TPA3255 - all about DIY, Discussion, Design etc

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#4,962
Appreciate a bit of insights into connecting a VU Meter to the TPA 3255. The setup is a TPA 3255 powered by a Meanwell SMPS 48V.
I need to connect a VU meter to this setup. I am using another 12V SMPS to power up the driver board and the backlight of the VU Meter. The problem is how do i connect the audio ground ? The dotted line in the diagram below is what is bothering me. I am not sure, if i can connect the 2 grounds of SMPS
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#4,963
depending on the sensitivity of the VU meter, you can connect them at the input of the amplifier or after the volume control, providing your input is not balanced. You can connect them to one side of the output and ground. Use a coupling cap and resistor dividers when connection to the VU meters.
 
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#4,964
Karlsonate said:
In that case, your next best option is a Meanwell SMPS.
You should check their datasheets for ones with low ripple and go from there.
There's this Connex one too: CONNEX SMPS300RE Switched-Mode Power Supply Module US Version 300W +/-24V 120V - Audiophonics
Click to expand...
I don't wanna pay that much and i need one that is 220 volt and plug and play

Audiophonics have this one but i don't know if the quality is good https://www.audiophonics.fr/en/powe...adapter-100-240vac-to-42v-dc-85a-p-17308.html
 
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#4,965
multisync said:
depending on the sensitivity of the VU meter, you can connect them at the input of the amplifier or after the volume control, providing your input is not balanced. You can connect them to one side of the output and ground. Use a coupling cap and resistor dividers when connection to the VU meters.
Click to expand...


Thanks for a response multisync. The problem is with the ground line(the dotted line in the diagram). I am not very sure that i can connect the ground lines of 2 different SMPS powered by the same source. In this case, i would be connecting the 48V SMPS ground line to the 12V SMPS ground line, is that ok?
 
#4,969
If you are worried about SMPS noise, use linear power supplies. Then again there are many post here about 60 Hz or 120 Hz noise from ground loops. Search "gain structure" on this or other forums. I have made several tpa3116, tpa3255 amplifiers as well as others. Don't sweat the small details. There are thousands of different brands and builds of amplifiers. Most of the good ones are hard to tell apart by most people in double blind tests.
 
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#4,972
maybe 10 Ohm not 10,000 Ohms. You will need some type of divider at the input to your Vu meters. I think they might hit full scale long before the music gets loud. I bought 48 led Vu meters, actually 48 led display and they hit full scale with less than 1 volt RMS input. The bottom 4 leds would come on at the same time as well as the top 4 leds. Dynamic range for the 48 led meter was 24 db. They were cheap.
 
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#4,973
I haven't read to this thread for a while. In the meantime my DIY 3e-audio TPA3255 amp died (I already got a new smps), but also my wife demanded downsizing an AVR that served as a preamp (the old Rotel is a real brick). So I searched for an AV preamp and found just two options: Canton Smart Connect and Nubert nuXinema preAV. I also looked at d-class avrs with a though of connecting to pre-outs but no luck (seems like these are not so popular anymore as probably soundbars canibalised their niche) but found a HEOS 5.1 AVR on sale. I looked for a service manual and found out it has 3 TPA3251D2 on board.

Can someone have a look at service manual, if that thing is worth anything? It looks like it has seprate power lines for the AMPs (8.5amp 34V), digital and pre.
It has two DACs: PCM5100 (for Stereo?) and PCM1690 for 5.1. Volume and tone is done on BD3473KS2.

https://www.manualslib.com/manual/2936255/Denon-Heos-Avr.html

what do you think? It can be grabbed at really good prices second hand too.
 
#4,974
seez said:
I haven't read to this thread for a while. In the meantime my DIY 3e-audio TPA3255 amp died (I already got a new smps), but also my wife demanded downsizing an AVR that served as a preamp (the old Rotel is a real brick). So I searched for an AV preamp and found just two options: Canton Smart Connect and Nubert nuXinema preAV. I also looked at d-class avrs with a though of connecting to pre-outs but no luck (seems like these are not so popular anymore as probably soundbars canibalised their niche) but found a HEOS 5.1 AVR on sale. I looked for a service manual and found out it has 3 TPA3251D2 on board.

Can someone have a look at service manual, if that thing is worth anything? It looks like it has seprate power lines for the AMPs (8.5amp 34V), digital and pre.
It has two DACs: PCM5100 (for Stereo?) and PCM1690 for 5.1. Volume and tone is done on BD3473KS2.

https://www.manualslib.com/manual/2936255/Denon-Heos-Avr.html

what do you think? It can be grabbed at really good prices second hand too.
Click to expand...
I bought one for 380 euros used in new condition.... I love the design! The AVR processors are too expensive... This one seems to be a good compromise with 3 TPA inside!
I can't wait to receive it and of course try it. 😉👍
 
#4,980
@mamocel did you receive yours? I got mine (new one from distributor). The wifi setup didn't work via WPS but after initial setup with cable and manually entering wifi settings it worked. Judging by the ear, it has similar sound signature to my old DIY TPA3255 amp. It is transparent, detailed and dynamic, I quite like it. The design is indeed great. I like the minimalist look of it, It looks like a stereo amplifier without tone control, just the volume. Running it in direct mode it does redirect bass to LFE output (it may do AD-DA for the low end but pass through the full range directly to the amp and front speakers). So far I like it.
 
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