JIMK04
Your voltage looks within acceptable range for utility service range at time stamp. Check at time when it gets noisy to see if you are having either utility service voltage low drop or voltage high spikes.
Next it could be that there is harmonic noise on your utility input voltage. A harmonic noise filter inline before transformer could help clean this up.
The amplifier should be properly grounded to help get rid of ghost voltage loops.
Worst case scenario is some part of your amplifier is not rated for voltage input or rated amperage load.
There is an optimum design size for low impedence design that can handle full load design reliability.
You could lower your torroidal transformer voltage to help correct possibly.
Better heak sink or thermal insulate heat transfer materiak between chip/hit spot and heat sink. may help if overheat sink.
Since it happens at different times of the day it may be utility service related
More troubleshooting required.
Your voltage looks within acceptable range for utility service range at time stamp. Check at time when it gets noisy to see if you are having either utility service voltage low drop or voltage high spikes.
Next it could be that there is harmonic noise on your utility input voltage. A harmonic noise filter inline before transformer could help clean this up.
The amplifier should be properly grounded to help get rid of ghost voltage loops.
Worst case scenario is some part of your amplifier is not rated for voltage input or rated amperage load.
There is an optimum design size for low impedence design that can handle full load design reliability.
You could lower your torroidal transformer voltage to help correct possibly.
Better heak sink or thermal insulate heat transfer materiak between chip/hit spot and heat sink. may help if overheat sink.
Since it happens at different times of the day it may be utility service related
More troubleshooting required.
Jimk04:
I had a similar problem when I ran a test amp that was just sitting on a wooden bench top running for several hours. It was starting to become dry in my house because I had turned central heating on so I presumed it could be a static charge buildup over time. Once I grounded the amps the popping went away.
2nd thought..and I mean no disrespect, but why don’t you only turn the amp on when you need it instead of running it 24/7? I know you want to solve the popping issue but try giving the unit more “rest" as you put it.
With respect,
Pete
🙂
I had a light infrequent pop before I bypassed everything up to the blocking caps. This also reduced the heat of the heat sink from very hot to warm.
Greetings.
I have a few questions about this amplifier.
I connected it to a 200 watt 36 volt power supply.
When a signal is applied to the input, the amplifier goes into protection ...
What could be the problem?
Second question.
How to connect the load at PBTL?
How do I apply the input signal (third question)?
P.S. what power supply do you use with this amplifier?
Sincerely, Mykola.
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Yes, reported by myself and forum members dubai2000, chips666, bisouxxx, vitopro, and Peterwitkin.
Now we keenly await your report!
Nice. I am curious of what you got.
I get 6.67Khz 10W 8R at 0.001 THD+N (-100) harmonic dominated
1Khz at (THD) 0.00013 (-117) and 0.0006 THD+N (-105) noise dominated .
I am still improving those numbers.
Of course I am using my own buffers . (yes result is with buffers)
One last thing...if you are only testing now you might not get good test data. We tested many times the THD vs different values of PFFB (and yes they make a big difference)
My PFFB is custom .
I get 6.67Khz 10W 8R at 0.001 THD+N (-100) harmonic dominated
1Khz at (THD) 0.00013 (-117) and 0.0006 THD+N (-105) noise dominated .
I am still improving those numbers.
Of course I am using my own buffers . (yes result is with buffers)
One last thing...if you are only testing now you might not get good test data. We tested many times the THD vs different values of PFFB (and yes they make a big difference)
My PFFB is custom .
So we can compare with Purifi + Bosc Gan modules, what do you get for this ?
Purifi :
1W, f=20-20kHz 0.0007 % into 8Ω
10W, f=20-20kHz 0.00029 % into 8Ω
100W, f=20-20kHz 0.00017 % into 8Ω
SNR A-weighted 4Ω 131 dB
Loop gain 75DB
Bosc Gan :
THD @ 10W: <0.0013% for 20Hz - 20kHz into 8Ω
THD @ 75W: <0.0050% for 20Hz - 20kHz into 8Ω
THD @ 150W: <0.015% for 20Hz - 20kHz into 8Ω
SNR A-weighted 4Ω 121 dB
Loop gain NC
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D
Deleted member 148505
Hello Daniboun
The numbers above are incorrect.
Purifi Amp has about 0.003 THD+N 20-20Khz 5W to 133W.
Bosc Gan , depends on what you see. As far as THD levels we beat them already (above numbers)
Our amp will be independently verified by Amir and I guarantee that our numbers willl be 2-3db better (since our AP floor is not as good)
At last , this is not about THD only. The SQ of a class d is not only AP numbers but multiple noise reduction techniques .
For those of you that know our TPA3118 design ,or for anyone else , you can check indepandant reviews and measuring on Amir site. We have reduced noise on output for example , something that's not taken into consideration on those forums.
Yes DrMordor design seems to be very competent , but experience in class D is crucial . Show me the noise on output , EMI levels , THD. Once you can tame those you can have a good sounding Class D design
As for us , we are still doing the incremental work on our AMP and when its ready we will have some units sent to test.
Yes you can use loop gain to reduce THD and the math makes perfect sense. However we approach this differently. Make a LLC quasi resonant, dual power with noise at 1uV (tested on AP) or less (up to 3A). Use best inductor and multiple C in parallel for low distortion . Use RDC snubbers on outputs to eliminate the oscillations. Design the PCB for low EMI. Why rely on feedback when you can design for ultralow distortion in the first place ?
Time will tell if we chose the right approach .
The numbers above are incorrect.
Purifi Amp has about 0.003 THD+N 20-20Khz 5W to 133W.
Bosc Gan , depends on what you see. As far as THD levels we beat them already (above numbers)
Our amp will be independently verified by Amir and I guarantee that our numbers willl be 2-3db better (since our AP floor is not as good)
At last , this is not about THD only. The SQ of a class d is not only AP numbers but multiple noise reduction techniques .
For those of you that know our TPA3118 design ,or for anyone else , you can check indepandant reviews and measuring on Amir site. We have reduced noise on output for example , something that's not taken into consideration on those forums.
Yes DrMordor design seems to be very competent , but experience in class D is crucial . Show me the noise on output , EMI levels , THD. Once you can tame those you can have a good sounding Class D design
As for us , we are still doing the incremental work on our AMP and when its ready we will have some units sent to test.
Yes you can use loop gain to reduce THD and the math makes perfect sense. However we approach this differently. Make a LLC quasi resonant, dual power with noise at 1uV (tested on AP) or less (up to 3A). Use best inductor and multiple C in parallel for low distortion . Use RDC snubbers on outputs to eliminate the oscillations. Design the PCB for low EMI. Why rely on feedback when you can design for ultralow distortion in the first place ?
Time will tell if we chose the right approach .
Looks good.
We are reaching 0.00013 and only H2 present (nothing else). You can see the FFT somewhere here.
There is some data that suggest that higher harmonics should be weighted differently as far as sound quality .
We are reaching 0.00013 and only H2 present (nothing else). You can see the FFT somewhere here.
There is some data that suggest that higher harmonics should be weighted differently as far as sound quality .
Hi amigos,
Got last TPA3255 by 3E Audio. (8 Ohms version with 44V PSU)
Here some pictures so you can have an idea about its size VS AIYIMA TPA3251 VS DrMordor TPA3255
I did not test it yet...
But at first sight + and - :
- Seems well made and solid, compact if you consider the integrated PSU ++
- Elna Audio Grade caps for buffer ++
- OP amps DIP8 Socket ++ (update OPA1602 in pictures with a copper film)
- Anti Pop protection ++
- Chengx Power caps -- (4x1000uf)
- Noiseless Fan +- (useful ?)
- CODA inductors (not sure about this, unmarked ?) --
- QC3008 Aptx BT chip ++
- No power cord provided --
- Quasi resonant PSU ++
Next step : Audio test VS DrMordor VS Aiyima A04 (Tilear Rev 2.1)
Got last TPA3255 by 3E Audio. (8 Ohms version with 44V PSU)
Here some pictures so you can have an idea about its size VS AIYIMA TPA3251 VS DrMordor TPA3255
I did not test it yet...
But at first sight + and - :
- Seems well made and solid, compact if you consider the integrated PSU ++
- Elna Audio Grade caps for buffer ++
- OP amps DIP8 Socket ++ (update OPA1602 in pictures with a copper film)
- Anti Pop protection ++
- Chengx Power caps -- (4x1000uf)
- Noiseless Fan +- (useful ?)
- CODA inductors (not sure about this, unmarked ?) --
- QC3008 Aptx BT chip ++
- No power cord provided --
- Quasi resonant PSU ++
Next step : Audio test VS DrMordor VS Aiyima A04 (Tilear Rev 2.1)
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The Mean Well unit is spec'ed for around 160mV ripple and a Connex SMPS is rated around 68mV ripple or so. Quite a margin, but I am wondering if the amp is fussy enough of the PSU to take this difference and present it as an audible effects. Your thoughts please.