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Advice needed: moving to class D

Bob21

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Hi everyone

I am on the hunt for a couple of class D amplifiers to replace a Sherwood RX-2030 and Sony TA-FE370, and to add some additional speakers to other rooms.

I apologise for my lack of understanding - I’ve done my best to read up as much as I can but I’ve reached the point where I think it would be better to just ask someone who knows! My only experience with Class D amps thus far has been with a tiny £6 TPA3116 unit that I had powering some Mission 750s. Apart from the fact that it had no bass/treble dials and only Bluetooth (no aux) I thought it wasn’t bad and sounded pretty good. The Mission 750s were small and not power hungry, and it seemed like a perfect combo. When my Sherwood amp died and I started on the hunt for a new amp, Class D seemed like the logical choice. I am looking to move entirely to class D just because of size and power saving.

The speakers I want to power range from the massive Goodmans Magister to the smaller Tannoy Eclipse. I might also be getting some B&Ws coming my way soon. Point being, I’m looking for something that will do these justice and not sound like a muffled bass-less foghorn. I started looking at the TPA3116 again, this time looking for something with bass and treble dials. I then came across the TPA3255 and also the MA12070.

I read through this thread: https://www.audiosciencereview.com/...-tpa3255-scientific-measurements-aside.25229/ and I don’t quite understand why there is a debate about swapping out the op amp?

And this one: https://www.audiosciencereview.com/...s-and-review-lm4562-and-opa2134-option.19155/ seems to suggest the Aiyima 07 is sloppy without a good PSU?

I was also looking at some of the reviews for the TPA3255 amps on AliExpress, namely this: https://a.aliexpress.com/_vEGlSC as it comes with its own internal PSU that is presumably fit for the job. But various people in the questions and reviews have said the unit is lacking bass and that the caps in the preamp need to be swapped out and other things changed. :-S

I’m afraid a lot of this goes over my head and gives me brain ache. Some say these are good, some not, some say the sound is rich, some say lacking unless you swap out caps and other stuff.

Can you recommend a good quality Class D amp that will do my Goodmans, Tannoy and B&W Speakers justice? A lot of the Aiyima products seem to have a pop when power is cut. That would probably irritate me so I’m looking for other manufacturers!

I am more than capable of soldering and swapping out components, so if there’s a suitable candidate that would sound amazing with some modifications, I’m all up for that. If anything I enjoy the challenge. Is buying these little amps and swapping out components standard practice? Or are there others that already have better designs? I can find negative reviews for just about any of the usual names you see on Amazon and AliEpxress… Nobsound, Fosi, Aiyima… they don’t seem to paint class D in a very good light. Any advice would be most welcome.

Thank you very much and my apologies again for my lack of understanding!
 

abdo123

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And this one: https://www.audiosciencereview.com/...s-and-review-lm4562-and-opa2134-option.19155/ seems to suggest the Aiyima 07 is sloppy without a good PSU?

I'm pretty sure the conclusion is the opposite, different PSUs and different OP amps made very little difference except in mains hum which is already not an audible concern even with the 'sloppy' PSU, @pma is free to chime in on this matter.

Eitherway, don't buy an actual sloppy PSU with Aiyima products, saving money at the expense of safety is a very foolish thing to do.
 
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Bob21

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Whoops, I hadn’t really got that far. I don’t really have a figure in mind. I could spend several hundred right now but I’m open to suggestions at different price points. If it’s really necessary to spend more I’ll spread it out. I suppose if it were to go much over £150-£200 per amp, I’d have to look at energy saving vs cost and all the Class AB amps that come up on Freecycle that would arguably sound very good. One thing I didn’t mention is that I don’t need Bluetooth or multiple inputs. I have network devices that I will plug into RCA, and use home automation to power up both devices at the same time.

I'm pretty sure the conclusion is the opposite, different PSUs and different OP amps made very little difference except in mains hum which is already not an audible concern even with the 'sloppy' PSU, @pma is free to chime in on this matter.

Eitherway, don't buy an actual sloppy PSU with Aiyima products, saving money at the expense of safety is a very foolish thing to do.

Understood thanks!
 
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Bob21

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To further the above, I guess some EQ stuff would be nice. One of the things that bothered me about the tiny £6 unit I mentioned above is that there was no bass and treble dials. More control is always a good thing. :)
 

mjcmt

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Can you recommend a good quality Class D amp that will do my Goodmans, Tannoy and B&W Speakers justice?
Here's 2 exceptional ones that will do your speakers justice and are on my short list for a move to class D:
Rogue Audio Sphinx v3
Marantz Model 30
 
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Bob21

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Here's 2 exceptional ones that will do your speakers justice and are on my short list for a move to class D:
Rogue Audio Sphinx v3
Marantz Model 30

Wow, those look nice. Those are wish list items for me but maybe over the course of a few months I could get 1 just for the living room. :)
 

LTig

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I wouldn't buy into tubes nowadays. There are too many disadvantages compared to solid state amplifiers (higher price, shorter longevity of tubes, very often much higher distortion).
 

fffffgggg54

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Marantz Model 30
Man this thing is a beauty. IMO tasteful styling compared to some of their other amps.
marantz_model30_black_render_f1.png

EQ stuff would be nice
Are you set on hardware EQ?
swapping out the op amp
AFAIk the OPA1656 op amps measure better than the NE5532 ones. The difference is negligible and performance should be limited by power supply noise among other things.
And this one: https://www.audiosciencereview.com/...s-and-review-lm4562-and-opa2134-option.19155/ seems to suggest the Aiyima 07 is sloppy without a good PSU?
Towards the end of the thread, there is mention of the Mean Well RS-100-24 SMPS power supply, 24V/4.5A. Tests seem to show that this is the best performing and most practical power supply.
I would steer clear of this unless you are willing to modify it. Looking at the design of the power connector and grounding scheme, it seems low quality and most certainly doesn't comply with grounding regulations.
1632673273672.png

The chassis appears to be left floating, and while I am no expert, I am pretty certain that there should be a connection between mains ground and the chassis, like so:
1632673587282.png
 
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Bob21

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Man this thing is a beauty. IMO tasteful styling compared to some of their other amps.
marantz_model30_black_render_f1.png


Are you set on hardware EQ?

AFAIk the OPA1656 op amps measure better than the NE5532 ones. The difference is negligible and performance should be limited by power supply noise among other things.

Towards the end of the thread, there is mention of the Mean Well RS-100-24 SMPS power supply, 24V/4.5A. Tests seem to show that this is the best performing and most practical power supply.

I would steer clear of this unless you are willing to modify it. Looking at the design of the power connector and grounding scheme, it seems low quality and most certainly doesn't comply with grounding regulations.
View attachment 155694
The chassis appears to be left floating, and while I am no expert, I am pretty certain that there should be a connection between mains ground and the chassis, like so:
View attachment 155698


Yeah I didn’t notice the grounding absence. I could easily change the IEC connector and add a ground to the chassis, I’ve done similar things before. I am a hobby tinkerer so changing components is no problem.

Thanks for the info on op amps. I didn’t quite understand it but you’ve cleared that up.

I’m not opposed to spending more on higher quality PSUs if required. No point doing things by half.

When you say hardware EQ, so you mean full EQ or including bass and treble dials too? I would probably say at the very least some bass and treble dials but I guess I am open to all and everything and will entertain most suggestions. My only experience of Class D has been that single TPA3116, so I’m relying on the knowledge and experience of others. I’m a bit of a magpie so a nice OLED screen isn’t needed but would look nice. I was looking at some of the SMSL stuff and that looked quite nice.
 

fffffgggg54

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When you say hardware EQ, so you mean full EQ or including bass and treble dials too?
I mean are you set on having bass and treble switches, or would you entertain the idea of using a digital parametric eq? Not sure if that would be an option though, as I am unsure of what sources you use. This would be possible if you use streaming services or have an offline music library. Not sure what you have before your amps, so can't say if this is a viable option for you.
 

VMAT4

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Check out this thread. Maybe you want to wait until it hits the USA market.
 
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Bob21

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I mean are you set on having bass and treble switches, or would you entertain the idea of using a digital parametric eq? Not sure if that would be an option though, as I am unsure of what sources you use. This would be possible if you use streaming services or have an offline music library. Not sure what you have before your amps, so can't say if this is a viable option for you.

I am using Acrylic devices before the amps and a locally networked collection + Spotify. AFAIK, Acrylic doesn’t have an EQ and Spotify doesn’t support the EQ via iOS when Spotify connect is used (how it connects to the Acrylic devices).

Check out this thread. Maybe you want to wait until it hits the USA market.

Sorry to be dumb, but how does this differ from other TPA3255 devices like the one I linked above at AliExpress? It looks good, though! :)
 

VMAT4

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I am using Acrylic devices before the amps and a locally networked collection + Spotify. AFAIK, Acrylic doesn’t have an EQ and Spotify doesn’t support the EQ via iOS when Spotify connect is used (how it connects to the Acrylic devices).



Sorry to be dumb, but how does this differ from other TPA3255 devices like the one I linked above at AliExpress? It looks good, though! :)
Well it will require some DIY skills. But most importantly it was reviewed here and measures well, verified by ASR.
 

Jdunk54nl

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Buckeye amps within budget?
 

Chrispy

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Buckeye amps within budget?

Think he's looking for integrated amps....
 

Jdunk54nl

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Think he's looking for integrated amps....
Not if his amps in the in the first post were the Aiyima A07 and the DIY boards and his second post saying he doesn't need bluetooth, multiple inputs, etc.
 

Chrispy

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Not if his amps in the in the first post were the Aiyima A07 and the DIY boards and his second post saying he doesn't need bluetooth, multiple inputs, etc.

Seems to be a mix looking back....

ps If I just see the word "amp" I think of only power amps.....not a receiver, not an integrated amp as so many do....
 
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JSmith

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I could spend several hundred right now but I’m open to suggestions at different price points. If it’s really necessary to spend more I’ll spread it out. I suppose if it were to go much over £150-£200 per amp



JSmith
 

Galliardist

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Man this thing is a beauty. IMO tasteful styling compared to some of their other amps.
marantz_model30_black_render_f1.png


Are you set on hardware EQ?

AFAIk the OPA1656 op amps measure better than the NE5532 ones. The difference is negligible and performance should be limited by power supply noise among other things.

Towards the end of the thread, there is mention of the Mean Well RS-100-24 SMPS power supply, 24V/4.5A. Tests seem to show that this is the best performing and most practical power supply.

I would steer clear of this unless you are willing to modify it. Looking at the design of the power connector and grounding scheme, it seems low quality and most certainly doesn't comply with grounding regulations.
View attachment 155694
The chassis appears to be left floating, and while I am no expert, I am pretty certain that there should be a connection between mains ground and the chassis, like so:
View attachment 155698
You don't necessarily need to worry about this. Marantz have been using floating ground with all their Class D amps going back to the PM-10 in 2017 and there are no reports I've seen in forums of problems resulting from it.

You should probably check for appropriate certification for your country (especially if considering some of the cheaper components out there) - but that's the case for any electrical item.
 
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