Hi guys
just finished two board on 3255
pffb
Show your amp
The PCB's desined by Denz (me) 😉
OPamp - TI OPA1656 New Gen SoundPlus
DC/DC - TI LM5017
Power Inductors - Würth Elektronik
Power Cap - KEMET 13000h life
OPamp - TI OPA1656 New Gen SoundPlus
DC/DC - TI LM5017
Power Inductors - Würth Elektronik
Power Cap - KEMET 13000h life
Heatsink with fan?
my amp TPA3251 with PFFB
The PCB's desined by me, 2OZ CU
OPamp - TI OPA1652
DC/DC - TI LM5007, LM317 for gatedrive, 7A4700 for anlog section
Power Inductors - selfmade Epcos RM8 N87
Power Cap - Panasonic FC on amp board, FM on PSU board.
my amp TPA3251 with PFFB
The PCB's desined by me, 2OZ CU
OPamp - TI OPA1652
DC/DC - TI LM5007, LM317 for gatedrive, 7A4700 for anlog section
Power Inductors - selfmade Epcos RM8 N87
Power Cap - Panasonic FC on amp board, FM on PSU board.
Attachments
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For continuous load, yesHeatsink with fan?
good job, modular designmy amp
For continuous load, yes
good job, modular design
Thanks))) top PCB LLC PSU 33V 10A
Hi Denz82 & drMordor, Very nice boards indeed.
it is visible that these have been designed by electronics guys... well done gents! 🙂
it is visible that these have been designed by electronics guys... well done gents! 🙂
Hi Denz82 & drMordor, Very nice boards indeed.
it is visible that these have been designed by electronics guys... well done gents! 🙂
Thanks))))
After adjustion c_fb_out to 220pf everything works
Nice, how is your step response for square-wave now? Does it ring with open outputs?
Hello!
Always been a sucker for diy-projects. Have now stumbled into the diy audio world.
Started with a pair of amiga speakers by Paul Carmody and love them.
Next project is planned to be a amplifier with 2 mono tpa3255 by 3eaudio. I would like to build them in the same chassi with a shared power supply, i'm now trying to calculate what power supply i will need.
Could anyone point me in the direction of some instructions in how to calculate this.
Best regards Axel
Always been a sucker for diy-projects. Have now stumbled into the diy audio world.
Started with a pair of amiga speakers by Paul Carmody and love them.
Next project is planned to be a amplifier with 2 mono tpa3255 by 3eaudio. I would like to build them in the same chassi with a shared power supply, i'm now trying to calculate what power supply i will need.
Could anyone point me in the direction of some instructions in how to calculate this.
Best regards Axel
I got a first feedback from 3E Audio.
There are in the process of releasing two finished Amplifier based on TPA3250 and 3255 with a DSP inside.
TPA3250 – 2x100W (hummm TPA3251 would be a better choice...)
TPA3255 – 2x200W
Bluetooth 5.0 with Aptx
ADAU1701 DSP processing
LED Ring Volume Display
I wonder why they did not use a TAS3251 instead that integrates an internal DSP....
There are in the process of releasing two finished Amplifier based on TPA3250 and 3255 with a DSP inside.
TPA3250 – 2x100W (hummm TPA3251 would be a better choice...)
TPA3255 – 2x200W
Bluetooth 5.0 with Aptx
ADAU1701 DSP processing
LED Ring Volume Display

I wonder why they did not use a TAS3251 instead that integrates an internal DSP....
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I got a first feedback from 3E Audio.
T...
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I wonder why they did not use a TAS3251 instead that integrates an internal DSP....
To work with the TAS3251, I must recognize that the ADAU1701 DSP has a much more open configuration application, with Analog Device Sigma Studio.
Performance wise, I don't know how this DSP and the TAS3251 one compare.
JMF
I have been watching your post with interest as I have the same TPA3255 amplifier and also playing with Op-amps.
I think I have the same OPA1622 DIL units bought from china. No markings on the chip. How do I know if they are not fakes. ?? I couldn’t see any markings on your chips from the photos.
Many thanks. James. Devon. UK.
I think I have the same OPA1622 DIL units bought from china. No markings on the chip. How do I know if they are not fakes. ?? I couldn’t see any markings on your chips from the photos.
Many thanks. James. Devon. UK.
Time test )
I put the OPA1622 inside and testet with my hand mande linear PSU (40VDC)
I also connected my P1 Preamp with some Tung Sol US tubes....
It sounds just fantastic ! Lot of dynamics, sweet and absolutely noiseless.
I need to burn it a bit more... I am really happy for now.
The only issue is the lack of an Anti Pop circuit... IF SOMEONE CAN HELP TO AVOID THIS ?
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Yes, you DO know 😀!I think I have the same OPA1622 DIL units bought from china. No markings on the chip. How do I know if they are not fakes. ?? I couldn’t see any markings on your chips from the photos.
Best regards!
I am guessing the test being your ear !!
Having worked for Texas Instruments in the past - all the chips we used to ship were clearly marked but none of these OPA1622 chips coming out of China appear to have any markings at all. Even the NE5532P chips that ship with the amplifier are clearly marked.
Having worked for Texas Instruments in the past - all the chips we used to ship were clearly marked but none of these OPA1622 chips coming out of China appear to have any markings at all. Even the NE5532P chips that ship with the amplifier are clearly marked.
Yes, you DO know 😀!
Best regards!
I have been watching your post with interest as I have the same TPA3255 amplifier and also playing with Op-amps.
The genuine ones look like this :
You will here the difference easily compared to the NE5532.... if not : it could be a fake

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I need some help sorting out hum in my dual 3e tpa3255 build. Each card is a stereo board and I have connected same colors together on the dual inputs. Jumpers set to DIFF(right side). One board for left and one for right channel with biamping in stereo mode. Can this cause hum? I just hooked up a newly built a es90038 DAC in XLR mode and a PA amp so I'm not certain where the problem is. All have mutual ground through the XLR cables. None of the components have ground on the power side since I've built dac and tpa3255 amps double isolated to avoid hum problem.Each card have its own Mean Well psu. I've noticed the 3e board has ground on both left and right side inputs so I tried lifting one gnd cable to see if the small ground loop could be the issue. It did not help. With both signal ground lifted this amp got quiet but the PA amp started to hum! Any pointers to find out where the problem lies would greatly appreciated!
Attachments
Hello everyone, i am reading all your comments regarding the TPA3255 and i cannot decide between two models (one that has been reviewed already on the forum, and one that has Bluetooth as well).
Previously reviewed amp:
TPA3255 Power Amplifier 300Wx2 Class D Stereo Audio Amp HiFi 2.0 Digital Amplifier For Speaker Home Sound Theater DIY|Amplifier| | - AliExpress
Bluetooth model:
AIYIMA APTX Bluetooth 5.0 QCC3008 Amplificador Audio TPA3255 325Wx2 Class D Hifi Power Sound Speaker Amplifier HIY Home Theater|Amplifier| | - AliExpress
Both look like having Nichinon capacitors.
Do you think the Bluetooth model will have the audio quality degraded also on the RCA inputs? I see a relay there but there are no schematics.
What is your opinion?
Thanks in advance.
Previously reviewed amp:
TPA3255 Power Amplifier 300Wx2 Class D Stereo Audio Amp HiFi 2.0 Digital Amplifier For Speaker Home Sound Theater DIY|Amplifier| | - AliExpress
Bluetooth model:
AIYIMA APTX Bluetooth 5.0 QCC3008 Amplificador Audio TPA3255 325Wx2 Class D Hifi Power Sound Speaker Amplifier HIY Home Theater|Amplifier| | - AliExpress
Both look like having Nichinon capacitors.
Do you think the Bluetooth model will have the audio quality degraded also on the RCA inputs? I see a relay there but there are no schematics.
What is your opinion?
Thanks in advance.
Hello everyone, i am reading all your comments regarding the TPA3255 and i cannot decide between two models (one that has been reviewed already on the forum, and one that has Bluetooth as well).
Both look like having Nichinon capacitors.
Do you think the Bluetooth model will have the audio quality degraded also on the RCA inputs? I see a relay there but there are no schematics.
What is your opinion?
Thanks in advance.
I will go for the AIYIMA TPA3251 instead with Antipop at Startup (see my previous coments) it uses ELNA audio grade caps as well.
To answer you both are the same, the second TPA3255 has just a QC3008 BT APTX chip added.
I have absolutely no complains with the RCA inputs (I use a DAC double AK4497 with BT APTX HD protocol). You can improve the sound when changing the AOP (OPA1622 for example)
For the PSU this one just works fine with the TPA3251 :
FX-AUDIO Adaptateur Secteur Alimentation 100-240V vers 36V 6A - Audiophonics
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