3 audio is a member here...so contact him...on ebay you might get a 3e board about 80Euro
if you want tit cheaper by a YJ TPA3255 board.
for battery power i have no experience but it depends what is your target
1 long life of the battery..less power, economic but long time listening music
2 power, boom box, party machine...etc...
chris
if you want tit cheaper by a YJ TPA3255 board.
for battery power i have no experience but it depends what is your target
1 long life of the battery..less power, economic but long time listening music
2 power, boom box, party machine...etc...
chris
You can still order to Texas Instruments for a TPA3255.
I am using my EVM board with battery. I used to use a laboratory power supply and was able to understand "instatnt" power required, not so much. Then I switched to a battery, the one from an electric bike. It has 42V when full and is able to 10A continuous abn peak to 20A, so much more than I need in my everyday listening sessions.
Frankly speaking I was not able to hear any difference, it is just because the lab power supply has a bit noisy fan...
I can listen around 2 weeks of music between 2 charges. Batt is 36V 13Ah, chemistry is LiIon. Acid Lead batteries are less dangerous but with less instantaneous power.
And if you use your bike battery, it means you can do 2 trips with it : one bike trip and one musical trip.
I am using my EVM board with battery. I used to use a laboratory power supply and was able to understand "instatnt" power required, not so much. Then I switched to a battery, the one from an electric bike. It has 42V when full and is able to 10A continuous abn peak to 20A, so much more than I need in my everyday listening sessions.
Frankly speaking I was not able to hear any difference, it is just because the lab power supply has a bit noisy fan...
I can listen around 2 weeks of music between 2 charges. Batt is 36V 13Ah, chemistry is LiIon. Acid Lead batteries are less dangerous but with less instantaneous power.
And if you use your bike battery, it means you can do 2 trips with it : one bike trip and one musical trip.
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I use battery power on all my gear since over 10 years ago and I don't look Back. Even my LT3045 regulators are fed by SLA batteries. It boggles my mind how people spend lots of money on fancy transformers, caps, inductors ect. to build linear supplies that are almost as good as a 25 sqip SLA battery
If by any chance they beat a 7.2 Amp battery by this approach, you put another bat in parallel, to half the internal resistence and all is fine again.
I get as many batteries as I want for free since I service systems with back up power. They need to be swopped every 4 years so they got plenty of life left in them.
Cheers, Klaus
Does the board worked before modding?
now its more complicated to look for the correction.
future proposal:
modification step by step...
this is a cap..104 ....SMD 0603 size ---- brown cap capacity is 100nF
setup is in pF-> 10 +4 digit zeros = 100000 pF --> 100nF
resistor should have a number labeled - e.b. 4k7, 473, etc.
actually im in the office and my time is limited..this caps should be a filter cap for the output or input...i am not sure - i am not an expert at regulator .....look at the datasheet
check if the LM2575 has no shortcuts.
measure the input voltage and the output voltage if the regulator is still working.
chris
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Thankyou. Board worked before mod. though not played music
checked for any shorts/continuity before switch on. not checked output voltage. will check and try again after replacing the o.1uf cap.
in middle of moving house so not much time. thinking of just settling with a class AB board from a local manufacturer.
thankyou
I don’t have my stuff here to look at but lots of my friends and family and I use the MeanWell SE 600-48 PSU with the 3255. I use one of each per channel of my Linkwitz speakers for the sub drivers. Just for fun!
Our solution for the fan is to put a thermal switch inline with the fan leads. Get one “normally closed” and mount it on the heatsink. Careful though, it needs to be electrically isolated from the sink. Usually they come with a plastic sleeve for this. I think I have one from Amazon rated at 45deg Celsius, not sure, they come in various settings. In everyday use it never comes on if the PSU isn’t in an enclosed cabinet but you have the peace of mind that you are not cooking the PSU. If it does get hot then you have a noisy fan/alarm to warn you! Also if the amp is drawing that kind of power you probably won’t hear even a fan like that stock one, or maybe never hear anything again!
Other people use the quiet computer fans of larger diameter rigged to blow air through the hole where the noisy fan was. Or put it in a larger box and have the quiet fan blow into the box and the exhaust of the PSU up against an exit hole in the box. I prefer no sound to a quiet sound, so I use the switch.
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Variac, is it something like this (I stopped using the PS due to the fan noise)?
4 piece Thermal protection KSD9700 250V 5A 45 Degree NC 45C normally closed Thermostat Temperature Switch Bimetal Disc Control - - Amazon.com
4 piece Thermal protection KSD9700 250V 5A 45 Degree NC 45C normally closed Thermostat Temperature Switch Bimetal Disc Control - - Amazon.com
I have bought this unit:TPA3255 50V Banggood
Do they still come with the LM2575(T/S) power regulator limited to 40V despite being advertised as 50V? I have some 48V supplies that I would like to use.. Do people use it with 48V+ without getting broken units after a while?
If not overly concerned about the perfect sound, are there any other necessary mods that actually audibly enhance the sound?
Do they still come with the LM2575(T/S) power regulator limited to 40V despite being advertised as 50V? I have some 48V supplies that I would like to use.. Do people use it with 48V+ without getting broken units after a while?
If not overly concerned about the perfect sound, are there any other necessary mods that actually audibly enhance the sound?
Instead of $17 for 4 pcs
You can find these much cheaper: 3pcs for $1 @ ebay
// But these open the connection when the temp is reached.
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Hi
the regulator is according to doc a version which is not able to keep the technical specification of the S version- same chip- same production line....so it could be ok but without garantee. i would not do it.
try to adjust your power supply with the variable resistor on it.
for more mods read the thread:
https://www.diyaudio.com/forums/class-d/309813-wrong-tpa3255-30.html#post5499268
chris
It has been suggested to me that a zener diode mod in series with the LM2575 would drop the voltage to an acceptable range and still be able to supply the logic. What do you think of this mod?
if you "need" 48V as rail supply and waste heat on the zener....
i use my TPA3255 boards at 24V(cLass D BTL =48V ideal) or 36V if i have more space in the housing.
chris
Do you happen to know the power going to the logic? Is it that high?
Ideally i would like to have 48V to the rail. Most applications wont need this but I have one where Id like to power a dual voice coil subwoofer, here max power would be ideal.
hi
48V -40V = 8V with 150mA --> 1,2W heat
at post #548 we start discussing the power consumption..#589https://www.diyaudio.com/forums/class-d/309813-wrong-tpa3255-59.html#post5625711
Ok. Not too severe. If I were to replace the LM2575 with a LM2575HV, is it the fixed 12V or 15V output version (LM2575HVS-12/NOPB / LM2575HVS-15/NOPB) that should be used?
Thanks
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