TPA3251/55 High Power Class D Amplifiers

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wushuliu

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TPA3251/55 High Power Class D Amplifiers
« on: 25 Sep 2017, 07:28 pm »
Time and technology marches on. For the low power TPA311X lovers out there who are looking for step up in sound quality or for those who need more power before jumping on board, the newer TPA32XX boards are now easily available. I've been using a TPA3251D2 (140W) from 3eaudio



http://www.3e-audio.com/amplifier/tpa3251-2ch-140w/
http://www.ebay.com/itm/TPA3251-2x140-Watt-1-THD-N-Class-D-Audio-Amplifier-/332371653319?hash=item4d62e4f2c7:g:LHEAAOSwlY1ZNqix

The TPA3251 is optimized for 4ohms, TPA3255 for 8ohms.

Texas Instruments themselves appear to now be competing aggressively with the diy market. They have now offered a 50% discount on their evaluation boards if you register with them and use code 'highpoweraudio' on checkout.

How do they sound? Compared to the very tricked out, wonderfully made Wiener Mono TPA3118 boards I had, the TPA3251 to me is even quieter and even better low level detail and overall realism. This amp has been one of the most rewarding purchases of the past few years. I haven't even modded the damn thing! No desire to. Toss those YJ boards and get one of these.

Is there a catch? Yes, in that TPA311X prices have dropped so low you can get them for just a few bucks now. And being low power the power supply needs are more flexible. The higher power TPAs will cost you around a whopping $90+ (less if you get the TI discount). Of course that's nothing in audio terms, but the power supply will also cost about the same depending. I use a Connexelectonic SMPS that cost about $85. So total cost will be in the <$200 range. Not bad for for the watts you get and the sound quality. Gorgeous sound quality.

I can't recommend these enough. Crazy to think how far Class D has come in 10 years.


Wind Chaser

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #1 on: 25 Sep 2017, 07:55 pm »
Crazy to think how far Class D has come in 10 years.

I was thinking the same thing the other day

Long story short, a TPA-3116 displaced a very highly regarded SET in my system. As nice as the SET was, it wasn't up to the task of dealing with the difficult load the Spatial M3ts presents. The 3116 performed much better. In fact the person who bought my SET was flat out astonished how good the cheap TI board sounded with the Spatial OBs.


randytsuch

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #2 on: 25 Sep 2017, 09:43 pm »
There's a thread at diyaudio on the ti eval units.

Looks interesting, but the 3255's are oos :(

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #3 on: 25 Sep 2017, 09:52 pm »
There's a thread at diyaudio on the ti eval units.

Looks interesting, but the 3255's are oos :(

Out of stock at TI, But 3e-audio have them in stock. They cost $25 more than the TI's discounted boards, but I think they look nicer and they a little measure better than the TI. Very nice boards, real solid feel to them.

randytsuch

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #4 on: 25 Sep 2017, 10:33 pm »
Out of stock at TI, But 3e-audio have them in stock. They cost $25 more than the TI's discounted boards, but I think they look nicer and they a little measure better than the TI. Very nice boards, real solid feel to them.

Curious what op amps 3e is using?  In the ti board, it uses op amps to generate a balanced signal to the amp chip from a single ended input.
Since my dac is single ended, would be using the op amp.

Randy

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #5 on: 25 Sep 2017, 11:54 pm »
Curious what op amps 3e is using?  In the ti board, it uses op amps to generate a balanced signal to the amp chip from a single ended input.
Since my dac is single ended, would be using the op amp.

Randy

JRC4580

WC

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #6 on: 26 Sep 2017, 01:47 am »
The TI eval board for the 3255 allows for a single channel output of around 600A. I thought it could make a good sub amp. The 3e-audio board doesn't seem to have that ability.

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #7 on: 26 Sep 2017, 02:05 am »
The TI eval board for the 3255 allows for a single channel output of around 600A. I thought it could make a good sub amp. The 3e-audio board doesn't seem to have that ability.

Yes, the 3e-audio are for 2 channel only. IIRC the TPA32XX do not perform as optimally in mono. Not to mention it would be kind of a waste to use amps that sound this good just for subs. Plenty of other options for that.

srb

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #8 on: 26 Sep 2017, 02:17 am »
The TI eval board for the 3255 allows for a single channel output of around 600A.

600A (amps) would be enough to completely melt the driver and anything in it's vicinity!  600W is the max 2Ω mono output.  Of course, that figure is with 10% THD+N, which is fairly high even for a subwoofer application, and 480W is the mono 2Ω output at 1% THD+N.

wushuliu, I see you're using an SMPS with your TI module.  I've noticed that with manufactured Class D amps including the Class D manufacturers on this forum, the field seems to be split between SMPS and Linear supplies, and the linear supplied amps actually seem to be more prevalent among the smaller boutique manufacturers.

I'm sure you've experimented quite a bit with both and have you come to a definitive preference or has it varied with each Class D module?

Steve

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #9 on: 26 Sep 2017, 02:37 am »
600A (amps) would be enough to completely melt the driver and anything in it's vicinity!  600W is the max 2Ω mono output.  Of course, that figure is with 10% THD+N, which is fairly high even for a subwoofer application, and 480W is the mono 2Ω output at 1% THD+N.

wushuliu, I see you're using an SMPS with your TI module.  I've noticed that with manufactured Class D amps including the Class D manufacturers on this forum, the field seems to be split between SMPS and Linear supplies, and the linear supplied amps actually seem to be more prevalent among the smaller boutique manufacturers.

I'm sure you've experimented quite a bit with both and have you come to a definitive preference or has it varied with each Class D module?

Steve

Hi Steve, it's been a while since I've used a linear PS for a higher power amp. Not since the Classdaudio days. Back then I was impressed with the Connex SMPS, but IIRC the linear allowed more low end oomph if you went big enough. Convenience wins this time around - a massive toroid and a huge cap bank (and enclosure, etc etc.) just seems like a chore. The Connex sounds wonderful. No drawbacks come to mind. No edginess or this or that. A beefy linear is probably better, but as is it sounds too good to care. First amp set up I have left alone maybe ever.

elb

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #10 on: 26 Sep 2017, 09:06 am »

Hi wushului, How would rate this amplifier compared to a Classdaudio SDS254?

I see that 3eaudio also have a SMPS.



JohnR

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #11 on: 26 Sep 2017, 10:47 am »
An actual heatsink!

Thanks wushuliu  :thumb:

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #12 on: 26 Sep 2017, 12:34 pm »
Hi wushului, How would rate this amplifier compared to a Classdaudio SDS254?

I see that 3eaudio also have a SMPS.

Been a while since the CDA but this should definitely be an upgrade. Certainly these have lower distortion and noise iirc. It's another league imo.

@johnr. Lol. Big one. Barely gets warm.

drphoto

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #13 on: 27 Sep 2017, 01:15 am »
Are these available in a ready made amp? I love DIY audio and enjoy building, but have almost zero free time these days......well a few hours to do crap like post on forums, but not enough to source component and build an amp I have a lepai 2020A powering my Merlin monitors in my computer monitor setup. Clearly an amp upgrade would help. Lepai is a decent dirt cheap little amp and I'm impressed it can even power these speakers. but it makes me want more. (decided upgraded PS not worth time or money)

wushuliu

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #14 on: 27 Sep 2017, 01:38 am »
Are these available in a ready made amp? I love DIY audio and enjoy building, but have almost zero free time these days......well a few hours to do crap like post on forums, but not enough to source component and build an amp I have a lepai 2020A powering my Merlin monitors in my computer monitor setup. Clearly an amp upgrade would help. Lepai is a decent dirt cheap little amp and I'm impressed it can even power these speakers. but it makes me want more. (decided upgraded PS not worth time or money)

No ready made amps I'm aware of. 3eaudio sells their own SMPS and they provide wiring and connectors for the boards so all you'd need to worry about is the mounting/enclosure part.


brother love

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #15 on: 27 Sep 2017, 10:50 am »
Here is an image from the 3e audio website showing the power supply connected w/ an umbilical cord to the TPA3255 amp board  http://www.3e-audio.com/amplifier/tpa3255-2ch-260w/

So are all the connectors provided w/ the amp board & power supply? (3e audio website & their ebay listings do not specify or show separate accessories). With that short umbilical cord, I assume both boards should fit in the same enclosure, or no (maybe make longer umbilical cord if needed)? Any good enclosure recommendations? (found some single board clear plastic ones on fleabay, but curious of better options).  Thanks wushuliu!



Yatsushiro

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #16 on: 27 Sep 2017, 11:50 am »
So are all the connectors provided w/ the amp board & power supply? (3e audio website & their ebay listings do not specify or show separate accessories).

A full set of connectors and wire tails are supplied with the amplifier board. With the power supply comes a longer umbilical than shown, and an AC connector with wire tails.

There is a large variety of chassis/enclosures available from either ebay or AliExpress (https://www.aliexpress.com/af/amplifier-chassis.html?SearchText=amplifier+chassis&ltype=wholesale&d=y&tc=main&blanktest=0&initiative_id=SB_20170927034752&origin=n&catId=0&isViewCP=y)

fredgarvin

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Re: TPA3251/55 High Power Class D Amplifiers
« Reply #17 on: 27 Sep 2017, 03:17 pm »
A full set of connectors and wire tails are supplied with the amplifier board. With the power supply comes a longer umbilical than shown, and an AC connector with wire tails.

There is a large variety of chassis/enclosures available from either ebay or AliExpress (https://www.aliexpress.com/af/amplifier-chassis.html?SearchText=amplifier+chassis&ltype=wholesale&d=y&tc=main&blanktest=0&initiative_id=SB_20170927034752&origin=n&catId=0&isViewCP=y)

That just makes a guy want to pick one up, if it's that easy. I don't need that much power for my speakers though. The main drawback to the classD boards is that it's hard to find one with more than one input. I suppose an input switcher works but I wonder about signal purity.

brother love

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #18 on: 27 Sep 2017, 05:36 pm »
Thanks Yatsushiro.  8)

TrungT

Re: TPA3251/55 High Power Class D Amplifiers
« Reply #19 on: 26 Oct 2017, 11:57 pm »
Have been listening the amp for couple weeks, sound very good with the Cornwall and it's quiet.
It's a top SS amp does well with the Cornwall.

Tested on 4 Ohms speaker, it did not sound right for some reason, only listened for few minutes.
Thanks Wushuliu.  :thumb: