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ICEPower 125ASX2 Class D Amplifier Review

EB1000

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Hi

Anyone has the 125ASX2's designer manual? Ghent from Ghent Audio sent it to me once but I can't seem to find the file or the original email. I can't find it online (only the 50ASX2 can be found).

Thanks
 

Matias

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Matias

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Just a small question: is this simply switching noise? I just connected an oscilloscope to the output of the amp in BTL mode.

View attachment 92730
Do the math: 1 uS per division, the wavelength period is about 2 divisions, so 2 uS.
f = 1/T = 1/2 x 10^6 = 500 kHz. Bingo, switching frequency.
 

guy1846

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this is what i have measured ch1 200mv ptp and ch2 300mv ptp switching noise after a L C filter that i have set on each output.
Do the math: 1 uS per division, the wavelength period is about 2 divisions, so 2 uS.
f = 1/T = 1/2 x 10^6 = 500 kHz. Bingo, switching frequency.
on my ACE125 483 Khz but 2 V ptp so mutch. simply for test i put a L C component at both outputs and ch1 200mv and ch2 300mv ptp.
i try later some pictures, dosn't work, to big. maybe later this evening.
 

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LBec

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I love Tektronix scopes.

Anyway, I don't understand why Class D amplifiers are tested using purely resistive loads.

I can sort of get why it can make sense with a class A or AB amp since for the most part they tend to have very low impedance outputs and are usually designed to put out a constant voltage.

My general understanding is the output of Class D is a set of pulses wave that go through an LC filter. I figure there is some interaction with the varying impedance of the speakers.

Why aren't Class D amps tested with a mock-up of a speaker (eg, a mix of resistors, capacitors and coils) to see how it affects output?
 

Doodski

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I love Tektronix scopes.
I used to go through calibration gear as fast as I could afford it. I've had several CRT Tektronix scopes and my fav CRT O-scope is this.( I've had HP CRTs too and some of them have some pretty nice traces too.) I suppose I could get with the times and think about a digital O-scope but for troubleshooting stuff a CRT is so fast and easy to operate.
7603-4trace.jpg
 
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LBec

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Tektronix scopes were definitely the gold standard. High quality products.
 

antennaguru

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I still use two older Tektronix scopes that I own - they have the best trigger circuits!

I built three (3) of the stereo 125ASX2 V1 boards into project amplifiers over the past 4 or so years. All three (3) of them still are working fine, with no troubles yet. Two of the three have a second board inside the case to provide an input buffer stage, so they all sound a little different. No complaints here, and glad I saved money and bought the much cheaper early boards via ebay...
 

Paulmac

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I had the same icepower module a while ago. I preferred the TI tpa 3255 (even when bought as an amp module from China). The downside is the problem with the tpa 3255 is sourcing a decent single rail power supply, whereas the icepower has a decent power supply onboard. Sadly Ive stopped using Class D amps. Im using a Denon AV amp due to the clamouring of other family members for an av amp. https://www.ti.com/lit/ds/symlink/t...54328&ref_url=https%3A%2F%2Fwww.google.com%2F
 

Phn2

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I have two working in btl with the ghent se>btl board.
Now building se stereo version via another board, but cant make it start in stereo.
When swithing the new board, with one of my old ones, it works in the btl cabinet.
Does stereo need buffer to work?
 

MenloBob

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I have two working in btl with the ghent se>btl board.
Now building se stereo version via another board, but cant make it start in stereo.
When swithing the new board, with one of my old ones, it works in the btl cabinet.
Does stereo need buffer to work?
How do you have Pin1 on the 8 pin signal connector wired? Should be no connection for stereo and tied to ground for BTL.
 

Perry Po

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Ice power 125asx2
I'm a new member. I just bought a Ice power 125asx2 from ebay. After simple hooked up with RCA anolog in, turn on power but no sound. I can measure +/- 24V out and high voltage on 3 pins transistor. So can someone solve this problem? I wonder the input connector (pin 2) enable/disable setting?
Perry
 
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