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ICEPower 125ASX2 Class D Amplifier Review

Feanor

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I don't expect perfection, but I also consider the effects of the global coronavirus pandemic on businesses. I probably won't receive my second Ghent case - the mono one - for a couple of months. If a grounding point needs a bit of scraping or sanding to work properly, I can do that - especially considering the otherwise excellent quality of the cases for such a reasonable price.
Very likely my very delayed Ghent case is a Covid issue. It's just a bit unexpected that two identical packages mailed from the same place at the same time will arrive several weeks apart. If worse comes to worse I will order a replacement case from Ghent since they are the best option nonetheless.

Meanwhile I have done a little work with the one case I did receive pending the arrival of the 200ASC from Parts Express. Note the same-scale paper cutout I put in as a placeholder.

IMG_20200618_195609243.jpg
holder.
 

Paulmac

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Well I have this amp module (ASX125x2) which I put in a case and connected up. It sounded perfectly fine to me, clear dialogue while watching movies. My priority. For my primary needs, very good and easy to safely complete in a case. Then I compared it to a TPA3251 module from China, and well, you, know, for my needs (clear dialogue No.1) both amps were good. And that was a while ago now. Then I got an SMSL AD18 and that I thought was great. And now, quite some time later, I got a Aiyima AO4 completed amp for $60 Australian, and ok most people would think its as rough as bags compared to the ICEPOWER and the TPA3251 module. Even though it uses the same chip as that module. But to my ears, dialogue is clearer on the Aiyima. Maybe the treble is too pronounced for normal hearing people (but not for me.). So after selling my other amps, Im left with the Aiyima, and Im waiting on the Aiyima AO7 (TPA3255) which again I got for $A60. when that comes, Ill probably sell the AO4. Im having fun. Class D is neat. The specs of the Aiyima are probably awful. But I know when I can understand the spoken word in a movie. And when I cant. Texas Instruments chips are brilliant and the people in China who manage to build those chips into completed boards and housings which achieve what I need at such a low price deserve my thanks. No way could I design an amp board. The guys here who can produce better are awesome, Im not arguing with that. I cant do it though myself. Put this way, the amp I have now is perfect for old men with bad hearing because I can hear bright high end again. I dont know how many cats Ive turned deaf in my quest.
 
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Paulmac

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Very likely my very delayed Ghent case is a Covid issue. It's just a bit unexpected that two identical packages mailed from the same place at the same time will arrive several weeks apart. If worse comes to worse I will order a replacement case from Ghent since they are the best option nonetheless.

Meanwhile I have done a little work with the one case I did receive pending the arrival of the 200ASC from Parts Express. Note the same-scale paper cutout I put in as a placeholder.

View attachment 69625holder.
I heard from a seller based in China that at one stage China was short of shipping capacity for non medical stuff. And that caused delays. Plus the shut down in China. Plus the fact the people there involved in serving customers in the West must be pretty down about the bad press China gets from certain quarters in the international media. Its not easy for any person on planet earth. Australia had ships full of face masks and 747 filled with the same for a few weeks at one stage and not much else getting through.
 

Paulmac

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I am serious and no, it is not. Most of us can't even hear 20 kHz let alone its harmonic distortion that is included in those graphs.
I might get my hearing tested. I can probably hear up to 6khz, I dunno. Maybe I need ultrasonic electrodes in my brain to directly stimulate a HF response in my noggin. You cant forget the human/machine interface. We have different perceptions based upon individual sensitivities. I refuse to write a thesis on the subject though. There is something about class D that helps me. Dunno what it is .
 

Perfect_pint

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Yes, I'm new...first post...great forum BTW with some superb contributions. Been reading through this thread multiple times over the past few months. I'm trying to decide between the ASX125x2 or the 200ASC + 200AC for a lot more money. Looking through both manuals in detail there is no Auto off / on a feature on the ASX125x2. I'm currently using Marantz SR7013 in 5.2.2 set with a second Zone 2 with 4ohm Elac UB5's, so I'm looking for something to power my Zone 2 so I can free up 2 channels on my AVR for 2 more atom speakers. I have a separate AV room to hide my gear the I like the idea of Auto on/off instead of always power on for safety and power consumption (if idle on and auto-off standby has a difference in Class D?). Anyone played with both these modules and compared and is the extra power noticeable?
 

AlainF

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So, I ordered one of those IcePower 125ASX2 based power amps and finally received it after a few weeks' transit. It did show a minor cosmetic dent and arrived set up for 220 Volt, but thanks to helpful information found on this forum, I was able to change to 115 Volt quite easily.
I've set it up and been spending a good bit of time yesterday evening listening to various pieces of music, and I must say, I really like it too!
Among the notable improvements, lower end seems moth tight, and I'd say sound stage is more precise, deeper and wider. It also is dead silent, which was an issue I was experiencing with my aging Arcam Alpha, and made it ever more annoying to listen to music at low volume.
I also did some research on the subject of "fake" parts on these Ice amps found on eBay or Ali and assembled in China, and I believe the most common "issue" is that all these amp boards are older IcePower V1 generation with older chips and components, where the most recent V2 model can be had only from the manufacturer, and is quite a bit more pricy. There have also been reports of poorer reliability, and some have failed (blown) after a short period of use, but sound perfomance seems to be mostly aligned with the manufacturer's claimed specs.

Thanks again for all the extremely helpful information all of you, passionate audio lovers, share on this forum!
 

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Kegemusha

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Thanks for the review, how will this compare to the IceEdge that I think is in the XTZ edge A300 amp, or maybe is the same module?
I cant find info on the used module for the XTZ edge. Thanks for any info
 

AlainF

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Thanks for the review, how will this compare to the IceEdge that I think is in the XTZ edge A300 amp, or maybe is the same module?
I cant find info on the used module for the XTZ edge. Thanks for any info

I believe XTZ is using the ICEPOWER 300AS1 module in their amp.
https://www.xtzsound.com/product/edge-a2-300
https://icepower.dk/products/amplifier-power-modules/as-series/
The XTZ should surpass the 125ASX2 based amps on just about every parameter. It's also a bit more pricey at +/- $500. It has excellent reviews.
I did consider buying it, but given my system, thought I'd save $300 and get the cheaper 125ASX amp first.
My next splurge is likely going to be a better pair of bookshelf speakers, although I must say the Klipsh RP-600M give me ample listening joy (despite the speakers scoring pretty low on the measurements Amir delivered on this forum.)
 

snickers

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I believe XTZ is using the ICEPOWER 300AS1 module in their amp.
https://www.xtzsound.com/product/edge-a2-300
https://icepower.dk/products/amplifier-power-modules/as-series/
The XTZ should surpass the 125ASX2 based amps on just about every parameter. It's also a bit more pricey at +/- $500. It has excellent reviews.
I did consider buying it, but given my system, thought I'd save $300 and get the cheaper 125ASX amp first.
My next splurge is likely going to be a better pair of bookshelf speakers, although I must say the Klipsh RP-600M give me ample listening joy (despite the speakers scoring pretty low on the measurements Amir delivered on this forum.)


Do you hear any hiss from your Klipsch's together with the IcePower?
And btw, have you connected it over XLR or cinch?


King Regards :)
 

Kegemusha

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Thanks AlainF, Last black Friday the Edge was about €390 here, wait some time and buy it then ;)
 

AlainF

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Do you hear any hiss from your Klipsch's together with the IcePower?
And btw, have you connected it over XLR or cinch?


King Regards :)
Connectors are cinch (RCA). There no baseline noise that can be heard from any listening distance when the RP600 are connected and powered by the IcePower amp alone (close to none), but my Arcam preamp does generate some noise, though also imperceptible from a typical listening distance. When used as the amplifier, the Arcam did generate baseline noise that was definitely perceptible when listening to music at low volume, which is one of the primary motives for me to acquire a separate power amp, hence the IcePower purchase. Definitely happy with it.
 

tetrode

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I've read through the entire 10 pages of this excellent and very helpful thread but still have a question regarding 125ASX2 amps in BTL configuration. I'm considering assembling a pair of mono amps based on this ICEpower module. Since my source will be balanced, wiring the board should be straightforward:

bnIBSHV.jpg


What has me puzzled is how the 125ASX2 can be configured to accept either SE or balanced input using Ghent's RTX module. The module seems to have one input (single ended) and one output (balanced) yet I see finished amps with rear panel toggle switches allowing for either RCA or XLR input selection. How is this accomplished?

After re-watching Guntars Smits YT video comparing ebay sourced 125ASX2 modules to the genuine article (
) I'm feeling a bit more confident about giving the Chinese clones/knockoffs a try.
 

preload

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As an alternative to DIY, there's also the Bel Canto Ref 500S, which is based on a pair of 125asx modules. The chassis is very nicely built. It also comes with WBT binding posts and you don't have to worry about getting fake modules. They usually go for under $1000 USD used.
 
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nerone

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I am thinking of selling my Elipson MC1 amplifier with IcePower 125ASX2 module
 

Perfect_pint

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Yesterday I built my second ice power amplifier after the first sounded very impressive and was so easy to wire up. These are in a temporary case for now (CNCed Di-bond with glue and tape) untill I get some time to machine and bend some aluminum cases. If anyone's got any questions let me know.
IMG_20201012_080154.jpg
 

Perfect_pint

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I believe XTZ is using the ICEPOWER 300AS1 module in their amp.
https://www.xtzsound.com/product/edge-a2-300
https://icepower.dk/products/amplifier-power-modules/as-series/
The XTZ should surpass the 125ASX2 based amps on just about every parameter. It's also a bit more pricey at +/- $500. It has excellent reviews.
I did consider buying it, but given my system, thought I'd save $300 and get the cheaper 125ASX amp first.
My next splurge is likely going to be a better pair of bookshelf speakers, although I must say the Klipsh RP-600M give me ample listening joy (despite the speakers scoring pretty low on the measurements Amir delivered on this forum.)
I have both a 300AS1 + 300A1 amplifier and the 125ASX2. I have no equipment for any measurement but I can say there is a noticeable performance difference in the bass. Slightly more tight and punchy on the 300AS1 as expected. Both a lot more detailed compared to Marantz SR7013 and also less warm which is normal for class D vs A/B. Definitely recommend picking up and 125ASX2 for a play. If anyone noticed.... Yes, I have no shielding on my signal input as I'm used RGB cable temporarily.
 
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Perfect_pint

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I've read through the entire 10 pages of this excellent and very helpful thread but still have a question regarding 125ASX2 amps in BTL configuration. I'm considering assembling a pair of mono amps based on this ICEpower module. Since my source will be balanced, wiring the board should be straightforward:

bnIBSHV.jpg


What has me puzzled is how the 125ASX2 can be configured to accept either SE or balanced input using Ghent's RTX module. The module seems to have one input (single ended) and one output (balanced) yet I see finished amps with rear panel toggle switches allowing for either RCA or XLR input selection. How is this accomplished?

After re-watching Guntars Smits YT video comparing ebay sourced 125ASX2 modules to the genuine article (
) I'm feeling a bit more confident about giving the Chinese clones/knockoffs a try.
What has puzzled me is the speaker's output, the "pin4" is positive when in stereo mode but negative in bridged mode. For the interest of this forum and curiosity, I will give this a try, Might have a switch somewhere to test. What's the worst that can happen..blow a speaker or amplifier? :) Locked inside awaiting covid-19 results anyways!
 

tetrode

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Google FTW! I found the answer to my question regarding the switchable RCA and XLR configuration when using Ghent's RTX module. A member of another forum queried Ghent who supplied this diagram:

681-BTL-Sample-wiring.png


Hope this helps others as it has helped me. A special thank you to the original poster of this diagram.
 

DWPress

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I just scored 2 Featheramp FA-500s on Amazon for $106 each. Going to run them BTL for my woofers. I love this forum.
 
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