TPA3251/55 High Power Class D Amplifiers

renaudrenaud · « **Reply #40 on:** 25 Dec 2017, 08:25 pm »

This is a picture with the 30V batt

And now the 50V:

and with the power lab

Sorry for the quality, it was with a smartphone.

flavo · « **Reply #41 on:** 17 Jan 2018, 12:46 am »

Quote from: TrungT 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.

Hello Trung, and anyone else that might like to help.
I just purchased the 3e-audio 3255. Should take a few weeks to show up and I'm wondering if I'm missing anything in the build or if I should add anything.
I have an enclosure with IEC, Meanwell 48v PS, RCA and speaker connectors. I need to order an on off switch. Is there a quality one anyone can recommend or any values I need to be aware of before I purchase one? In a best case scenario, what kind of wire would you recommend to do the internal wiring of the rca and speaker connectors?
Trung, what is that silver box attached to the IEC inside of your amp?

Thanks folks

Edited: As I found this info to an earlier question.

Quote from: rhing on 17 Dec 2017, 11:21 pm

I use 14ga PVC-insulated Copper wire from an IEC power cable to connect the power supply to the amp.

abongiov · « **Reply #42 on:** 17 Jan 2018, 11:00 am »

Flavo, that box is probably an IEM filter. I believe it used to filter your house power line, many of lights or smps for other material can create interference and this should help remove them. Sorry can't help for the cables as I have not build one myself, yet. Your list looks complete to me but I am a newbie.

To all others, between this TPA3251 and an Icepower ASX125, which onewould you suggest ?
It is about the same price, although the the ASX125 has power supply on board but the TPA3251EVM still needs one.

Thanks

flavo · « **Reply #43 on:** 17 Jan 2018, 03:06 pm »

Yes! IEC noise filter.
Trung sent me this link
https://www.schaffnerusa.com/technical-library/iec-inlet-filters/

cody69 · « **Reply #44 on:** 17 Jan 2018, 04:57 pm »

Quote

Flavo --
I just purchased the 3e-audio 3255. Should take a few weeks to show up and I'm wondering if I'm missing anything in the build or if I should add anything.

I am also interested in this. What are you using for volume control?
Are you using a volume pot -- or handling volume externally?

flavo · « **Reply #45 on:** 17 Jan 2018, 11:41 pm »

Quote from: cody69 on 17 Jan 2018, 04:57 pm

I am also interested in this. What are you using for volume control?
Are you using a volume pot -- or handling volume externally?

Externally. I currently have a DAC with Vol pot but will be getting a preamp to handle the pot and a different DAC.
Unfortunately I'm of no help in knowing what values you need for a Pot. Hopefully one of the experienced folks will be able to help you out.

wushuliu · « **Reply #46 on:** 18 Jan 2018, 05:37 pm »

Quote from: cody69 on 17 Jan 2018, 04:57 pm

I am also interested in this. What are you using for volume control?
Are you using a volume pot -- or handling volume externally?

The input impedance of the 3255 is IIRC ~24k. a 50k pot or lower is recommended, with lower being better. This is a generalization, YMMV.

wushuliu · « **Reply #47 on:** 18 Jan 2018, 05:45 pm »

Quote from: flavo on 17 Jan 2018, 11:41 pm

Externally. I currently have a DAC with Vol pot but will be getting a preamp to handle the pot and a different DAC.
Unfortunately I'm of no help in knowing what values you need for a Pot. Hopefully one of the experienced folks will be able to help you out.

Hi flavo, if you are putting an on/off switch from the Meanwell output then you can use whatever switch you want since the voltage will be pretty low at <50v. If you use a switch at the mains input you will of course want a switch rated for at or above your mains voltage of 120 or 220.

Wiring is up to you. My only recommendation is to have the power supply wiring be a healthy gauge. I like 16 or 14awg, but that's just my preference. I use silicone tinned 'racing' wire because it's cheap, withstands very high voltage and comes in large gauges and subjectively to me sounds decent (when used as speaker wire).

envydd · « **Reply #48 on:** 1 Feb 2018, 01:57 am »

Quote from: drphoto 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)

If you wait for 1 yr, you will see SMSL stick a DAC and a PSU with a LCD panel for around 500. Check out SMSL A8 with ice power.

wushuliu · « **Reply #49 on:** 1 Feb 2018, 05:22 am »

https://www.ebay.com/itm/FXAUDIO-FX502SPRO-TPA3250-Class-D-Digital-Amplifier-Hi-Fi-Stereo-Audio-Power-Amp-/253284553008

flavo · « **Reply #50 on:** 15 Feb 2018, 11:09 pm »

Everything is in except a fuse and holder. I didnt think to order one and googling doesn't seem to be helping me.
How do I know what size fuse to install for the 3255 with the Meanwell 48V PS?
The specs on the Meanwell are --350.4W 48V 7.3A 115Vac or 230Vac

So my guess would be a 10A 250V fuse?
If that's correct. Do I want a slow blow? Does it matter if it's 5x20 or 6.3x30 and lastly, does anyone have a suggestion on a inline fuse holder? I was thinking it would be easier to find a audio quality one but that's proven difficult as well.
Thanks so much.

wushuliu · « **Reply #51 on:** 15 Feb 2018, 11:12 pm »

Quote from: flavo on 15 Feb 2018, 11:09 pm

Everything is in except a fuse and holder. I didnt think to order one and googling doesn't seem to be helping me.
How do I know what size fuse to install for the 3255 with the Meanwell 48V PS?
The specs on the Meanwell are --350.4W 48V 7.3A 115Vac or 230Vac

So my guess would be a 10A 250V fuse?
If that's correct. Do I want a slow blow? Does it matter if it's 5x20 or 6.3x30 and lastly, does anyone have a suggestion on a inline fuse holder? I was thinking it would be easier to find a audio quality one but that's proven difficult as well.
Thanks so much.

? Doesn't the mean well have an internal fuse?

flavo · « **Reply #52 on:** 15 Feb 2018, 11:41 pm »

Just did a google image search and the meanwell does indeed have a fuse inside of it.
Thank you. I'll be sure to post some pics when I'm done.

goggle1824 · « **Reply #53 on:** 12 Mar 2018, 12:25 pm »

Following, reading, trying to digest and learn.

emac · « **Reply #54 on:** 23 May 2018, 12:46 pm »

Quote from: wushuliu on 1 Feb 2018, 05:22 am

https://www.ebay.com/itm/FXAUDIO-FX502SPRO-TPA3250-Class-D-Digital-Amplifier-Hi-Fi-Stereo-Audio-Power-Amp-/253284553008

Ordered one of these amps from China (though from a different seller since the one listed in the link sent me a star ornament rather than the amp itself. At least I got refunded). And I have to say that I'm impressed. It replaced a Fleawatt w/ Astron power supply that I'd been using in my system with a ModWright Oppo BD-105 and GR Research Diluceos. More detail and more punch (probably because it is more powerful). But the nice thing about the amp is that you can play with the opamps. I initially put in opa2227's, which improved the separation as well as musically. Now that I've gotten some opa627's, which probably are my favorite opamp musically, this is really turning into a nice amp for about $100. Cheap and cheerful. Can't go wrong.

wushuliu · « **Reply #55 on:** 23 May 2018, 05:38 pm »

Quote from: emac on 23 May 2018, 12:46 pm

Ordered one of these amps from China (though from a different seller since the one listed in the link sent me a star ornament rather than the amp itself. At least I got refunded). And I have to say that I'm impressed. It replaced a Fleawatt w/ Astron power supply that I'd been using in my system with a ModWright Oppo BD-105 and GR Research Diluceos. More detail and more punch (probably because it is more powerful). But the nice thing about the amp is that you can play with the opamps. I initially put in opa2227's, which improved the separation as well as musically. Now that I've gotten some opa627's, which probably are my favorite opamp musically, this is really turning into a nice amp for about $100. Cheap and cheerful. Can't go wrong.

Thanks for the review. Especially about the opamps. I hadn't thought about whether different opamps might affect sound for these TPA32XX amps (too busy being impressed by what I heard). So this opens up a whole new avenue for exploration.

emac · « **Reply #56 on:** 23 May 2018, 06:21 pm »

Quote from: wushuliu on 23 May 2018, 05:38 pm

Thanks for the review. Especially about the opamps. I hadn't thought about whether different opamps might affect sound for these TPA32XX amps (too busy being impressed by what I heard). So this opens up a whole new avenue for exploration.

Given that it's been at least 8 years since I've thought much about opamps, any suggestions about others to try? I'd played around with a bunch in the past and had settled on the opa627's in my Maverick DAC, but I'm sure that there are better things out now.

Also, before I forget, if one is going to put opa627's in this amp, they need to be dual SOIC to DIP8. The DIP to DIP ones won't fit.

wushuliu · « **Reply #57 on:** 23 May 2018, 06:34 pm »

Quote from: emac on 23 May 2018, 06:21 pm

Given that it's been at least 8 years since I've thought much about opamps, any suggestions about others to try? I'd played around with a bunch in the past and had settled on the opa627's in my Maverick DAC, but I'm sure that there are better things out now.

Also, before I forget, if one is going to put opa627's in this amp, they need to be dual SOIC to DIP8. The DIP to DIP ones won't fit.

Class D operation is way above my pay grade. I think the opamps are just buffers for single ended input to differential conversion. In this context your guess is as good as mine.

Oscillate · « **Reply #58 on:** 17 Jun 2018, 01:22 pm »

Can the TPA3251/55 boards be setup for balanced XLR inputs?

I have a Class D Audio SDS470 4-channel amplifier. I was wondering
about using it's case, toroidal transformer and power supply and just
swapping in 2 of these boards? ...is that possible? ...practical and safe?

Thanks for any replies in advance

mboxler · « **Reply #59 on:** 17 Jun 2018, 03:05 pm »

Quote from: Oscillate on 17 Jun 2018, 01:22 pm

Can the TPA3251/55 boards be setup for balanced XLR inputs?

I have a Class D Audio SDS470 4-channel amplifier. I was wondering
about using it's case, toroidal transformer and power supply and just
swapping in 2 of these boards? ...is that possible? ...practical and safe?

Thanks for any replies in advance

If you are referring to the EVM's, they can be configured to accept differential inputs. However, the inverted and non-inverted signal will each pass through it's own amplifier to a BTL output.

These are signal supply amplifiers. If you use the ClassDAudio power supply, make sure you connect it right!

Mike