Which TPA3255 amp do you recommend?

[Ralferator]

It looks like a bluetooth preamp + A07, however A07 has 2 nichicon capacitors and this one has one (if it is original nichicon... lol).
It surely will save you buying additional bluetooth adaptor and gives you tone control which could be handy but I would have just got A07 or A04 along with a separate better bluetooth adaptor keeping amplifier isolated from additional preamp processing.
***** I am not saying that this one is bad though.

From what i read the one capacitor is way enough if you use with a switch mode power supply. I got this recommendation from Toku of this forum who tried out several TPA3255 amps. This one seems to be the same with built in power supply: https://www.aliexpress.com/item/100...earchweb0_0,searchweb201602_,searchweb201603_

But i think the easiest would be to just get a buetooth adaptor then.
Can you tell me about how the Aiyima A07 and A04 compare to the SMSL SA-50 soundwise and powerwise?

 

[vball_max]

Since i had the SMSL SA-50 myself for a while - how would you compare the Aiyima A04 and A07 to it soundwise and powerwise?
For a good sounding and reliable bluetooth-amp i got this one recommended:
https://www.aliexpress.com/item/400...earchweb0_0,searchweb201602_,searchweb201603_

Hi Ralferator,

I didnt have a chance to directly compare the SA-50 to the A07 or A04, and I use this set up in my basement where the sound is not optimal. But from what I am hearing and what I remember from the SA-50, the A07 and A04 are definitely more powerful and a bit cleaner sounding. There is definitely a slightly bigger sound stage and a fuller sound. I think this is to be expected with the much better specs of the A07 and A04.

Thanks for the recommendation of the bluetooth amp. I'll check that one out as well.

 

[vball_max]

The 3E Audio finished amp is just OK.... Measurements show this :



My Shui Yuan sounds better no way !

I saw those measurements in Amir's review...thanks. Also in that review though, he replaced the stock op-amps with the LM4562 and those measurements got much better. The SINAD became over 79db (A07 was 83db i believe) and the THD+N was ~0.01. These numbers put in almost on par with the A07 measurements. Regardless of which amp i get, I will likely switch the op-amp to the OPA1656 based on your recommendations in many posts.

My question was more about the quality of the capacitors, inductors, and the overall set up of the 3 amps. If you have any input on those things, please let me know.

 

[conuss]

Why should the signal pass through the tone block, if it is in both the soft player and the phone? Except for CD disks. If it was shutting down, then it would be a different matter.

 

[Guddu]

I found them here already soldered: https://www.ebay.com/itm/333850298075

Just wondering why you chose OPA1656 but not LM4562NA?
LM4562NA has been tested very well with captured improved performance in this community, comes in 8pin DIP and so just easy to replace.

 

[vball_max]

Just wondering why you chose OPA1656 but not LM4562NA?
LM4562NA has been tested very well with captured improved performance in this community, comes in 8pin DIP and so just easy to replace.

Based on some posts by daniboun and others on diyaudio who have tested the lm4562, opa1656, and many other op amps. They all said the opa1656 (and 1612) sounded better in just about every way over the lm4562. So ill start with the opa1656 and then if I want to try the lm4562 later, I'll do that.

 

[Guddu]

Based on some posts by daniboun and others on diyaudio who have tested the lm4562, opa1656, and many other op amps. They all said the opa1656 (and 1612) sounded better in just about every way over the lm4562. So ill start with the opa1656 and then if I want to try the lm4562 later, I'll do that.

Seems like a plan.

But just thinking in layman terms - would it not just amplify the weak signal, and all we can look for is an opamp which will have low distortion and noise with clean voltage/current amplification?
So in these terms, can anyone explain how would opa1656 be better than LM4562?
Datasheet parameters of these opamps does not suggest anything on any impact on specific Audio frequency range. So how would an opamp demonstrate better mids or high or whatever!

NOTE: It is just an attempt to understand this, don't take it against your choice to choosing one over another. Although overall output would depend on overall topology and its components, but putting this question only focusing on opamp.
Let's see if any technical expert can chime in to help understanding this.

 

[vball_max]

Seems like a plan.

But just thinking in layman terms - would it not just amplify the weak signal, and all we can look for is an opamp which will have low distortion and noise with clean voltage/current amplification?
So in these terms, can anyone explain how would opa1656 be better than LM4562?
Datasheet parameters of these opamps does not suggest anything on any impact on specific Audio frequency range. So how would an opamp demonstrate better mids or high or whatever!

NOTE: It is just an attempt to understand this, don't take it against your choice to choosing one over another. Although overall output would depend on overall topology and its components, but putting this question only focusing on opamp.
Let's see if any technical expert can chime in to help understanding this.

I'm with you. I don't understand all the technically details of the op amps either. I know the lm4562 has a lower noise floor and can reduce the distortion a little from the NE5532 that they come with. But that's as much as I know. I agree, if anyone has a more technical explanation. It would be appreciated.

 

[Synergy4]

OPA1656 TI Design started 2017, preliminary datasheet posted March 2019. Notes on OPA1656: High-Performance CMOS Audio Op Amp: https://www.diyaudio.com/forums/vendor-s-bazaar/335416-opa1656-performance-cmos-audio-op-amp.html

LM4562 Product release around Oct 2006. Notes on LM4562 High-Performance BJT Audio Op Amp was designed and released at National Semiconductor: https://www.diyaudio.com/forums/chi...amplifier-reference-design-6.html#post1575072

Press-release.. LM4562 "High-fidelity audio op amp drops distortion rate to 0.00003 percent"(EEtimes): https://www.eetimes.com/high-fidelity-audio-op-amp-drops-distortion-rate-to-0-00003-percent/#

TI acquired Burr Brown (OPAxxx op amps) in year 2000
https://www.eetimes.com/texas-instruments-to-acquire-burr-brown/

TI acquired National Semiconductor (LMxxx op amps) in 2011.
https://www.eetimes.com/analysis-ti.../?utm_source=eetimes&utm_medium=networksearch

The FET input OPA1656 has lower typical input current noise (6fA/rtHz @ 1kHz vs 1.6pA/rtHz @ 1kHz).

The BJT input LM4562 has lower typical input voltage noise (2.7nV/rtHz @ 1kHz vs 4.3nV/rtHz @ 1kHz).

The OPA1656 has lower typical settling time than the LM4562 (800nS to 0.01%, 10V step vs 1.2uS to 0.1%, 10V step).

The LM4562 has lower typical input offset voltage than the OPA1656 (+/- 0.1mV vs +/- 0.5mV).

 

[Synergy4]

By the way, the Signetics/Phillips/NXP NE/SE5532 op amp is a very old design that was second sourced by many companies (including TI with NE/SE5532 & National Semiconductor LM5532

Here is a 1988 Signetics NE/SE5532 op amp datasheet front page.

 

[vball_max]

OPA1656 TI Design started 2017, preliminary datasheet posted March 2019. Notes on OPA1656: High-Performance CMOS Audio Op Amp: https://www.diyaudio.com/forums/vendor-s-bazaar/335416-opa1656-performance-cmos-audio-op-amp.html

LM4562 Product release around Oct 2006. Notes on LM4562 High-Performance BJT Audio Op Amp was designed and released at National Semiconductor: https://www.diyaudio.com/forums/chi...amplifier-reference-design-6.html#post1575072

Press-release.. LM4562 "High-fidelity audio op amp drops distortion rate to 0.00003 percent"(EEtimes): https://www.eetimes.com/high-fidelity-audio-op-amp-drops-distortion-rate-to-0-00003-percent/#

TI acquired Burr Brown (OPAxxx op amps) in year 2000
https://www.eetimes.com/texas-instruments-to-acquire-burr-brown/

TI acquired National Semiconductor (LMxxx op amps) in 2011.
https://www.eetimes.com/analysis-ti.../?utm_source=eetimes&utm_medium=networksearch

The FET input OPA1656 has lower typical input current noise (6fA/rtHz @ 1kHz vs 1.6pA/rtHz @ 1kHz).

The BJT input LM4562 has lower typical input voltage noise (2.7nV/rtHz @ 1kHz vs 4.3nV/rtHz @ 1kHz).

The OPA1656 has lower typical settling time than the LM4562 (800nS to 0.01%, 10V step vs 1.2uS to 0.1%, 10V step).

The LM4562 has lower typical input offset voltage than the OPA1656 (+/- 0.1mV vs +/- 0.5mV).

Thanks for the great info! Now to research what each of these things mean!

From what I gather, these are both good performing chips. Do you think there will really be an audible difference between the 2 in a typical home audio setup?

 

[estbarul]

Any news on the new Allo Amplifier ?

 

[Toku]

I finally received two Shui Yuan Audio TPA3255 amp boards that I ordered from Aliexpress in early February. China is very close to Japan, but it will take a very long time to arrive due to the reduced number of flights due to COVID-19.

We are currently conducting an operation test immediately, but at the moment when the sound is produced, we notice that the sound quality has evolved from the conventional TPA3255 amplifier.
In particular, I feel that the low end is stretched and the volume of bass is increased.
White noise when there is no sound is really quiet. For the power supply, we use an industrial LLC power supply of 24V / 10A at 30V.

The pop noise when the power is turned on / off does not come out when the power is turned off, but when the power is turned on, the pop noise of anxious level appears.
However, this pop noise can be eliminated by connecting a 47uF capacitor to the RESET / MUTE terminal (hole).
One of the two terminals of RESET / MUTE is pulled up to 3.3V, and the other is GND. When the power is turned on, the charge current of the 47uF capacitor causes RESET operation for a moment to eliminate pop noise. Connecting a capacitor does not affect the RESET / MUTE function.

As reported by other members, I also judge that this amp board is cheap but has very good performance. After this, two red heat sink boards will arrive.

 

[Ralferator]

I finally received two Shui Yuan Audio TPA3255 amp boards that I ordered from Aliexpress in early February. China is very close to Japan, but it will take a very long time to arrive due to the reduced number of flights due to COVID-19.

We are currently conducting an operation test immediately, but at the moment when the sound is produced, we notice that the sound quality has evolved from the conventional TPA3255 amplifier.
In particular, I feel that the low end is stretched and the volume of bass is increased.
White noise when there is no sound is really quiet. For the power supply, we use an industrial LLC power supply of 24V / 10A at 30V.

The pop noise when the power is turned on / off does not come out when the power is turned off, but when the power is turned on, the pop noise of anxious level appears.
However, this pop noise can be eliminated by connecting a 47uF capacitor to the RESET / MUTE terminal (hole).
One of the two terminals of RESET / MUTE is pulled up to 3.3V, and the other is GND. When the power is turned on, the charge current of the 47uF capacitor causes RESET operation for a moment to eliminate pop noise. Connecting a capacitor does not affect the RESET / MUTE function.

As reported by other members, I also judge that this amp board is cheap but has very good performance. After this, two red heat sink boards will arrive.

Great! Did i understand it right? I just have to change the original capacitor for a 47uF capacitor? Does the quality of that capacitor matter or can i just use anything that has 47uF?

 

[Toku]

Great! Did i understand it right? I just have to change the original capacitor for a 47uF capacitor? Does the quality of that capacitor matter or can i just use anything that has 47uF?

This part of the original board has only holes for wiring and no capacitors.
This capacitor has nothing to do with sound quality. This is to delay the startup of the amplifier a little when the power is turned on.
The voltage of the circuit in this part is 3.3V, so any capacitor with a withstand voltage higher than that is OK. The 47uF number is also not severe. I decided by cut and try.

 

[Guddu]

Any news on the new Allo Amplifier ?

Looks like there aren't any info or pictures in internet for new Allo TPA3255 amplifier, not sure why is it so confidential if they are working from years on this!

 

[sychan]

Looks like there aren't any info or pictures in internet for new Allo TPA3255 amplifier, not sure why is it so confidential if they are working from years on this!

It isn't out as a product yet, but very close. I think they are finalizing the production PCB - though maybe daniboun has a sample of the new amp already? Allo departed from the TI reference implementation, had some tricks around their inductors and seems to be trying to pursue parallel work on "soft" subjective sound quality as well as objective performance metrics. Here is a link to a thread where Johan posted a photo of the amp featuring the air core inductors:
https://www.diyaudio.com/forums/cla...iy-discussion-design-etc-328.html#post6440100

 

[conuss]

Do you think ALLO is smart enough to put the necessary capacitor for silent switching on?., Shui Yuan Audio was not smart enough! )))

 

[sychan]

Do you think ALLO is smart enough to put the necessary capacitor for silent switching on?., Shui Yuan Audio was not smart enough! )))

The Shui Yuan board is about $30 delivered from the other side of the world. When I get a pizza for the family from a place in town, it usually costs more than $30. Not including anti-pop on startup isn't dumb, it makes a lot of sense if you are competing on price!
I expect the Allo mono board could end up costing 10x the price of the Shui Yuan for 2 channels - the Allo Volt +D had a mute button to avoid pops at on and off. I would hope that for the price, they have built in anti-pop circuits.

 

[conuss]

The Shui Yuan board is about $30 delivered from the other side of the world. When I get a pizza for the family from a place in town, it usually costs more than $30. Not including anti-pop on startup isn't dumb, it makes a lot of sense if you are competing on price!
I expect the Allo mono board could end up costing 10x the price of the Shui Yuan for 2 channels - the Allo Volt +D had a mute button to avoid pops at on and off. I would hope that for the price, they have built in anti-pop circuits.

Based on your logic, the consumer should be happy with oversalted pizza, because it is much cheaper. But the increase in the equivalent cost of one capacitor is enough for the pizza to be edible enough.