ICEPower 125ASX2 Class D Amplifier Review

[ohskigod]

FWIW, a couple months ago I built a 125asx2 monoblock i planned to use as a bass amp, but then saw this thread and realized it had the new conductor technology (I previously had no idea, I bought it from partsexpress).......so of course I built another monoblock so i could have 2. They are currently burning in.....and will a/b them with my 1200as2 amp as well.

 

[Rac]

FWIW, a couple months ago I built a 125asx2 monoblock i planned to use as a bass amp, but then saw this thread and realized it had the new conductor technology (I previously had no idea, I bought it from partsexpress).......so of course I built another monoblock so i could have 2. They are currently burning in.....and will a/b them with my 1200as2 amp as well.

Have you confirmed your's are the new conductor version?
If the chip circled in red is rectangle like this one it's a conductor. If it's square it's the old one.

My 125asx2 conductor sounds every bit as good as my 1200as2 apart from it having less power. It also sounds the same as a friend's purifi 1et400a and hypex nc502mp, I tried as hard as I could to spot a difference when swapping them all but couldn't.

By the way. There is no "burn in" it will change nothing but waste power.

 

[PHD]

What's a "conductor version" in the context of this amp? I was going to order two units from Profusion.uk:

https://gb.profusion.uk/uk/icepower125asx2

How can I tell the version, and does it make any difference? I don't think the measurement results here do this great amp justice. It must be a bad sample or a build, and it is only for the stereo configuration, not the bridged configuration with Ghent Audio's preamp (SE to balanced).

 

[Rac]

The one tested here is two icepower generations behind.
They never made an edge version like the 1200as2, 400a2 and 300a2 but the latest 125asx2 has leapfroged those with the conductor version.
If you download a data sheet for the 125asx2 that is a v1.9 and compare it to the latest v2.2 from Icepower's website you'll see a big improvement.
My conductor 125asx2 still doesn't test as good as the data sheet but it tests better than the one tested here.
You may want to email the place you're buying it from and ask if it's the conductor/icc5 version.
I know for a fact all the current stock SoundImports have are the new ones.

 

[ohskigod]

Have you confirmed your's are the new conductor version?
If the chip circled in red is rectangle like this one it's a conductor. If it's square it's the old one.
View attachment 445438
My 125asx2 conductor sounds every bit as good as my 1200as2 apart from it having less power. It also sounds the same as a friend's purifi 1et400a and hypex nc502mp, I tried as hard as I could to spot a difference when swapping them all but couldn't.

By the way. There is no "burn in" it will change nothing but waste power.

yup, that is how I confirmed it. Had no idea until I saw the 2 pictures here. Ordered the second one from parts express hoping for the same result and low and behold it was. Maybe they are smart enough to not sell the old stock....or they ran out of it?

listening to music, even in the background, is never a waste of power .

 

[ohskigod]

What's a "conductor version" in the context of this amp? I was going to order two units from Profusion.uk:

https://gb.profusion.uk/uk/icepower125asx2

How can I tell the version, and does it make any difference? I don't think the measurement results here do this great amp justice. It must be a bad sample or a build, and it is only for the stereo configuration, not the bridged configuration with Ghent Audio's preamp (SE to balanced).

the picture there is the old version, though parts express has a picture of the old version and they shipped me the new version twice (1 month apart). Only way you will know for sure is to order it and roll dice or call them and hope they actually know.

 

[Matias]

What's a "conductor version" in the context of this amp? I was going to order two units from Profusion.uk:

https://gb.profusion.uk/uk/icepower125asx2

How can I tell the version, and does it make any difference? I don't think the measurement results here do this great amp justice. It must be a bad sample or a build, and it is only for the stereo configuration, not the bridged configuration with Ghent Audio's preamp (SE to balanced).

Check the previous page of this very thread, and the one below.

ICEpower Conductor

New tech from ICEpower announced. The prototype is already around SINAD 102 (1kHz 5W into 4 ohms) with ~300W (1% THD+N of 1kHz into 4 ohms) and no rise around the knee. And with 6.67 kHz riding along with the 1 kHz, the old limitations of HCOM seem to have been solved...

www.audiosciencereview.com

 

[TNT]

Have you confirmed your's are the new conductor version?
If the chip circled in red is rectangle like this one it's a conductor. If it's square it's the old one.
View attachment 445438
My 125asx2 conductor sounds every bit as good as my 1200as2 apart from it having less power. It also sounds the same as a friend's purifi 1et400a and hypex nc502mp, I tried as hard as I could to spot a difference when swapping them all but couldn't.

By the way. There is no "burn in" it will change nothing but waste power.

Does your 1200 measure as the spec sheet?

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[Rac]

Does your 1200 measure as the spec sheet?

//

Yes. That and my 400a2 are close enough to the data sheet.

 

[Sokel]

Does your 1200 measure as the spec sheet?

//

Yes. That and my 400a2 are close enough to the data sheet.

300a2 as well, agrees with datasheet's both SE and BTL .

 

[ohskigod]

Yes. That and my 400a2 are close enough to the data sheet.

assuming the 300 and 400a2 needs a separate power supply (as it isnt built into the boark like the 1200as2 etc), may I ask what power supply you used in your build?

 

[Rac]

assuming the 300 and 400a2 needs a separate power supply (as it isnt built into the boark like the 1200as2 etc), may I ask what power supply you used in your build?

I've made a 6 channel using a 1200as2 with a 400a2 powered off the 1200as2 and a 125asx2.
I was going to run 2 400a2's from the 1200as2 as one's only for the midrange and the other would be for the tweeters so there would be very little power usage from them but I thought I would give the new 125asx2 a go. The downside is there is no 12volt trigger option.

 

[TNT]

Yes. That and my 400a2 are close enough to the data sheet.

OK! So a bit of a mystery why the new 125 isn't up to spec... do you intend to investigate further - I mean you seem to have the measuring gear for it...

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[Sokel]

OK! So a bit of a mystery why the new 125 isn't up to spec... do you intend to investigate further - I mean you seem to have the measuring gear for it...

//

I would certainly mail them with the results, I mean the 6.67kHz performance was one of the strong points at their datasheet.

 

[Rac]

OK! So a bit of a mystery why the new 125 isn't up to spec... do you intend to investigate further - I mean you seem to have the measuring gear for it...

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Yes i have had a bit of a go. The other channel does test better but i put up the worst channels results.
I've tried moving around the input and output wiring, swapping the mains supply out of phase but nothing gets better really. I can make it worse by running the twisted output wires along side the 1200as2 but I only need to keep them a few cm away for that to be fixed. Turning the 1200as2 that's next to it off does nothing either.
There is a possibility the noise is a grounding issue as without the my e50 rca outputs plugged in it looks alot better but I can swap straight over to the 400a2 or 1200as2 and everything is perfect.
I'll be setting up another 125asx2 in a few weeks so I'll test that and compare them.

The power supply noise was sort of expected as that is the same as the original?
I'm impressed with the 1200as2 power supply in comparison.

I do wish all these data sheets would include a simple 1khz 5watt fft. Then you would get to see this stuff.

 

[TNT]

How is the 125 designed? Do one dare to hook the balanced in on the Scarlett USB sound card in high imp. mode, hooked up to a laptop on battery operation? I mean for say 5W in 8 ohm - 6,3V.... ?

Well, I do own a Cosmos but its not so easily accessible at the moment...

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[TNT]

Perhaps also

as without the my e50 rca outputs plugged in

Perhaps short the inputs?

//

 

[Rac]

Perhaps also

Perhaps short the inputs?

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Could be a good idea for a test.
I even tested it wired into my minidsp flex ht with it hooked up to the speakers. It was exactly the same.
One interesting thing is at even loud playing levels through the tweeters of say 1-2watts it has extremely low thd at any frequency so it really isn't a concern in the real world.

 

[SimonY]

Is the ICEpower webshop USD?

 

[Rac]

Is the ICEpower webshop USD?

Yes