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Deleted member 148505
On loud room music listening, it's very easy to clip the amp when a 24V supply is used specially on low sensitivity speakers.
If THD+N is your concern, best compromise would be around 36V to 38V, or maybe up to 43V.
Based on my tests, my module is losing 2dB to 3dB THD+N at 5W 4ohms 1kHz (mostly +N part), if I increase the supply voltage to 51V as compared to when using a 38V DC supply.
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I built a linear supply from bits taken from dormant amps which gives 42vdc there is nothing wrong with the sound but I find that using the 24vdc supply gives the same volume and is more refined probably due to the better filtering and regulation given by the Teddy Pardo regulators,
Puffin,
Would you be so kind as to open it up and take a few pictures of its internals? AFAIK, it's one of the cheapest ready-to-go TPA3255 amps out there, with (supposedly) DSP capabilities thrown in for good measure 🙂
Based on my knowledge of amplifiers using similar chipset, many people reported that upgrading to a 48V (Meanwell) SMPS is a bit overkill, and there's no noticeable change in SQ compared to say a common 32V brick charger. Cleaner power certainly won't hurt.
K.
@Karlsonate. I have had many Class D amps, most of which were boards that I modified as a result of the numerous threads on here. Some chips (the TA2024 in particular} would blow if you so much as looked at them in the wrong way! I would be unhappy to open it up just in case I look at it in the wrong way.....if you know what I mean. Unless and until there is a thread on here regarding upgrades or tweaks that could be done to it, it will remain intact.
Best Wishes Puffin.
Best Wishes Puffin.
Not sure if this is the best place to post this but guessing so.
Really enjoying having my D200 back in the system. Recently I acquired XRKs diamond buffer (unity gain).
Not expecting to be able to better Lesters design at all, but this being DIY and we like to try different things, I was wondering about using the diamond buffer in place of the opamps on the D200. The diamond buggers are SE. Is this feasible/ worth bothering with?
Thanks
Really enjoying having my D200 back in the system. Recently I acquired XRKs diamond buffer (unity gain).
Not expecting to be able to better Lesters design at all, but this being DIY and we like to try different things, I was wondering about using the diamond buffer in place of the opamps on the D200. The diamond buggers are SE. Is this feasible/ worth bothering with?
Thanks
Hi Jim,
D200 is configured as BTL with differential inputs.
You need a balanced driver if you want to bypass the preamp, also, you need to run the amp in non-pffb mode if you were to bypass it.
Remove the opamps and connect the balanced driver to pins 1 (hot) and 7 (cold) of the opamp socket.
Regards,
Lester
Gain of TPA3255 is fixed regardless of the PVDD supply voltage, so yes, it should have the same volume all throughout the supply range if early clipping is not of your concern.
Hello,
Today I turned on my D400m amplifier and one of the two boards lights up the CLIP_OTW LED. I tried disconnecting both inputs and outputs but the problem persists. What could have happened?
I have tryed tu short mute pin and clip_otw led turn off.
These tests were also done with the operational amplifier disconnected.
Any suggestion?
Today I turned on my D400m amplifier and one of the two boards lights up the CLIP_OTW LED. I tried disconnecting both inputs and outputs but the problem persists. What could have happened?
I have tryed tu short mute pin and clip_otw led turn off.
These tests were also done with the operational amplifier disconnected.
Any suggestion?
Hi Vito,
If the CLIP_OTW LED lights up immediately after booting up, and the light is bright and steady, then there's a problem with the PFFB configuration. If the jumpers for PFFB is connected, it needs a buffer to work correctly, so it will not work with opamp disconnected.
However, if your amp boots up, and after a while the CLIP_OTW lights up, it means that the overtemperature warning LED has turned on.
If the CLIP_OTW is pulsing erratically, then there's a ground loop or a wiring problem with the setup.
If both CLIP_OTW and FAULT red LEDs turned-on, it means the IC is damaged and requires replacement.
Regards,
Lester
If the CLIP_OTW LED lights up immediately after booting up, and the light is bright and steady, then there's a problem with the PFFB configuration. If the jumpers for PFFB is connected, it needs a buffer to work correctly, so it will not work with opamp disconnected.
However, if your amp boots up, and after a while the CLIP_OTW lights up, it means that the overtemperature warning LED has turned on.
If the CLIP_OTW is pulsing erratically, then there's a ground loop or a wiring problem with the setup.
If both CLIP_OTW and FAULT red LEDs turned-on, it means the IC is damaged and requires replacement.
Regards,
Lester
Hi hannemam, I see you used the Eizz pot. I'm a DIY beginner and I'm stuck in my first ampli project using a 3e-Audio 260-2-29A and an Eizz 100k stereo pot wich is giving me troubles for it doesn't regulate the volume as expected: it keeps the output low for most of the swipe then it goes to max with the last two steps. Replacing the Eizz with a cheap 100k linear pot the problem is gone. Do you have any clue?
Hi hannemam, I see you used the Eizz pot. I'm a DIY beginner and I'm stuck in my first ampli project using a 3e-Audio 260-2-29A and an Eizz 100k stereo pot wich is giving me troubles for it doesn't regulate the volume as expected: it keeps the output low for most of the swipe then it goes to max with the last two steps. Replacing the Eizz with a cheap 100k linear pot the problem is gone. Do you have any clue?
Hello @SylphAudio,
I'm a little disappointed by the very late replies. Ultimately not receiving more information, I replaced the TPA3255 chip. The result is that there is no more DC offset and the CLIP_OTW led is off. But now when I connect a source there is a noise like that of ground loops. But I can guarantee that there is no ground loop as the other identical amp (i own 2 x D400) works fine in the same situation. My question is whether there is technical support for these amplifiers after purchase? Can you help me to find issue?
Thanks
I'm a little disappointed by the very late replies. Ultimately not receiving more information, I replaced the TPA3255 chip. The result is that there is no more DC offset and the CLIP_OTW led is off. But now when I connect a source there is a noise like that of ground loops. But I can guarantee that there is no ground loop as the other identical amp (i own 2 x D400) works fine in the same situation. My question is whether there is technical support for these amplifiers after purchase? Can you help me to find issue?
Thanks