3e-has a 200 watt 36 volt SMPS, it will serve a 2x200 watt rms amp very well, as you do not play sine waves, but music. SMPS power does not equal amp power. For short bursts of high energy, the amp uses the capacitor reservoir, while the SMPS fills them permanently. If the SMPS is high quality, 200 watt continious power is more than many well sized AVR´s have. You would be surprised how "weak" the power supply´s of many high power HIFI amps are.
Most of the cheaper Aliexpress SMPS will work, but their output is overrated. So better get a 300 watt version, if you want to use 150 watt. There are too many of them to give a definite recommendation. Also, some are slow and better suited for LED´s, some are reported to sound bad on amps. Maybe read a bit, there are quite some strong ones, like 600 watt around, not very expensive and well build. I can not advise on them, as I have no personal experience.
If you want a very good amp without experimenting, stick to stuff out of one hand that is designed to work together.
Many here have piled up huge stocks of electronics stuff that did not work as thought.
Also, many opinions here are subjective, the noise of an amp that some find OK may make it a "no-no" for another person.
You will have to design a bit of your own anyway, for example, the 3e-audio amps can be used with symmetric inputs if you want. So there is quite something to learn if you are no electronics pro.
Most of the cheaper Aliexpress SMPS will work, but their output is overrated. So better get a 300 watt version, if you want to use 150 watt. There are too many of them to give a definite recommendation. Also, some are slow and better suited for LED´s, some are reported to sound bad on amps. Maybe read a bit, there are quite some strong ones, like 600 watt around, not very expensive and well build. I can not advise on them, as I have no personal experience.
If you want a very good amp without experimenting, stick to stuff out of one hand that is designed to work together.
Many here have piled up huge stocks of electronics stuff that did not work as thought.
Also, many opinions here are subjective, the noise of an amp that some find OK may make it a "no-no" for another person.
You will have to design a bit of your own anyway, for example, the 3e-audio amps can be used with symmetric inputs if you want. So there is quite something to learn if you are no electronics pro.
Last edited:
Hi all,
I’m very new to DIY audio and wanted to build my first DIY amp to power some KEF LS50’s. Would the Meanwell Hep-600-48 be overkill for such an application and would a more cost effective SMPS be the LRS-350-48?
TI use the HEP 600 at their demos apparently, but it’s pricey. I wouldn’t mind building something with some headroom anyway in case I wanted to repurpose it for another project, but wanted to check whether this was an unnecessary purchase.
Any thoughts greatly appreciated.
I’m very new to DIY audio and wanted to build my first DIY amp to power some KEF LS50’s. Would the Meanwell Hep-600-48 be overkill for such an application and would a more cost effective SMPS be the LRS-350-48?
TI use the HEP 600 at their demos apparently, but it’s pricey. I wouldn’t mind building something with some headroom anyway in case I wanted to repurpose it for another project, but wanted to check whether this was an unnecessary purchase.
Any thoughts greatly appreciated.
See, if you had an A/B amp with 60% eff. and a unregulated transformer power supply, one could see sense in 600 watt, to keep voltage constant at any level.
Here you have a 90% eff. D-amp, with a regulated SMPS that keeps 36 volt constant, even at peak´s much higher than the nominal output of 200 watt (if we refer to the 3e-audio SMPS). So even under high load, the voltage will be keept at 36V.
The KEF LS50 will just burn out, after a few seconds of a 100 watt sine wave, even if it can handle short peaks that are much higher. So both, the 200W and 600W SMPS will keep the voltage at constant 36V. Where do you see an advantage?
If you are a High Ender, you might feel better with a 3 times over dimensioned power supply, but the sound will be 100% the same.
If you prefer to drive the amp with 48 volt, the 3e-audio is out anyway.
Instead of buying an expensive, slow LED supply, I would consider to go dual mono, with two TPA3255 1CH and two separate PS like the SMPS300R 48V 300W Switching Power Supply from Connexelectronic, which has a peak of 400watt and is well suited for audio.
Will be a better amp for less money...
Here you have a 90% eff. D-amp, with a regulated SMPS that keeps 36 volt constant, even at peak´s much higher than the nominal output of 200 watt (if we refer to the 3e-audio SMPS). So even under high load, the voltage will be keept at 36V.
The KEF LS50 will just burn out, after a few seconds of a 100 watt sine wave, even if it can handle short peaks that are much higher. So both, the 200W and 600W SMPS will keep the voltage at constant 36V. Where do you see an advantage?
If you are a High Ender, you might feel better with a 3 times over dimensioned power supply, but the sound will be 100% the same.
If you prefer to drive the amp with 48 volt, the 3e-audio is out anyway.
Instead of buying an expensive, slow LED supply, I would consider to go dual mono, with two TPA3255 1CH and two separate PS like the SMPS300R 48V 300W Switching Power Supply from Connexelectronic, which has a peak of 400watt and is well suited for audio.
Will be a better amp for less money...
Last edited:
TPA3255EVM BTL or PBTL?
I presently am running two woofers, each driven separately by each of the two channels in BTL mode but am wondering if I parallel the woofers and run TPA3255EVM in PBTL mode will the maximum voltage difference across the outputs be double vs BTL mode? I thought I original understood this but the more I think about it I am not certain. Any thoughts appreciated!
I presently am running two woofers, each driven separately by each of the two channels in BTL mode but am wondering if I parallel the woofers and run TPA3255EVM in PBTL mode will the maximum voltage difference across the outputs be double vs BTL mode? I thought I original understood this but the more I think about it I am not certain. Any thoughts appreciated!
Attachments
Last edited:
As you have only half the impedance in parallel, you keep the voltage and double the current. So, VxA=W you have twice the power. PBTL is only a way to double the possible current of an amplifier, so PBTL only gives more power with lower load resistor.
That is what in your case happens.
Downside of this is the halved damping factor of the amp with lower impedance.
So in theory control of the sub will be worse. If this is audible depends on your installation, how the sub is tuned and the amp.
In practice I had very different and sometimes not logical subjective impressions with this.
So maybe try it and listen. If your sub´s needed more power, the sound should improve, if not and they need a lot of damping at the resonance frequency, it may suffer.
That is what in your case happens.
Downside of this is the halved damping factor of the amp with lower impedance.
So in theory control of the sub will be worse. If this is audible depends on your installation, how the sub is tuned and the amp.
In practice I had very different and sometimes not logical subjective impressions with this.
So maybe try it and listen. If your sub´s needed more power, the sound should improve, if not and they need a lot of damping at the resonance frequency, it may suffer.
Thanks for your reply Turbowatch, you’ve certainly given me more to think about. Cost wise however it seems the solution you propose would be more expensive than my initial plan, however if it means the speakers won’t be damaged and the sound will be better then that would be great. Plus I think an off-the-shelf solution would cost much more and making things is far more rewarding anyway.
It seems that TI use the HEP-600-48 when running the TPA3255 in PBTL mode which of course isn’t relevant to my use. I should have researched more so my apologies.
Don´t get me wrong.
The Mean Well HEP-600-48 sure works well for the TPA3255, but it is self contained, more a lab supply and very expensive. As you need some kind of case for the amp anyway, I see no advantage in using it, while you get the same power from a 70$ supply that has been used in audio without problems for many times
As far as I have calculated, two 3e-audo mono amps with two 600W each would come to about the same amount of money as a single Mean Well HEP-600-48.
Doesnt make sense to me.
The Mean Well HEP-600-48 sure works well for the TPA3255, but it is self contained, more a lab supply and very expensive. As you need some kind of case for the amp anyway, I see no advantage in using it, while you get the same power from a 70$ supply that has been used in audio without problems for many times
As far as I have calculated, two 3e-audo mono amps with two 600W each would come to about the same amount of money as a single Mean Well HEP-600-48.
Doesnt make sense to me.
Irauadamp7s vs tpa3255
Hi.I already have Iraudamp7s in bridge mode 500w to feed SB34NRX75-6 woofer with LCC Ps at 48v.I will make a stereo sub so i bought one more piece of same woofer.It will arrive in a month.Do you think Tpa3255 ready amps on Aliexpress will be an upgrade?.I am curious because it writes pure hd on datasheet.Thanks and best regards Ümit
Hi.I already have Iraudamp7s in bridge mode 500w to feed SB34NRX75-6 woofer with LCC Ps at 48v.I will make a stereo sub so i bought one more piece of same woofer.It will arrive in a month.Do you think Tpa3255 ready amps on Aliexpress will be an upgrade?.I am curious because it writes pure hd on datasheet.Thanks and best regards Ümit
My tests w Connexelectronic 800w 48V for $150 (not free shipping), was surprisingly noisy ( could hear awful hiss), whereas $44 (shipping included) LED SMPS 1200w 48v was absolutely silent. FFTs support this observation.
TPA3255 Reference Design Class D Amp GB
A linear trafo and bridge and cap PSU is not quieter - hum vs hiss.
Last edited:
With the correct current limiting resistor in place, I was easily able to hit 28.27Vrms (200wrms) into 4ohms. You can see one of the power resistors with a local hot spot (left one near end). Will have to avoid these types of load resistors in the future. Only good as heaters as they add a lot of distortion to the measurement and may have unpredictable resistance.
The $44 SMPS 48v 800w (correction from above) did not break a sweat with the fan disconnected on the PSU.
The $44 SMPS 48v 800w (correction from above) did not break a sweat with the fan disconnected on the PSU.
Attachments
Last edited:
This makes it complicated to give any hint`s for others. You never know what exactly you get next week. Connexelectronic had quite a reputation to work well, but there is no guaranty for two times the same product.
Personally I stick with stuff that is sold in high amounts for quite some times with good or no negative comments, as cheap as I can buy. Aliexpress etc. It takes quite some time to arrive and sometimes it is crap. That is my risk.
I did not use LED SMPS, as they usually are more expensive. Someone told me they where a bit slow in reaction to changing load and have a worse overload caracteristic than others, which are designed for changing load, like CNC motors for example.
In the end it is what you have on your table.
If you need a huge load resistor, make an array out of large (surplus?) resistors and solder them together. If you drop them into a bucket of cold water for the measurement, they will work at many times the load as air cooled. I saw that in some east European video clip... primitive but clever.
Personally I stick with stuff that is sold in high amounts for quite some times with good or no negative comments, as cheap as I can buy. Aliexpress etc. It takes quite some time to arrive and sometimes it is crap. That is my risk.
I did not use LED SMPS, as they usually are more expensive. Someone told me they where a bit slow in reaction to changing load and have a worse overload caracteristic than others, which are designed for changing load, like CNC motors for example.
In the end it is what you have on your table.
If you need a huge load resistor, make an array out of large (surplus?) resistors and solder them together. If you drop them into a bucket of cold water for the measurement, they will work at many times the load as air cooled. I saw that in some east European video clip... primitive but clever.
Reminds me of my first BJT amp with 2n3055 and 2Ohms load in a bucket of water. This worked for about an hour, the water getting hotter and hotter. But then a loud bang! - and the output coupling cap exploded. A plethora of tiny snippeds spread around my room
