedance is a low 1 milliohm with a damping factor of 8000.

It appears to be a competent design that is overpriced but without a subjective audition and far more detailed measurements on an AP or equivalent there is no way to distinguish it from other companies building equally competent products without the fancy chassis.

I believe their U-300 model which is an integrated amp at $30k is Class D.

http://www.theabsolutesound.com/articles/aavik-acoustics-u-300-integrated-amplifier/?page=4

Best,
Anand.

[maty]

I just send again the same mail to Icepower.

Why? There was a problem on my part because I sent it ... encrypted. 

Off course, the first mail was not encrypted.

So I put the days counter to zero.

PD: my public key https://nauscopio.wordpress.com/about/

[maty]

mocenigo says:

http://www.diyaudio.com/forums/vendor-s-bazaar/281361-hypex-ncore-nc500-build-post5433261.html

You can go to the Apollon site and there is a little chat widget. I asked for confirmation that they were not using RF/EMI filters on the AS1200 amp. I paste here their reply verbatim

We don’t use any EMI filters in our amplifiers. EMI filters are not the best choice for SMPS power supplies.

For our Icepower models, we don’t even use an additional fuse. We use a Furutech mains input socket connected direct to the modules.

Corrected the first post.

[maty]

IcePower 700AS2. Frequency and Phase.

Icepower 1200AS2. Impedance and Phase.

[JohnR]

Once again, these graphs are not comparable. (I will try to explain.) The first graph is frequency response - this has two components: magnitude (or amplitude) and phase. Definition:

"Frequency response ... is a measure of magnitude and phase of the output as a function of frequency, in comparison to the input."

(https://en.wikipedia.org/wiki/Frequency_response)

The second graph is the output impedance - this also has magnitude and phase. However this is not the same "phase"! From Wikipedia:

"Impedance extends the concept of resistance to AC circuits, and possesses both magnitude and phase, unlike resistance, which has only magnitude."

(https://en.wikipedia.org/wiki/Electrical_impedance)

The "phase" shown in those two graphs is a completely different property. (Please try and absorb this....)

[maty]

I think you need to go to the basis:

https://en.wikipedia.org/wiki/Complex_number

https://en.wikipedia.org/wiki/Direct_current

https://en.wikipedia.org/wiki/Ohm%27s_law

[JohnR]

Yes, a complex number can be represented as magnitude and phase, and Ohm's law defines the relation between a voltage across an impedance and the current through it. So ....

I'm not sure what part of this you are blocked on, but maybe you could just read the labels - see how one is "Frequency Response" (NOT "Frequency and Phase") and the other is "Output Impedance" (NOT "Impedance and Phase") ? They are measurements of different quantities.

[maty]

* Class A and class AB, R is R  (almost R). Usually the phase varies is in little interval -> you can consider that the impedance is basically resistive. Everyone has it assumed and is not usually specified.

P = Vdc*Vdc / R


* Class D, R is Z, complex. That is the problem with the IcePower 1200AS2 and others class D modules and not only the frequency peak of old class D or the noise at HF.

P = Vdc*Vdc / Z

One thing is a little interval like 6 degree, other different thing is 34 or 70 degree. How much affect in the sound? I do not know. Always I think in very good recordings without electronic/computer instruments, autotune.... and lot of studio processing.

Phase varies -> wich is the natural timbre of a violin, piano, voice... ?

1200AS2: About 40 degree at 1 kHz.