Breeze TPA3255 XLR Balanced Amplifier TearDown : DIP8 Op Amps.

[Doodski]

If it was a joke it is missed because it is in bad taste but if it was written to say nothing: it is perfectly successful.

I think we have some sort of crossed wires going on with our commentary.

 

[SMen]

I think we have some sort of crossed wires going on with our commentary.

No ... just think your wires "short circuited" before posting ... my son is 5 and he is really into his dinosaurs ... so was I come to think of it.

 

[v1adpetrov2]

You are wrong about the feeding of OPAMPS: I made a survey of part of the diagram that is ->
The power supply of our OPAMPS is unipolar, which explains the presence of a single SMD capacitor of 10μF decoupling (on the positive necessarily ) just above the location of the OPAMPS.

I have mentioned in my partial diagram a kind of explanation of the choices for the values of capacities.
(I did not represent the Chinese "decoupling bases")

Your opinion ?

Yes, you are right - this is really a non-inverting amplifier with a unipolar power supply.
Here is the classic scheme:

And this is the scheme in BRZHIFI 3255XLR:

The upper and lower capacitors must be of the same capacity, otherwise there will be a strong voltage difference after the divider on the 22K resistors.

 

[ICIETDIYEUR]

Hi v1adpetrov2

Great: we're moving forward

You are much more gifted than me in diagram it is obvious and especially you master a dedicated software:
it is much more presentable than the "draft" of someone who lacks hours of sleep

Otherwise i changed the values of two capacitors to 330u, here is my thought:
470u (VDD TPA3255) + 330u 5 (TOP CAPACITOR) + 330u (BOTTOM CAPACITOR) = 1130u TOTAL

So I chose the value of 1200u for Cout ot the LM2575 regulator ->

From MOUSER (some component details) ->

PANASONIC 1200µF - 10000H - ESR 20 mOhms
PANASONIC 330µF - 6000H - ESR 56 mOhms
PANASONIC 100µF - 8000H - ESR 68 mOhms

Is it correct ?

I also noticed that you seem to be using an OPA1652 while I am using an OPA1656:
What are the reasons for your choice ?

Regards.

 

[v1adpetrov2]

The capacitor at the output of the LM2575HVS (Cout) simultaneously performs the function of a 470mkF capacitor from the datasheet on the Vdd TPA3255.
I repeat once again - choose the capacitor ratings as you see fit, but within reasonable limits. We discussed the limits earlier...
The Panasonic 1200uF has too low ESR = 0.02 Ohm.
As you yourself quoted the datasheet: "However, when operating in the continuous mode, reducing the ESR below 0.05Ω can cause instability in the regulator".

I use op-amp OPA1656.
Just in the library of elements of the scheme editor EasyEDA there was a suitable icon from OPA1652.

 

[ICIETDIYEUR]

Oooops !

Thank you, I had not noticed this very important detail

Here is the diagram with the components I reselected ->

Why did you change the value of the inductor from 2200 to 1200 μH ?

Always from MOUSER ->

WURTH 1000µF - 10000H - 90MΩ (710-860160478028)
PANASONIC 220µF - 6000H - 56MΩ (667-EEU-FR1E221)
PANASONIC 100µF - 8000H - 68MΩ (667-EEU-FR1J101L)

Is it OK now ?

(Thank you for telling me EASYDEA )

 

[v1adpetrov2]

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...
Suitable model from MOUSER -> 994-RFC1010B-125KE

As for the capacitors:
WURTH 1000µF - 10000H - 90mΩ (710-860160478028) - OK!
2 * PANASONIC 330µF (667-EEU-FR1E331B , ESR=56mΩ, 6000H) or 470µF (667-EEU-FK1E471 , ESR=63mΩ, 4000H) - - it will be better!
PANASONIC 100µF 63V - 8000H - 68mΩ (667-EEU-FR1J101L) - OK!

 

[ICIETDIYEUR]

Hello v1adpetrov2

I redid the diagram taking into account your advice

I have reported the necessary values and indications concerning the components.
(I found 470μF with almost identical characteristics but with an almost double lifespan )

Here it is ->

But, I have retained what you observed with the inductor and it seems that the value of 1200μH is not yet well adapted if we refer to Figure 5 of the datasheet of the regulator ->

Indeed if we interpret the table as it seems (to me) to be, the value of the inductor must be between 220μH and 680μH depending on the load applied but also the input voltage.

By respecting this we would be obliged to reduce this input voltage according to the indications of the table

But I could (surely) be wrong or I misunderstood the "table"...

(Normal, I'm French: "No one is perfect" )

What do you think ?

 

[v1adpetrov2]

“Practice is the criterion of truth!”
We have considered the theory in detail. It's time to move on to practice...

 

[ICIETDIYEUR]

Hi v1adpetrov2

You are right

But my principle is to always think before acting.
(What I don't necessarily do when it comes to talking...)
I can't help it, I'm like that

Kind regards.

 

[Polkern]

Hi v1adpetrov2

You are right

But my principle is to always think before acting.
(What I don't necessarily do when it comes to talking...)
I can't help it, I'm like that

Kind regards.

well, and this one of the few real experts on this forum said I'm checking. And the silence fell ...

 

[Polkern]

maybe let's chill out - two weeks ago I received 2 pcs of these amplifiers from alixspress. And well they sound like all worthless Chinese tp3255. No matter if it's from xlr or rca - of course I connected the speakers easily 4-6 ohm ... Well, unfortunately, sharp thanks and no bass ... Did I "burn in" the amplifier? Yes, 48 hours ... Did I change the OPA and the separating base will recommend on the forum (yes, I also bought it) it didn't change anything ... so sorry, why these soldering guidelines and so on?

I will also add that it is not that every Chinese amplifier is technically badly built! there are professional engineers and it's about value for money - Chinese engineers of course know how to build hi-end but they have to sell cheap ...

 

[SMen]

maybe let's chill out - two weeks ago I received 2 pcs of these amplifiers from alixspress. And well they sound like all worthless Chinese tp3255. No matter if it's from xlr or rca - of course I connected the speakers easily 4-6 ohm ... Well, unfortunately, sharp thanks and no bass ... Did I "burn in" the amplifier? Yes, 48 hours ... Did I change the OPA and the separating base will recommend on the forum (yes, I also bought it) it didn't change anything ... so sorry, why these soldering guidelines and so on?

I will also add that it is not that every Chinese amplifier is technically badly built! there are professional engineers and it's about value for money - Chinese engineers of course know how to build hi-end but they have to sell cheap ...

For me standard chip sounded ok, not sharp, and quite like Aiyima A08, but more control. The OPA1656 extended bass and opened soundstage. I think the type of OPA matters. I use Triangle speakers and a variety of good quality sources, both digital and vinyl. I also tried the isolation base, but I have just put it in. In a couple of weeks I will properly compare with, and without it in place.
It sounds as if @v1adpetrov2 and @ICIETDIYEUR are finalizing their two modification paths. For me the OPA1656 was worth it, and it has been interesting to follow . Balanced makes an improvement with my balanced phono pre-amp.

 

[Polkern]

Dla mnie standardowy chip brzmiał ok, niezbyt ostro i całkiem jak Aiyima A08, ale z większą kontrolą. OPA1656 rozszerzył bas i otworzył scenę dźwiękową. Myślę, że rodzaj OPA ma znaczenie. Używam głośników Triangle i różnych dobrej jakości źródeł, zarówno cyfrowych, jak i winylowych. Wypróbowałem też bazę izolacyjną, ale właśnie ją założyłem. Za kilka tygodni dokonam właściwego porównania z i bez niej na miejscu.
Wygląda na to, że @v1adpetrov2 i @ICIETDIYEUR finalizują swoje dwie ścieżki modyfikacji. Dla mnie OPA1656 był tego wart, a śledzenie go było interesujące . Zbalansowany stanowi ulepszenie w moim zbalansowanym przedwzmacniaczu gramofonowym.

hello and thank you for your good advice. I had no experience with replaceable opams in amps before. I have a lot of stock class A and AB amps, also tubes like classic triode, and also class D - hypex and icepower, also my own DIYs built on Pascal modules combined with dsp fouraudio - with the right speakers all are perfect. Of course, none of these amplifiers (maybe except for the triode) can replace op-amps, but none of them costs as much as the BRZII - a paltry 140 euros. So I tried what it was like and bought "some" opams from the official distribution in the EU. And I'm surprised it worked - in short, the best I got (strong bass base, good midrange) is the separating base (I think it's the most fragrant from listening) and the MUSES 8820 D opamp ... Thank you to everyone on the forum for interesting information. .. I'm happy to have new toys in a man's world.
In order to maintain "indifference" in hearing, I listened to the 4 ohm Jamo Concert 11 and Concert 8 - not used by me for a long time, but built on excellent Seas transducers.
I forgot to add that I also tried OPA1656 and it is too sterile and narrows the soundstage but better than the factory one.

 

[SMen]

I think you should stay in English here for us Frenchies and Northern Irish ...
I think it is worth trying FET, and OPA1656. There are details in this forum thread from @v1adpetrov2 and@ @ICIETDIYEUR (as to why) and @daniboun in many posts (but not this one) about this FET and the TPA3255.

 

[Polkern]

I think you should stay in English here for us Frenchies and Northern Irish ...
I think it is worth trying FET, and OPA1656. There are details in this forum thread from @v1adpetrov2 and@ @ICIETDIYEUR (as to why) and @daniboun in many posts (but not this one) about this FET and the TPA3255.

Lewandowski didn't score a penalty and you suddenly ask about some posts?

 

[SMen]

... lets not talk about snooker! ...

not sure many will get that... at least he did not put it over the top... and the competition goes on.

hifi here awaits ... @ICIETDIYEUR will need to recover a little from his celebrations after France vs Australia!

 

[Polkern]

... lets not talk about snooker! ...

not sure many will get that... at least he did not put it over the top... and the competition goes on.

hifi here awaits ... @ICIETDIYEUR will need to recover a little from his celebrations after France vs Australia!

what kind of snooker - this is men's divine football

 

[ICIETDIYEUR]

People hi

The MUSES 8820 (BIPOLAR) does not have the best features ->

However, it has sometimes happened to me that some OPAMPS with excellent technical characteristics had given less good listening results than others much less good.
The subjectivity produced by our hearing is not the same for everyone: it is based on personal preference and cannot be swept away by even objective measures.

Not everyone has measuring instruments but most of the time, listeners all have one thing in common: hearing but which remains different for each person without talking about reference in terms of 'sound signature'...
... Everyone is free to appreciate or not a sound reproduction device, whatever the criteria

Question: You have not tested OPAMP FET like MUSES 01 or MUSES 8920 ?

Kind regards.

 

[Polkern]

Thank you for this factual question. Yes, I have all these opamps and I tested them in this cheap amplifier and in my opinion - I note that in my opinion only in terms of sound - the 01 muses are the best but also the most expensive and it also depends on what kind of music. In addition to the the ridiculous price of this amplifier (I compared it with the reference moim diy Pascal for 1800 euros 2SE in the official sale) - I also invited a friend of an singer who has absolute pitch - her ears hurt when something sounds false ... "I recorded something - sorry, but due to the championships in Qatar, I will publish it later.
Generally answering the question - what are my ratings from testing these opamps - in my opinion and this is only my subjective assessment - MUSES are musical and OPA 1656 too technical ... Is the old bipolar better than FET - certainly not - everyone can choose it , what he wants.