Is the sound , as it is right now, better with this board than with my Aiyima a04 with tpa 3251 ?
Yes it is - I think its the lack of the analog volumecontrol and the better output coils on this board that makes it sound slightly more effortless .
That said, the modded Aiyima a04 is better than many class A/B aamplifiers up to about 600 dollars.
Yes it is - I think its the lack of the analog volumecontrol and the better output coils on this board that makes it sound slightly more effortless .
That said, the modded Aiyima a04 is better than many class A/B aamplifiers up to about 600 dollars.
My power supply is external without earth wire.
It’s like a class II device .
Different opinions on this , but I have to ask :
Shall I ground the rca ground connector to the box , and is it maybe a good thing using a 10 ohm resistor between rca ground and box?
As it is now , the box is floating with no ground to rca that are entirely isolated with spacers . No hum, no noise , sound good .
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Still you can try out. There are no class II DIY devices anyway 😉 So just the box. Experiment of a few minutes.
Yes RCA isolated from box. If you connect the box via 10 Ohm to GND you’ll have a nice antenna.
Yes RCA isolated from box. If you connect the box via 10 Ohm to GND you’ll have a nice antenna.
Is the board technically grounded to chassis through the fasteners?
^^what jean-paul said^^
When I was initially planning the A07 build, I intended on adding a base heat-sink plate to the bottom, but was not 100% sure of any grounding issues, so I just mounted the case vertically for air flow. I updated the drawing for your 3255 board as I can pick up one of these and experiment too....
When I was initially planning the A07 build, I intended on adding a base heat-sink plate to the bottom, but was not 100% sure of any grounding issues, so I just mounted the case vertically for air flow. I updated the drawing for your 3255 board as I can pick up one of these and experiment too....
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Are you changing all the electrolytic capacitors when finalized? Maybe you can start a component part #'s list when you are done so others may follow suit.
I may do that , or I just settle with the output caps and all the low level coupling caps using Wima
The sound is now better than my audio phonics hypex ncore 125 in all parameters ( subjective )
The sound is now better than my audio phonics hypex ncore 125 in all parameters ( subjective )
4 Wima 4,7uF and 4 capacitors 1 uF on their way , arriving on friday.
With this board, theres no need to use any muting circuit even if the option is there. One can just cut the power at the AC side of the power brick. Theres no loud popping sound at turn on/off. However, if I would use this card in an active speaker driving tweeters, I would use a protection 20 uF cap as safety ( as always )
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Interesting thread.
I keep wondering how this thing would perform with an audio-grade PSU... 😊
Are you able to add an updated schematic to the thread, so we can see how this thing works?
I keep wondering how this thing would perform with an audio-grade PSU... 😊
Are you able to add an updated schematic to the thread, so we can see how this thing works?
Updated schematic? It is a ready made module put in a casing.
The standard thing is to try out a good linear PSU with class D amplifiers. Tombo56 designed a nice PSU but it can be done various ways. Thing is to make it LDO to avoid heat. Many say it is not a good idea as many a class D amplifier itself pollutes its supply lines. Try it out and experience the difference. It needs a larger casing for that though at least when one desires not to have an impractical external PSU. Either an R-core or toroid transformer and an LDO regulator at the desired voltage. Choose the right voltage and power rating (x2) for the transformer.
Point being that the higher the output power of the chosen amplifier the more difficult/expensive/large a linear PSU will become. It will also dissipate power converted to heat. The always occurring losses will start to count a lot. Simple. IMHO it will be practically impossible to do so for a 2 x 300W module. So for very high power it will definitely be a SMPS.
There is much beauty in low power 🙂
The standard thing is to try out a good linear PSU with class D amplifiers. Tombo56 designed a nice PSU but it can be done various ways. Thing is to make it LDO to avoid heat. Many say it is not a good idea as many a class D amplifier itself pollutes its supply lines. Try it out and experience the difference. It needs a larger casing for that though at least when one desires not to have an impractical external PSU. Either an R-core or toroid transformer and an LDO regulator at the desired voltage. Choose the right voltage and power rating (x2) for the transformer.
Point being that the higher the output power of the chosen amplifier the more difficult/expensive/large a linear PSU will become. It will also dissipate power converted to heat. The always occurring losses will start to count a lot. Simple. IMHO it will be practically impossible to do so for a 2 x 300W module. So for very high power it will definitely be a SMPS.
There is much beauty in low power 🙂
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Its an already made amplifier board put in a casing , but modified with better op amps and coupling capacitors .
As Audiogue on the forum has measured , the lowest distortion and possible best sound with the tpa3255 chip with 4 ohm load is feeding it with 34V . I use a 36V 6A power brick , so pretty near 🙂
People everywhere seems to use 48V , probably to max the output at 8 ohms with slightly higher distortion and with less capacity at 4 ohms.
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Who is Audiogue? The god of class D? Pretty near is not pretty the same and just 6A is a bit meagre certainly when using it with 4 Ohm loudspeakers. Probably both amplifiers are also not 100% the same (anymore). Possibly the results are different with a true clean ultra low output impedance (over a wide range) PSU and then we have the ear/measurements debate. It really is hard to compare stuff if the 2 samples are not in front of you on your desk 🙂
Anyway one does not need to be a guru to know film caps usually perform better for coupling and better coils/output filters combined with better ultra low noise PSUs with abundance of current do a good job in about any class D amplifier.
Anyway one does not need to be a guru to know film caps usually perform better for coupling and better coils/output filters combined with better ultra low noise PSUs with abundance of current do a good job in about any class D amplifier.
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He has this board and was active on this forum before , he has measured the output coils that turned out to be really good .
I get that this is a pre-built module, I just thought there might be a schematic flying around somewhere, so we could see what was going on...
There usually is.
This is helpful. 😉👍
There usually is.
This is helpful. 😉👍
The onboard regulator does not seem too fond of 48V.
I wonder why they put electrolytic caps in series for decoupling. One rarely sees this. The board is now sold for 17 Euro so one maybe should not expect too much.
I wonder why they put electrolytic caps in series for decoupling. One rarely sees this. The board is now sold for 17 Euro so one maybe should not expect too much.
Cost cuts , or better sound ? ( the resistance is higher because of that ) - but you do get good parallelled output coils ( lower resistance ) and the tpa3255 chip. Youre right about the regulator , I would not use more than 42 V.
Its the same with the very good sounding Shui Yuan Audio board.
And then theres the reliability - who knows
Its the same with the very good sounding Shui Yuan Audio board.
And then theres the reliability - who knows
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