MA12070 vs TPA3255 (Scientific Measurements Aside)

[Joe Smith]

Please let me know if/when you hear from him and what the stock replenishment status is, thanks.

I was told early September, like after Labor Day, he will have more of those in stock (dip8 base).

 

[DACslut]

I appreciate science, don't get me wrong. Which is exactly why I'm fully vaccinated. My original post states "(Scientific Measurements Aside)" and wasn't meant to get the "Technical Experts" riled up.

We could argue "science, politics and religion" for an eternity. I'm through with commenting about whether "this or that" is crap or fantasy. Thanks for your opinions and have a great day.

 

[JohnYang1997]

I took issue with his "Opamp rolling is a sucker's game, at best will not actually improve anything sonic, and can very much make things worse." comment. You could argue pretty much the whole audiophile scene is a sucker's game if that's the case. That's kind of like saying interconnects, speaker wire and power cord preferences, etc., is a sucker's game. Oh, I almost forgot the "Burn-In" mythology, lol.

Without going into most details. Yes, the whole audiophile scene is mostly sucker's game or had been. It's getting better now because site like this exists. Surely even in here we often see claims without evidence or proven false. It's one thing to say what it is, it's another to contribute to this and help make things better that's for sure.

Back to the details, tube circuits mostly are designed by designers who do not believe in transistor circuits or high performance circuits. So by quantity most tube circuits perform very badly. It's at the level so bad changing tube can actually significantly alter output. So that's that.

Changing opamp willynilly is just asking for trouble. Some diyers who know a bit better can swap opamps but they almost all suffer from bias due to sighted listening. It's very evident that just the model number can affect how you hear things in the brain. And the difference vanishes in blind tests.

Burn in exists in component level objectively. Everything ages. However good designs and most majority of designs can live with the variances and still produce consistent outputs.

Idk how it became to this. It seems to be a bit off topic. So I won't be commenting on this further. Thanks.

 

[SIY]

I appreciate science, don't get me wrong. Which is exactly why I'm fully vaccinated. My original post states "(Scientific Measurements Aside)" and wasn't meant to get the "Technical Experts" riled up.

We could argue "science, politics and religion" for an eternity. I'm through with commenting about whether "this or that" is crap or fantasy. Thanks for your opinions and have a great day.

I hope you understand this is a science forum. Yes, measurements, but also controlled listening (no peeking, level matched). Unlikely claims unsupported by either measurement, ears-only listening, or both will be treated with the same respect as similar claims of alien abductions with anal probing.

 

[DACslut]

I have a question for any "Technical Expert" (no sarcasm here) who feels like answering about why I haven't seen a TPA3255 amp, DIY or finished, that safely goes down to a 2 ohm output? Forgive me if one does exist, I just haven't found one yet. I know there's a boatload of other class D chip amps rated for that kind of load. There's also at least a few MA1270 finished amps, namely the Sabaj A20a, S.M.S.L DA-9 and AO200, that have the 2 ohm rating specification. I plan on connecting in a parallel configuration my two sets of Sony SS-CS5's to the AO200 (awesome amp BTW) and not worry about the lowered impedance load. JohnYang1997 indicated in an earlier comment that the TPA3255 and pretty much any Class D chip inherently have the 2 ohm output capability, so what gives? Thanks.

 

[JohnYang1997]

I have a question for any "Technical Expert" (no sarcasm here) who feels like answering about why I haven't seen a TPA3255 amp, DIY or finished, that safely goes down to a 2 ohm output? Forgive me if one does exist, I just haven't found one yet. I know there's a boatload of other class D chip amps rated for that kind of load. There's also at least a few MA1270 finished amps, namely the S.M.S.L DA-9 & AO200, that have the 2 ohm rating specification. I plan on connecting in a parallel configuration my two sets of Sony SS-CS5's to the AO200 (awesome amp BTW) and not worry about the lowered impedance load. JohnYang1997 indicated in an earlier comment that the TPA3255 and pretty much any Class D chip inherently have the 2 ohm output capability, so what gives? Thanks.

There are two main reasons TPA3255 amps have potential issue when driving 2ohm speakers.

1, There are output filters that consist of complex impedance. If there's no PFFB, the high frequency roll off for 2ohm loads will be too big if the filters are designed for 4-8ohm load. A filter designed for 2ohm load can work. PFFB can work.
MA12070 does not need filter because it's 5 level output design. So no frequency response variance with different loads.

2, 2ohm load requires more current and less voltage. When tpa3255 running at 48V or 51V there maybe issue with safe operating area issue with its output stage. A carefully designed and tested current limiting threshold and lower supply voltage can help. Heat dissipation needs to be taken care of too.
MA12070 has only 26V rail. It's easier to handle 2ohm load at this low voltage. And MA12070 has higher efficiency both thanks to multi level design and SiC output. So MA12070 is born with benefits of driving lower impedance loads

Running lower supply voltages, setting more aggressive current limit, redesign the output filter and/or incorporate PFFB should make TPA3255 suitable for 2ohm load.

 

[Clayton_78]

I have a question for any "Technical Expert" (no sarcasm here) who feels like answering about why I haven't seen a TPA3255 amp, DIY or finished, that safely goes down to a 2 ohm output? Forgive me if one does exist, I just haven't found one yet. I know there's a boatload of other class D chip amps rated for that kind of load. There's also at least a few MA1270 finished amps, namely the Sabaj A20a, S.M.S.L DA-9 and AO200, that have the 2 ohm rating specification. I plan on connecting in a parallel configuration my two sets of Sony SS-CS5's to the AO200 (awesome amp BTW) and not worry about the lowered impedance load. JohnYang1997 indicated in an earlier comment that the TPA3255 and pretty much any Class D chip inherently have the 2 ohm output capability, so what gives? Thanks.

Probably because of poor choice of peripheral components to CI TPA3255, as a friend in another post mentioned, for example, the inductors.
When those of mine arrive, if you like I can test it with a resistive load at 2ohms.

Greetings

 

[DACslut]

There are two main reasons TPA3255 amps have potential issue when driving 2ohm speakers.

1, There are output filters that consist of complex impedance. If there's no PFFB, the high frequency roll off for 2ohm loads will be too big if the filters are designed for 4-8ohm load. A filter designed for 2ohm load can work. PFFB can work.
MA12070 does not need filter because it's 5 level output design. So no frequency response variance with different loads.

2, 2ohm load requires more current and less voltage. When tpa3255 running at 48V or 51V there maybe issue with safe operating area issue with its output stage. A carefully designed and tested current limiting threshold and lower supply voltage can help. Heat dissipation needs to be taken care of too.
MA12070 has only 26V rail. It's easier to handle 2ohm load at this low voltage. And MA12070 has higher efficiency both thanks to multi level design and SiC output. So MA12070 is born with benefits of driving lower impedance loads

Running lower supply voltages, setting more aggressive current limit, redesign the output filter and/or incorporate PFFB should make TPA3255 suitable for 2ohm load.

Thanks for the kind reply. Most of your explanation is over my head but I trust your expertise for sure. So essentially what you're saying is the TPA3255 is quite capable of outputting to 2 ohm loads. However, the design challenges to achieve this capability doesn't qualify the end result in a practical sense? That would explain the non-existence of the amp in question?

 

[DACslut]

Probably because of poor choice of peripheral components to CI TPA3255, as a friend in another post mentioned, for example, the inductors.
When those of mine arrive, if you like I can test it with a resistive load at 2ohms.

Greetings

That would be cool, thanks for the offer.

 

[JohnYang1997]

Thanks for the kind reply. Most of your explanation is over my head but I trust your expertise for sure. So essentially what you're saying is the TPA3255 is quite capable of outputting to 2 ohm loads. However, the design challenges to achieve this capability doesn't qualify the end result in a practical sense? That would explain the non-existence of the amp in question?

Basically. I'm not 100% sure what you mean by the design challenges doesn't qualify the end result. Most designs are derived from Ti reference design. It really takes some effort to make this work. However it can be done and will be done in the future.

 

[SIY]

Thanks for the kind reply. Most of your explanation is over my head but I trust your expertise for sure. So essentially what you're saying is the TPA3255 is quite capable of outputting to 2 ohm loads. However, the design challenges to achieve this capability doesn't qualify the end result in a practical sense? That would explain the non-existence of the amp in question?

There’s always the commercial end of it as well. For home audio, any extra expense to drive unusual and rare loads without compromising performance into more common loads is not worth it. For car audio, the calculus may be different.

Sorry to be terse, but I’m packing up my lab and house for a cross country move, so time is rather short.

 

[DACslut]

There’s always the commercial end of it as well. For home audio, any extra expense to drive unusual and rare loads without compromising performance into more common loads is not worth it. For car audio, the calculus may be different.

Sorry to be terse, but I’m packing up my lab and house for a cross country move, so time is rather short.

Hopefully far, far away from the AZ "fry an egg" heat, wildfires, monsoons and flash flooding. Good luck and be safe.

 

[DACslut]

Basically. I'm not 100% sure what you mean by the design challenges doesn't qualify the end result. Most designs are derived from Ti reference design. It really takes some effort to make this work. However it can be done and will be done in the future.

Ya, I have a goofy way of explaining myself sometimes, sorry. You basically interpreted my question correctly. I'm looking forwad to the "However it can be done and will be done in the future." statement coming to fruition soon, hopefully sooner rather than later.

 

[SIY]

Hopefully far, far away from the AZ "fry an egg" heat, wildfires, monsoons and flash flooding. Good luck and be safe.

Gracias. This was the coolest July ever here, which means just roasting.

 

[Ralferator]

All that stuff kind of explains why S.M.S.L's engineers decided to incorporate a "soft clipping" setting with their new dual MA12070 designs? They seem to be overwhelmingly well received by their respective owners. I did notice a few grumblings about the DA-9's build quality and it's display locking. I'm not sure if I'm gonna keep the Sabaj A10a now that I've got the S.M.S.L AO200.

On another note, why would anyone spend more money on a budget-friendly but inferior, basic amp when an opamp upgraded AIYIMA A07 is all you need? The Volt+ D (Double) 2x60W amp comes to mind. I chose to add to my audio arsenal with the AO200 because of it's many useful features and positive vibes it's DA-9 cousin is receiving from several audiophile circles. However, I will NEVER give up my A07 unless someone threatens my life and even then I would probably hesitate.

I think if somemone threatens my life i would give them my TPA3255 amp and buy another one for 70$. But i agree that those amps are awesome. I just don't think the OP amps need to be upgraded, because the tiny differences in measurements most likely don't make a difference in sound.

 

[Clayton_78]

I think if somemone threatens my life i would give them my TPA3255 amp and buy another one for 70$. But i agree that those amps are awesome. I just don't think the OP amps need to be upgraded, because the tiny differences in measurements most likely don't make a difference in sound.

which TPA3255 amplifier do you use?
You are Brazilian, aren't you?
If so, we can exchange some ideas!
I use 3e Audio and a couple of monoblocks that I set up. I'm enjoying it too much.

Greetings.

 

[AudioArchitech]

AYIMA released a newer model called the A08. It's basically an A07 with a 36V 9.5A power supply built in, no need to purchase a Meanwell psu... I have one, it's fairly good. I thought about swapping OP amps but the DIY TPA3255 community convinced me that it makes no difference in this amp design so I left it stock. I primarily use it in system 2 setup but have I used it on my main setup as well to compare and test... Switching between my Audiolab 6000A and the A08 there are some differences in sound, overall tonality, bass.... The A08 is pretty good, but when listening to higher quality, Tidal...the Audiolab is definitely better. If listening to Spotify, I almost prefer the A08 in some ways, the (lower resolution) highs are more pleasant. but mid bass sounds a bit more "digital?" When using Audiolab and Spotify, I actually tweak EQ using Equalizer APO and roll of the highs a bit. All this through a E30 DAC. It would be interesting to try a different dac with the A08 and compare against the 6000A/E30 combo. Something like a D30 Pro, D70s, DO200 or maybe a Schiit...

 

[SIY]

Switching between my Audiolab 6000A and the A08 there are some differences in sound, overall tonality, bass.... The A08 is pretty good, but when listening to higher quality, Tidal...the Audiolab is definitely better. If listening to Spotify, I almost prefer the A08 in some ways, the (lower resolution) highs are more pleasant. but mid bass sounds a bit more "digital?"

Could you describe the controls you used to determine this?

 

[AudioArchitech]

Controls to switch between A08 and Audiolab 6000A? Set volume levels on both amps using a pro SPL meter. Play some music, pause, power down and swap amps (banana plugs) Restart the same music. It's pretty obvious, don't need a switcher...

I will add that with vocals, the A08 is pretty good, has a good "live" feeling sound to it. I'm surprised how close it is to the Audiolab 6000A, Audiolab still wins but the A08 is not far behind.

 

[SIY]

Controls to switch between A08 and Audiolab 6000A? Set volume levels on both amps using a pro SPL meter. Play some music, pause, power down and swap amps (banana plugs) Restart the same music. It's pretty obvious, don't need a switcher...

The problem is inaccurate level matching and no attempt to do ears-only. Seriously, you have to do basic controls for stuff like this.