what D amp give best sound.

Hi All


I have the idea to learn some about class D amps, but there are a lot of different possibillitys, like sigma delta, self oscillation, pwm.

What of these topologies give the best sound? I did read a self osc feedbacked one is best, or maybe the sigma delta (sacd type) who has no feedback but a clock looks promissing.

I do analog amps like hybrids, but am a little curious about new stuff, and high resolution digital systems.

Thanks .

kees
 

amix

Member
2010-01-01 7:30 am
I can not really help you, since I do not have the experience required. But in German DIY audio forums there is a guy, Saarmichel, (he is also a member here, though, not very active), who has built a lot of Class-D amps (he built tube-amps before). He has put together a list of his subjective findings. You can find it over here. The only thing, that changed is, that he now has a new #1, which is being referenced here. Since you are from Holland I guess, that your German may be better than my Netherlandish ;-) I would especially recommend the last thread, I have mentioned. I take the freedom to quote and translate his list of Class-D amplifiers, he built:
1. Hypex UcD2K
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( Absolute Reference ).
2. Abletec ALC0300-1300
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( sound-quality wise very close to UcD2K ).
3. Hypex NC-400
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( Price / Performance-ratio ).
4. Abletec ALC1000-1300
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( extremley dynamic, might therefore lack long-term enjoyability on certain speakers ).
5. Connexelectronic CxD500 / SMPS600RE
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6. L-15/25D
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( only if speaker matches ).
7. Hypex UcD180 HG
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8. Connexelectronic IRS2092 (500 + 700 Watt Stereo-Module).
9. Connexelectronic Tripath TA3020 / SMPS1000A
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( unobtrusive ).
10. Hypex UcD400 HxR
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( never really could convinve me ).
11. Hifimediy T2
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( good, well-sounding and inexpensive entry-level amp )
99. Hifimediy T3S
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( absolutely not noteworthy ).
Now, there is a single change to the list: The Hypex UcD2K has been replaced by the Sure AA-AB32512. However, there is one caveat. People are uncertain as of it is really the AB32512. While this has been the module people ordered, it seems, that Sure is delivering the AA-AB32313 instead. The model-number on the mainboard implies this. He also mentioned, that in order to achieve the best sound, he had to use either his self-made PSU or the Meanwell HLG-320-36A. When he used a Meanwell HRP-600-48 the sound wasn't to his satisfaction. So, (his) dream-combo seems to be the Sure AA-AB32313 + Meanwell HLG-320-36A atm. That's the one I am going to use for an IA, I just need to settle on a pre-stage before that.

I am aware, that this list is not giving you the technical information, you asked for, but it may give some limited direction.
 
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Fo so far as I see, the fase shift self oscillating version give the best sound, needs some heavy calculation for the feedback poles.

But i have seen that the sigma delta 1 bit can do very well, I go sim both when time is present after ready the synergy horns.

Bus pumping for a half bridge is a issue, see that the reference one did wel with use a full bridge, so supply is less commanding.

Thanks for the nice info, now i can read something.

regards
 
Kees,
Good to see you over here in D land. I have been over in AB land as of late as I found that discrete transistor AB has very nice bass quality. Mids and highs the class D can compete very effectively for not much money if you don't need a lot of power. The list above is very Hypex UCD centric - great amps I have heard but pricey. Go try a $8 TPA3118 PBTL monoblock from Sanwu to get a sense. You will have lost almost nothing and can get an idea of low cost SOA 60w amp for pennies. Other ones to try are TDA7498, and IRS2092 circa 200W. I have all of these and the IRS has the lowest distortion but a hassle as it needs dual rail supply. If you are looking for something to power your Trynergy all you need is a TPA3118 PBTL to start things off. Get a $20 IRS2092 if you want to run the whole thing passively and drive a 3 way. If active try amp then qnty 3 of the TDA7498 will work nicely. Need some 24v 3A SMPS bricks to go with it.

But as you are familiar with class AB amps, I can also recommend the Apex FX8 or FH9 or JFET Circlophone. Even the basic Carlos Dx amp will work just fine as well for driving the Trynergy.
 
Hi X

The problem with bass when go class D is supply bus pumping, special with low frequenties, so going full bridge is the way to go, for me it is just a interest, because world changes, I have hybrid tube mosfet amp as you have heard already the music form it on youtube, a new oe who have total no feedback except mosfet source follower itselfs, but mosfet has high gm so no problem.

I have also sim a circlotron with tubes and mosfets, I have a bunch of amps designs, most are combinations of kwown idea.s

picture 1 is circlotron with tube/power jfets 2 is a local feedback allfet amp both never build.

but offtopic, these are liniair amps.

regards
 

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amix

Member
2010-01-01 7:30 am
Hi amix
I ordered a SURE AA AB32512, and received a AB32313.
Does Saarmichel feel that they give the same performance? Have you tried your yet?
Sorry for late answer.

I do not have the amp-module, as of yet. I got a good offer for two Anview ALC0300-1300 modules, and decided to build that before, and the AB32512 later. All I know is from reading the thread mentioned above.

What I can say is, yes, others, who ordered the AB32512, experienced the same! They asked Sure about it and Sure replied, that they are different amplifier modules with the same printing on the PCB (or something like that). People assume, that these amps are identical, except for the selection quality of the chips. So, if you order a AB32512, it seems, that you get an AB32313 with chips of higher quality selection. You may know this from the computer business, where they sell the same CPU under different model-names, for different prices, since some do not pass the high-stress tests, so they get sold as lower spec. But nobody knows for sure what Sure is doing there...

Nobody has mentioned any difference in performance. Therefore I guess, the only difference may be the stressability of the amp. Hence 400W vs. 500W.

Btw: Saarmichel is also a member on this forum here. You could PM him with further questions. Sorry, if I can not help you any further, but, as mentioned above, I decided to do another amp build before.
 
Amps with linear PSs using the hifimediy (EAT) T4 modules sound excellent with lots of power to 180W. I've sold five. About to try the T3 modules as monoblocks. Digikey IRS2092 250W reference, excellent but change the input cap to a real audio cap. Only a big linear PS will get the best from this one. Great sound, close to the T4 and better with some more congested music.
 
... Other ones to try are TDA7498, and IRS2092 circa 200W. I have all of these and the IRS has the lowest distortion but a hassle as it needs dual rail supply. If you are looking for something to power your Trynergy all you need is a TPA3118 PBTL to start things off. Get a $20 IRS2092 if you want to run the whole thing passively and drive a 3 way. If active try amp then qnty 3 of the TDA7498 will work nicely. Need some 24v 3A SMPS bricks to go with it.
Among the TDA7498-based boards, might this one https://it.aliexpress.com/item/TDA7..._1&btsid=f28d646d-b68d-4171-89e1-b4b52c4208e6 be recommended?

If yes, what power supply might be paired (how many Amperes)? In your opinion are further boards required (e.g. protection loudspeaker, soft start)?
many thanks
 
Personally I can recommend the old and the new EAT hifimediy T4 - 150W modules with speaker crowbar protection. The new ones, V1.3 may not be as warm as the original T4 but still very good. I have made and sold six T4s and are currently building a pair of T3 monoblocks with 44,000uf of Mundorf MLytic ultra low ESR filter caps.

I are also are using as my current amp a Digikey 250W IRS2092 based amp again with the high current 47,000uf Mundorf MLytic caps (two for a differential PS). Also I have built and sold amps with the Sure 100W modules and 500W module. Both OK but not as good as the T4s.
 
I are also are using as my current amp a Digikey 250W IRS2092 based amp again with the high current 47,000uf Mundorf MLytic caps (two for a differential PS). Also I have built and sold amps with the Sure 100W modules and 500W module. Both OK but not as good as the T4s.

To get the best sound out of my IRS2092 amps I found the chip's power supplies do need to be low impedance. The internal zeners have too high a dynamic impedance, external decoupling is called for - at least 470uF low ESR caps.
 
Personally I can recommend the old and the new EAT hifimediy T4 - 150W modules with speaker crowbar protection. The new ones, V1.3 may not be as warm as the original T4 but still very good. I have made and sold six T4s and are currently building a pair of T3 monoblocks with 44,000uf of Mundorf MLytic ultra low ESR filter caps.

I are also are using as my current amp a Digikey 250W IRS2092 based amp again with the high current 47,000uf Mundorf MLytic caps (two for a differential PS). Also I have built and sold amps with the Sure 100W modules and 500W module. Both OK but not as good as the T4s.
T3 and T4 are out of stock. Anyway for my active system I need at least 6 amps and 86 Euro x6 plus power supplies is not cheap. Finally the power is excessive for both tweeters and midrange. For this reason I continue to prefer the advice of X