• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Breeze TPA3255 XLR Balanced Amplifier TearDown : DIP8 Op Amps.

ToniESP

New Member
Joined
Jan 28, 2023
Messages
4
Likes
1
Yes, you have correctly generalized the easiest and most obvious modifications of this amplifier:
1. replace operational amplifiers with better ones (to your taste).
2. replace the 4 original Wima Caps 1µF or 2,2µF with 10µF to reduce phase distortion of the input signal.
Next are non-obvious modifications that can cause controversial opinions about their expediency:
3. if you have large speakers with 10 or 12-inch drivers, then you need to replace four 470µF/50V capacitors with two (three/four) LowESR 2200µF/63V electrolytic capacitors (this will be enough to provide dynamics at low frequencies). To test the dynamics at low frequencies, you can use these two audio-tracks. When listening through a good quality amplifier, the sound of a bass drum from first track resonates in your chest and makes it difficult to breathe.
4. replace the 30 kOhm resistor with 10 kOhm, which raised the frequency of the modulator from 450 kHz to 600 kHz. This will cause increased heating of the TPA3255 chip, so it is necessary to make ventilation holes in the upper cover of the case.
5. shunting a 220uF/63V electrolytic capacitor to power the chip TPA3255 with a 1nF/100V film capacitor to remove some of the high-frequency ripples.
6. we improve the quality of the power supply of operational amplifiers and the modulator in TPA3255 by replacing the parts around the converter voltage from 36-50V to 12V LM2575HV.

I made all six of these modifications on my amplifier and am pleased with their result! :)

1. View attachment 246438 or View attachment 246439
2. View attachment 246440 View attachment 246441 View attachment 246447
3. View attachment 246443 View attachment 246442
4. View attachment 246444 View attachment 246445
5. View attachment 246446
6. View attachment 246451 View attachment 246449 View attachment 246448 View attachment 246450
Hello,

Thank you for the detailed information regarding your amplifier modifications.

I was inspired by this idea and made modifications exactly according to your suggestions for choosing parts from Mouser and of course I changed the voltage to 42V.

Unfortunately, I have a problem - after turning on the amplifier, the inductor (Murata 19E225C) begins to heat up and smoke. This is not a disadvantage of this coil - I replaced it with a new one and the effect is the same, unfortunately ... What can cause this problem, should I use a different inductor? I compared the Murata 19E225C datasheet with the coils mentioned in the LM2575-12V datasheet and for example the Renco RL2448 is identical to the Murata 19E225C ...?

I enclose some photos and I will be grateful for any advice.

Greetings to all forum users.
 

Attachments

  • IMG_0736.JPG
    IMG_0736.JPG
    211.3 KB · Views: 120
  • IMG_0738.JPG
    IMG_0738.JPG
    353.2 KB · Views: 120
  • IMG_0740.JPG
    IMG_0740.JPG
    211.3 KB · Views: 117

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
Unfortunately, I have a problem - after turning on the amplifier, the inductor (Murata 19E225C) begins to heat up and smoke. This is not a disadvantage of this coil - I replaced it with a new one and the effect is the same, unfortunately ... What can cause this problem, should I use a different inductor? I compared the Murata 19E225C datasheet with the coils mentioned in the LM2575-12V datasheet and for example the Renco RL2448 is identical to the Murata 19E225C ...?
Earlier in the discussion I wrote:
"First I set the inductance to 2200µH - there was a lot of RF interference.
Therefore, I installed another inductance, which I had in stock, at 1200µH - the level of interference was greatly reduced..."

And this inductor was wound with a wire designed for load current = 2A.
LM2575HVS_mod__04b.jpg
That is, when designing a reliable power supply circuit, using the rules of the old school, you need to take a current / voltage margin of 2 - 2.5 times more than the calculated figures.
And the inductance values can be from 470µH to 1200µH.
 
Last edited:

ToniESP

New Member
Joined
Jan 28, 2023
Messages
4
Likes
1
Earlier in the discussion I wrote:
"First I set the inductance to 2200µH - there was a lot of RF interference.
Therefore, I installed another inductance, which I had in stock, at 1200µH - the level of interference was greatly reduced..."

And this inductor was wound with a wire designed for load current = 2A.
View attachment 263837
That is, when designing a reliable power supply circuit, using the rules of the old school, you need to take a current / voltage margin of 2 - 2.5 times more than the calculated figures.
And the inductance values can be from 470µH to 1200µH.
Thank you for your explanations. This is my mistake - I did not read this thread carefully. I've already ordered new parts from Mouser and I'm getting to "work" ...
 

NorTroll

Member
Joined
Feb 13, 2023
Messages
6
Likes
0
Hello! Been following this thread for a while, and decided to purchase one of these amps for myself!
Without modifications I must say I do enjoy the sound of the amp. But I do have a few questions, if referencing v1adpetrov2s list of 6 mods on the previous page. Does any of them make it so I have to do more mods? My initial thoughts are that I wanna do mod 1,2 and 3.

Secondly, I'm having an issue where after about 20 minutes of casual listening, I will lose sound on one channel. That channel proceeds to play a certain amount of white noise that isn't affected by the volume. If I turn it on and off again the problem sorts itself. Any common causes for this?

-NorTroll
 

NorTroll

Member
Joined
Feb 13, 2023
Messages
6
Likes
0
Hello! Been following this thread for a while, and decided to purchase one of these amps for myself!
Without modifications I must say I do enjoy the sound of the amp. But I do have a few questions, if referencing v1adpetrov2s list of 6 mods on the previous page. Does any of them make it so I have to do more mods? My initial thoughts are that I wanna do mod 1,2 and 3.

Secondly, I'm having an issue where after about 20 minutes of casual listening, I will lose sound on one channel. That channel proceeds to play a certain amount of white noise that isn't affected by the volume. If I turn it on and off again the problem sorts itself. Any common causes for this?

-NorTroll
Sorted out the issue i was having, was caused by a bad RCA cable.

Any list where i can compare opamps anywhere?
-NorTroll
 

ToniESP

New Member
Joined
Jan 28, 2023
Messages
4
Likes
1
Thank you for your explanations. This is my mistake - I did not read this thread carefully. I've already ordered new parts from Mouser and I'm getting to "work" ...
Thanks again for this detailed information regarding your amp modifications.
I corrected my mistakes and made the modification exactly according to your recent suggestions on the selection of parts from Mouser and of course changed the voltage to 42V.
I have complete success! In fact, I should write that I am delighted with such a positive change in the overall dynamics and sound quality of this amplifier. I do not have the ability to make measurements, but I have two such amplifiers - so I directly compare the unmodified and modified one - playing the mono file on parallel amplifiers.

I also want to replace the 30kohm resistor with a 10kOhm one - is the one from Mauser 279-RP73D2A10KBTG suitable?
 

Attachments

  • IMG_0752.JPG
    IMG_0752.JPG
    178.8 KB · Views: 100
  • IMG_0756.JPG
    IMG_0756.JPG
    196.9 KB · Views: 103

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
I also want to replace the 30kohm resistor with a 10kOhm one - is the one from Mauser 279-RP73D2A10KBTG suitable?
Resistor 279-RP73D2A10KBTG is suitable for replacement.
But!!! This will cause increased heating of the TPA3255 chip, so it is necessary to make ventilation holes in the upper cover of the case.
Think twice - do you need it?
BRZHIFI_Balanced_(TPA3255)_original_17.jpg
 

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
My board is version 1.5 and the issue was actually not resolved it seems. Had a period of good luck where it did not trigger safety mode. Trying to figure out what causes it to trigger safety mode.
1. Disconnect the speaker from the amplifier and measure its resistance with a tester: if it is less than 3 Ohms, the TPA3255 chip will overheat and the protection will turn on.
Then the problem is in the technical condition of the speakers or crossover.
2. The manufacturer forgot to apply thermal paste to the radiator of the chip, in connection with which overheating occurs and protection is turned on.
 

NorTroll

Member
Joined
Feb 13, 2023
Messages
6
Likes
0
1. Disconnect the speaker from the amplifier and measure its resistance with a tester: if it is less than 3 Ohms, the TPA3255 chip will overheat and the protection will turn on.
Then the problem is in the technical condition of the speakers or crossover.
2. The manufacturer forgot to apply thermal paste to the radiator of the chip, in connection with which overheating occurs and protection is turned on.
Hello, checked all the speakers I've tested with, they all measure at least 4ohms on my multimeter. And I have reapplied thermal paste to make sure it's a good amount. Is there anything other than overheating that can cause me to lose power on one channel? It happens even without volume. I'm thinking that maybe one of the relays are broken or something like that. Thank you for the reply.
 

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
I'm thinking that maybe one of the relays are broken or something like that. Thank you for the reply.
Checking the relay is easy.
After the signal disappears in the loudspeaker, try to close the contacts of the input from the XLR and the signal output from the relay (red stripes in the photo).
If the sound appears in the speaker, then the relay is really faulty.
BRZHIFI_Balanced_(TPA3255)_relay_short.jpg
 

NorTroll

Member
Joined
Feb 13, 2023
Messages
6
Likes
0
Checking the relay is easy.
After the signal disappears in the loudspeaker, try to close the contacts of the input from the XLR and the signal output from the relay (red stripes in the photo).
If the sound appears in the speaker, then the relay is really faulty.
View attachment 266799
since i do not have any xlr preamps, which ones are for the rca in and relay out? are there anything else that can cause the amp to behave the way it is? all speakers are measuring 7ohms, sound is there for 20-30 seconds before it makes a pop noise and sound on left channel goes away, chip never gets hot, power on output from power supply stays at 36v, i enjoy troubleshooting this but i soon have to send a refund request if i can not fix it.
 
Last edited:

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
since i do not have any xlr preamps, which ones are for the rca in and relay out? are there anything else that can cause the amp to behave the way it is? all speakers are measuring 7ohms, sound is there for 20-30 seconds before it makes a pop noise and sound on left channel goes away, chip never gets hot, power on output from power supply stays at 36v, i enjoy troubleshooting this but i soon have to send a refund request if i can not fix it.
BRZHIFI_Balanced_(TPA3255)_relay_short2.jpg
 

Calleberg

Active Member
Joined
Aug 23, 2021
Messages
101
Likes
136
Location
Sweden
Hello! Been following this thread for a while, and decided to purchase one of these amps for myself!
Without modifications I must say I do enjoy the sound of the amp. But I do have a few questions, if referencing v1adpetrov2s list of 6 mods on the previous page. Does any of them make it so I have to do more mods? My initial thoughts are that I wanna do mod 1,2 and 3.

Secondly, I'm having an issue where after about 20 minutes of casual listening, I will lose sound on one channel. That channel proceeds to play a certain amount of white noise that isn't affected by the volume. If I turn it on and off again the problem sorts itself. Any common causes for this?

-NorTroll

My 2.1 BRZ TPA3255 amp (non XLR model) does a similar thing. But I can have music playing forever if I do not play very loud.

There are a few comments about similar issues in the Reviews from others that bought it and also at least one Youtube review with this issue.

It is the overcurrent protection that kicks in prematurely. Only Overcurrent and Overtemp needs a powercycle to Reset.
I hooked up a DMM to it and Current peaks of just over 2A triggers the protection like clockwork.

There is a resistor(resistors? don't rember exactly, did this over a year ago) that sets the current range/mode for the protection. But that checked out ok. In fact Everything checks out ok, Heat sink thermal paste is there. The amp chip solder connections look good, like everything else on the circuit board.

So, there is only two or maybe three possible failure modes here really.

#1 There IS an actual overcurrent situation, but in the HF domain, that means that a cap or coil in (most likely) the output filter is more or less shorting the Carrier to ground (saturating inductors maybe?). This would fit well with the behaviour of your amp, as the Carrier HF is on even without input signal, it also fits how my amp behaves, if in my case the component shorting the hf is just a little less faulty. ( being HF current a generic DMM, even a Fluke 179 like mine will not pick this up)

#2 Faulty/ Fake Amp Chip

#3 Same as #1 But related to Circuit board layout, improper layout causing parasitic capacitance which could also act as a short for HF, less likely as such a parasitic capacitance and HF current draw would have to be pretty substantial, I don´t think something of that magnitude would be possible and it also does not fit well with your failure mode as well as it does mine.

#4 A combination of the above :)

I have not done any modifications to my amp as I find it a waste of time. Nor have I made any serious effort to fix the actual issue I have. Instead I moved on and bought some Hypex UCD180 Modules.

I did eventually get a replacement board from BRZ that I have yet to try though.

Hope this helps...
 
Last edited:

NorTroll

Member
Joined
Feb 13, 2023
Messages
6
Likes
0
okay, so update! my amplifier got fully refunded, and i blew the tpa chip when i accidentally shorted pin1 and 2 on the lm2575. currently looking at two options. 1 i order parts and fix the amplifier as it is, with potential upgrades, there are some bridged pads where the tpa3255 gets soldered to the board, but they are all connected either way, so i figgured that wont be an issue.

My option two, and this is the one i am most unsure about - It does sound like the option i will enjoy the most, and learn the most from.
I design a new pcb, Solder wires from the outputs of both opamps or anywhere from the outputs where its feasible to do so, assemble the new pcb with standoffs, bringing the new pcb high enough that i will have a protruding heatsink. Possible making room underneath for the bigger capacitors to fit. all while having a good time.

But i do have a few questions, why did they put 1k resistors between outputs on opamps and the 10uF caps for the inputs on the tpa3255?
is pin 4? on the relays supposed to go to ground?
And does any1 have suggestions as to what the best way of utilizing the fault and clip outputs on the tpa3255 is?
I desoldered quite a bit now, so if any1 wants a picture of the board pretty bare bones i'm more than willing to take a picture :)
1678750469868.png
 

v1adpetrov2

Member
Joined
Sep 24, 2022
Messages
84
Likes
83
But i do have a few questions, why did they put 1k resistors between outputs on opamps and the 10uF caps for the inputs on the tpa3255?
is pin 4? on the relays supposed to go to ground?
1. Resistors of 1 kOhm are needed to protect the outputs of operational amplifiers, if the TPA3255 chip suddenly burns out and an increased voltage appears on pins 5, 6, 16 and 17.

2. Yes! Pin 4 on the relay must be earth-locked.
 

Peter-ht

New Member
Joined
Mar 30, 2023
Messages
3
Likes
0
I also have problems with the amplifier (brz xlr) shutting down if I try to play loud.
Bought it because of the bigger power supply, but what does it do when the amp just shuts down.
Played before on a YJ-D01 TPA3255 without problems with 36V 6A power supply, so it's not the speakers (6 ohms) that cause problems.
What are your suggestions on where to start troubleshooting the amplifier?
 

Schlippwhip68

Addicted to Fun and Learning
Joined
Nov 28, 2020
Messages
511
Likes
198
Location
Essex, UK.
Hi amigos )

As promised, I am sharing some spec and pictures about the new Breeze Audio TPA3255 amplifier.
This is the only full balanced finished amp that I found for less than $200 )

The amp comes in an black aluminum case of modest size but seems robust however.
In the front plate you will find the RCA / XLR inputs selector with that motorized volume pot and the ON/OFF switch
I am still wondering why spending so much money on a motorized potentiometer since the amp doesn't have a remote...

The speakers banana connectors are OK and seem solid.
The XLR connectors are OK as well with a secure clip. RCA inputs are conventional
I do not observe any play on the volume knob and nothing to complain with.
You can see that the inside speaker cables and PSU to module cables are directly soldered to the PCB. (no JST connector here)

Safety is important: the amplifier is properly grounded ) Nice for a Chinese amp. )
BUT :the neutral and the phase were reversed... I corrected it )

Little mod I made :

- Update OP amps > OPA2210 (crazy op amps, give a try really !)
- Twisted the 220V cables
- Reversed the Neutral / Phase properly
- Insulated the PSU to module 36V cable
- added ferrites on the speaker cables
- added copper film to the transformer core

Listening test still in progress. But after 1 hour I can say; dead silence (even with my ears glued to the speakers) I only tested the XLR inputs with my Gustard A18 DAC.
The OPA2210 definitely worth trying! as good of the OPA1656 in term of Soundstage but with the best of the OPA1692. This super BETA Bipolar OP amps is really fast with a very low DC offset. The amplifier sounds great and very loud with the volume @ 30%. I tried to turn the volume @Max, it remains ultra silent, good point here.
For the rest, I can't say too much more, it's too early....

NB : I ve been testing many OP amps all Genuine from Mouser : OPA1622 / 1656 / 1612 / 1692 / 2210



TPA3255 MODULE :

WIMA MKS Caps (next to the volume pot) = 2U2J63 2.2uf / 63V
Electrolytic SMD Caps next to the OP amps = 220uf / 16V
Panasonic FC caps between inductors : 50V / 220uf
Switching Voltage Regulator = TI LM2575S-12
Electrolytic SMD Caps next to the Voltage regulator = 220uf / 16V
Power caps next to XLR inputs : 470uf / 50V
Polypropylene Film Capacitors : MKP10 / 0.1-250
Hongfa Relay = HFD4 / 5-S
Sagami Inductors
Volume pot : Alps Motorized Quadrirotor RK168 100K 100KAX4

PSU :

SMPS PSU 36V / 9.5A @342W
Epsilon 400uf / 400V x2
United Chemicon 1000uf / 50V x 4
Stable @ multimeter !

















Please excuse me for my ignorance but I have just purchased one of these and wondering if you could point out the neutral and phase and how you corrected it as I may need to do the same.
 
Top Bottom