Thanks FauxFrench for the useful advice, i think this is a very good candidate for this use 
I was thinking of going low-W tube amp and using an inverter, but i do like the simplicity of this solution 
I have built a few TPA3251s and own some of ebay FX-audio 3250 amps also. They are amazing value, and i cant imagine i would be disappointed with this one either.
I was thinking of going low-W tube amp and using an inverter, but i do like the simplicity of this solution I have built a few TPA3251s and own some of ebay FX-audio 3250 amps also. They are amazing value, and i cant imagine i would be disappointed with this one either.To start with the conclusion – this board is not particularly suited for DIY.
For long I was fighting with a considerable “click” when turning power ON. Only after hours of experiments, I realized that it was one of the SMD micro-transistors that was not well aligned on the PCB and at least one of the pins did not have connection with the corresponding PCB track. With strong reading glasses and the finest soldering tip, I managed to re-solder all transistor pins. Before that, the /RESET and /CMUTE pins were pulled up simultaneously and that caused the “click”. After repair, the /CMUTE pin was pulled high sometime after the /RESET pin. After repair, there was almost no start-up noise.
As I belived the “click” to be caused by poor initial design of the start-up circuit, I implemented my own circuit that starts up above 18.5V supply voltage for the board. Mine worked but the initial circuit may have worked as well, had I found the transistor problem that early.
The board uses SMD components to a large extent. The SMD components used are generally very small and the PBC tracks very fine with only a narrow trench separating a track from the ground plane. Being an economical solution, both analog and digital circuit parts are supplied from the same ordinary 78M05 voltage regulator. Splitting the analog supply pin from digital supply pins was very difficult and required very fine wire.
The board has many good intentions at a reasonable price. The TPA3221 IC, the Nichicon power rail decoupling capacitors, the output filter components, the film capacitors at the input, the heatsink etc. are of good quality. I managed with patience and very fine “wire-wrap”-wire to separate AVDD, GVDD and VDD into three different 5V supplies with better performance than the initial 78M05.
Test was with my homemade ES9023 DAC implemented with double regulated +/-3.5V supply. To my standards, the TPA3221 board sounded really good. The TPA3221 chip is of high quality but the board needs a more DIY friendly layout (size of components and PCB tracks) to be a success for DIY activities.
I have appended schematics for my version of a start-up circuit and my voltage regulator circuits, and a photo of the modified board. I used a 15V LM317 pre-regulator such that I had 15V available should I wish to add input buffer circuits. For that I had foreseen to use OPA1612. In the end I skipped such input buffers.
Use of a 8-pin micro-controller, such as the ATTINY 85 or similar, is a very good idea in general. For this particular board it is not easy because the 8-pin IC to be replaced has different power pin layout.
For long I was fighting with a considerable “click” when turning power ON. Only after hours of experiments, I realized that it was one of the SMD micro-transistors that was not well aligned on the PCB and at least one of the pins did not have connection with the corresponding PCB track. With strong reading glasses and the finest soldering tip, I managed to re-solder all transistor pins. Before that, the /RESET and /CMUTE pins were pulled up simultaneously and that caused the “click”. After repair, the /CMUTE pin was pulled high sometime after the /RESET pin. After repair, there was almost no start-up noise.
As I belived the “click” to be caused by poor initial design of the start-up circuit, I implemented my own circuit that starts up above 18.5V supply voltage for the board. Mine worked but the initial circuit may have worked as well, had I found the transistor problem that early.
The board uses SMD components to a large extent. The SMD components used are generally very small and the PBC tracks very fine with only a narrow trench separating a track from the ground plane. Being an economical solution, both analog and digital circuit parts are supplied from the same ordinary 78M05 voltage regulator. Splitting the analog supply pin from digital supply pins was very difficult and required very fine wire.
The board has many good intentions at a reasonable price. The TPA3221 IC, the Nichicon power rail decoupling capacitors, the output filter components, the film capacitors at the input, the heatsink etc. are of good quality. I managed with patience and very fine “wire-wrap”-wire to separate AVDD, GVDD and VDD into three different 5V supplies with better performance than the initial 78M05.
Test was with my homemade ES9023 DAC implemented with double regulated +/-3.5V supply. To my standards, the TPA3221 board sounded really good. The TPA3221 chip is of high quality but the board needs a more DIY friendly layout (size of components and PCB tracks) to be a success for DIY activities.
I have appended schematics for my version of a start-up circuit and my voltage regulator circuits, and a photo of the modified board. I used a 15V LM317 pre-regulator such that I had 15V available should I wish to add input buffer circuits. For that I had foreseen to use OPA1612. In the end I skipped such input buffers.
Use of a 8-pin micro-controller, such as the ATTINY 85 or similar, is a very good idea in general. For this particular board it is not easy because the 8-pin IC to be replaced has different power pin layout.
Attachments
Hi, here is a new TPA3221 "shui yuan" :
shui yuan Audio TPA3221 Digital Cl D Power Amplifier Board Module 100W + 100W High Power Amplifier|Amplifier| - AliExpress
That is the little brother of the shui yuan TPA3255 already described on this forum.
shui yuan Audio TPA3221 Digital Cl D Power Amplifier Board Module 100W + 100W High Power Amplifier|Amplifier| - AliExpress
That is the little brother of the shui yuan TPA3255 already described on this forum.
A different, and more expensive, TPA3221 board from "GHX" -
TPA3221 Stereo Digital Power Bluetooth 5.0 Amplifier Board 2*100W QCC3008 HiFi Audio Amplifier For Portable Speakers Diy|Amplifier| - AliExpress
And a fully cased dual TPA3221 -
HIFI Dual TPA3221 Digital Power Amplifier Board 2*120W Class D Stereo Audio Amplifier|Amplifier| - AliExpress
TPA3221 Stereo Digital Power Bluetooth 5.0 Amplifier Board 2*100W QCC3008 HiFi Audio Amplifier For Portable Speakers Diy|Amplifier| - AliExpress
And a fully cased dual TPA3221 -
HIFI Dual TPA3221 Digital Power Amplifier Board 2*120W Class D Stereo Audio Amplifier|Amplifier| - AliExpress
Linuxfan your first link is since january on ali. I own it. Very good amp. Good components and quality. No noise, blops and so.
2nd link is dual mono. Same brand also have Stereo TPA3221.
Fever digital power amplifier TPA3221 high definition high power HIFI power amplifier|Home Automation Kits| - AliExpress
All are from a brand calle FR.
2nd link is dual mono. Same brand also have Stereo TPA3221.
Fever digital power amplifier TPA3221 high definition high power HIFI power amplifier|Home Automation Kits| - AliExpress
All are from a brand calle FR.
Hi amigos,
Let me introduce my new little toy )
Dual Mono TPA3221 Amp. Really tiny but impressive : 134x59x90mm
Really well made, PCB exudes quality.
Spec :
- OPA1652
- Anti Pop function / ON OFF
- Panasonic FC Power caps
- WIMA caps
- Elna Audio Grade buffer caps
- Evox Film caps
- TPA3221 main chip
- PSU 15V / 7A
At first listening, amplifier is dead silent and sound awesome !
Will give a long listening test later vs Hypex vs Purifi.
Videos :
VID_20210329_205042
VID_20210329_205219
Some pictures in te meanwhile :
Let me introduce my new little toy )
Dual Mono TPA3221 Amp. Really tiny but impressive : 134x59x90mm
Really well made, PCB exudes quality.
Spec :
- OPA1652
- Anti Pop function / ON OFF
- Panasonic FC Power caps
- WIMA caps
- Elna Audio Grade buffer caps
- Evox Film caps
- TPA3221 main chip
- PSU 15V / 7A
At first listening, amplifier is dead silent and sound awesome !
Will give a long listening test later vs Hypex vs Purifi.
Videos :
VID_20210329_205042
VID_20210329_205219
Some pictures in te meanwhile :
Last edited:
Again, very nice amp and construction!
It´s a linear voltage regulator which is eventually and directly fed from the main supply.
I can´t really calculate it exactly because the current numbers are given when the device operates without sound.
But according to the datasheet there´s probably about 50mA drawn from the 5V supply as it looks on first sight (IVDD+IAVDD+IGVDD).
That would be 0.5W dissipated by the regulator at 15V which should be OK.
At 30V this would be 1.25W which would equate to a considerable rise in junction temperature depending on the cooling PCB area saved for the chip
and eventually much too hot long-term.
The numbers could be slightly off but watch out if you connect your 24V supply again which isn´t an intended supply voltage as it seems.
There you´d have about 0.95W power dissipation.
Maybe you can run it at 24V and then carefully feel how hot the regulator gets. That said have a look first if there´s any capacitors with <25V rating ;-)
I guess that´s the culprit why they have a supply voltage of only 15/16V max.
It´s a linear voltage regulator which is eventually and directly fed from the main supply.
I can´t really calculate it exactly because the current numbers are given when the device operates without sound.
But according to the datasheet there´s probably about 50mA drawn from the 5V supply as it looks on first sight (IVDD+IAVDD+IGVDD).
That would be 0.5W dissipated by the regulator at 15V which should be OK.
At 30V this would be 1.25W which would equate to a considerable rise in junction temperature depending on the cooling PCB area saved for the chip
and eventually much too hot long-term.
The numbers could be slightly off but watch out if you connect your 24V supply again which isn´t an intended supply voltage as it seems.
There you´d have about 0.95W power dissipation.
Maybe you can run it at 24V and then carefully feel how hot the regulator gets. That said have a look first if there´s any capacitors with <25V rating ;-)
Hi amigos,
Here a short review about the dual TPA3221 :
I should specify in advance that I am not a professional and even less a test laboratory Audio test, so this review is subject to subjectivity) I got tackled irreverently by a very unpleasant member: Polevka !
Setup :
DAC : Gustard X16
Amp 1 : Hypex NC252MP
Amp 3 : Dual TPA3221 / OPA1652 (stock PSU 15V / 7a + FX Audio 24V / 4A PSU)
Amp 4 : HanZao TPA3255 / OPA1692 + Shui Yuan OPA1656
Playlist : HD audio via LDAC BT
Indroduction :
This dual TPA3221 is really small about 134x59x90mm, compared to the Aiyima A04 for example : 150X92x40mm.
The case is a full alu black enclosure, it's still pretty basic but rather robust. The connectors are pretty good and seem solid.
Under the Case, we therefore discover two distinct TPA3221 boards with a really surprising PCB. I would say the components seem to be of good quality
We see some Samsung FC power caps 35V@ 1800uf / Evox Film caps / Elna Audio caps / OPA1656.
The spec of the TPA3221 are available here otherwise:
TPA3221 data sheet, product information and support | TI.com).
I did not measure the amp but in Living room (30m²) with my 2.5 floor speakers, the power is more than enough to drive my speakers under 8 ohms with a more than comfortable volume even with the stock PSU.
I made a 1h30 listening test yesterday VS my other amps and here are my observations with my favorite Playlist :
Bass :
Complex song : Downtown (Yellowjackets & WDR) : The bass is very well maintained, it is precise and it does not drool. Blindfolded, it is very difficult to perceive a difference in the human ear vs my Hypex NC252. Although I'm convinced the Hypex is better on paper. With the 24V PSU we gain slightly in power but it's also really good with the stock PSU. I hope that future reviews will confirm my opinion but the bass is tight and very present despite its small size)
Medium :
Audiophila Master CD18 : Voices stand out very well from the mix, they are well put forward. I found a very silky side in the mids, the amp is closer to the TPA3255 Hanzao / OPA1692 than to the Shui Huan OPA1656. I find my Hypex NC252 better in this register, however. Either way, I didn't find listening tiring.I let myself be carried away by the softness of the amp without any problem.
Trebles :
Being a drummer, I am particularly sensitive to this point. I used to collect cymbals and have a ticklish ear lol ) With the Drum Collections HD files : I found it to be very good, the rides are subtle, the crashes stand out without aggressiveness (I use a ribbon tweeter). Compared to my Hypex NC252, frankly it's quite impressive! We tickle his performance level. Overall very good behavior in the treble.
Soundstage :
Impressive! I have always found that dual mono configurations were more interesting on this point.
Audiophila Master CD 17 : Everything is well detached, the instruments are well distributed.
We find the signature of the TPA chips, it's as good as my TPA3255. I have always liked the TPA325X regarding the Soundstage and I am not disappointed here.
Negative points :
- The volume is reversed, we increase by going to the left) (can be corrected easily anyway)
- I would have preferred a Power Switch on the front for accessibility reasons
- With the 24V PSU, a tiny Pop sound when Switching ON only. Nothing to complain with the 15V.
- A strange behavior that I also observed: the start sequence is important here: I have to turn on my DAC before the amp otherwise I have a marked pop.
- No DIP8 op amps socket but OPA1652 seem really good !
Conclusion :
I paid the amp 56 euros ! It is a little bomb for this price : it is a small / compact and sounds very good. He does not blush in front of my Hypex and he will convince most ears. It lacks a bit of power it's true! But for a listening at moderate volume it is enough believe me! It is not at the level of my Purifi that is about 20X more expensive)))
At this price you will not take any risks! I think this little dual Mono TPA3221 is a great choice for less fortunate wallets.
VID_20210329_205042
VID_20210329_205219
Here a short review about the dual TPA3221 :
I should specify in advance that I am not a professional and even less a test laboratory Audio test, so this review is subject to subjectivity) I got tackled irreverently by a very unpleasant member: Polevka !
Setup :
DAC : Gustard X16
Amp 1 : Hypex NC252MP
Amp 3 : Dual TPA3221 / OPA1652 (stock PSU 15V / 7a + FX Audio 24V / 4A PSU)
Amp 4 : HanZao TPA3255 / OPA1692 + Shui Yuan OPA1656
Playlist : HD audio via LDAC BT
Indroduction :
This dual TPA3221 is really small about 134x59x90mm, compared to the Aiyima A04 for example : 150X92x40mm.
The case is a full alu black enclosure, it's still pretty basic but rather robust. The connectors are pretty good and seem solid.
Under the Case, we therefore discover two distinct TPA3221 boards with a really surprising PCB. I would say the components seem to be of good quality
We see some Samsung FC power caps 35V@ 1800uf / Evox Film caps / Elna Audio caps / OPA1656.
The spec of the TPA3221 are available here otherwise:
TPA3221 data sheet, product information and support | TI.com).
I did not measure the amp but in Living room (30m²) with my 2.5 floor speakers, the power is more than enough to drive my speakers under 8 ohms with a more than comfortable volume even with the stock PSU.
I made a 1h30 listening test yesterday VS my other amps and here are my observations with my favorite Playlist :
Bass :
Complex song : Downtown (Yellowjackets & WDR) : The bass is very well maintained, it is precise and it does not drool. Blindfolded, it is very difficult to perceive a difference in the human ear vs my Hypex NC252. Although I'm convinced the Hypex is better on paper. With the 24V PSU we gain slightly in power but it's also really good with the stock PSU. I hope that future reviews will confirm my opinion but the bass is tight and very present despite its small size)
Medium :
Audiophila Master CD18 : Voices stand out very well from the mix, they are well put forward. I found a very silky side in the mids, the amp is closer to the TPA3255 Hanzao / OPA1692 than to the Shui Huan OPA1656. I find my Hypex NC252 better in this register, however. Either way, I didn't find listening tiring.I let myself be carried away by the softness of the amp without any problem.
Trebles :
Being a drummer, I am particularly sensitive to this point. I used to collect cymbals and have a ticklish ear lol ) With the Drum Collections HD files : I found it to be very good, the rides are subtle, the crashes stand out without aggressiveness (I use a ribbon tweeter). Compared to my Hypex NC252, frankly it's quite impressive! We tickle his performance level. Overall very good behavior in the treble.
Soundstage :
Impressive! I have always found that dual mono configurations were more interesting on this point.
Audiophila Master CD 17 : Everything is well detached, the instruments are well distributed.
We find the signature of the TPA chips, it's as good as my TPA3255. I have always liked the TPA325X regarding the Soundstage and I am not disappointed here.
Negative points :
- The volume is reversed, we increase by going to the left) (can be corrected easily anyway)
- I would have preferred a Power Switch on the front for accessibility reasons
- With the 24V PSU, a tiny Pop sound when Switching ON only. Nothing to complain with the 15V.
- A strange behavior that I also observed: the start sequence is important here: I have to turn on my DAC before the amp otherwise I have a marked pop.
- No DIP8 op amps socket but OPA1652 seem really good !
Conclusion :
I paid the amp 56 euros ! It is a little bomb for this price : it is a small / compact and sounds very good. He does not blush in front of my Hypex and he will convince most ears. It lacks a bit of power it's true! But for a listening at moderate volume it is enough believe me! It is not at the level of my Purifi that is about 20X more expensive)))
At this price you will not take any risks! I think this little dual Mono TPA3221 is a great choice for less fortunate wallets.
VID_20210329_205042
VID_20210329_205219
Last edited:
Yes it is enough, keep in mind it is a dual Mono setup. So it is more powerful than the twin version here :
Amplificateur de puissance numerique fievre TPA3221 amplificateur de puissance HIFI haute definition haute puissance | AliExpress
They raised the price right after I bought it, I saw it! I am lucky I confess)
Huo guang Store sold them for less than 60 euros ...