Sure Electronics 2 x 250 watt Class D Amplifier

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I bought one of these from Sure Electronics on ebay for roughly 50 US dollars shipped.

It arrived today, i gave it a quick test and it seem to work like it should and sounds fairly decent. I run it off 2x60VDC and use two 4 ohm speakers.

My biggest gripe with it so far are the nasty unknown brand cheap chinese electrolytics which i do not trust one bit!

A few pics and a video: Sure Electronics 2x250W Class D amplifier test - YouTube
 

Attachments

  • NHlDB.jpg
    NHlDB.jpg
    703.4 KB · Views: 1,173
  • 1TeKl.jpg
    1TeKl.jpg
    643.8 KB · Views: 1,114
  • pBxdp.jpg
    pBxdp.jpg
    677.4 KB · Views: 1,056
Really 2x 250 watts? Unlikely that heat sink could deal with a 1/4 of that.
Good thing the power claim is BS :)
Video is too dark to see anything.. No need to mention listening to Audio 'performance' amateur recorded / uploaded to Utube :rolleyes:
then replayed thru my 'puter setup tells one Nothing about the performance beyond that it is indeed making sounds.
 
Actually that heatsink could prolly handle a 2x500W amp, or even a 2x1000W amp using a fan as its class D switchmode rather than analog class AB.

Class d amplifiers have much higher efficiency than class AB = alot less heat.

And to be honest, it really does sound exactly the same in the video as in real life, also youtube does not compress the audio unless you watch the video with the 240p mode, if 360p or higher, the audio is the actual raw unaltered audio from the original video file.

If you think it sounds bad, thats what the amp actually sounds like, so if u dont like the sound in the vid, then don't buy this amp.
 
Last edited:
I've ran this amp for around 30 minutes now at normal listening levels and the heatsink is getting alarmingly hot!!

I'm expecting the amp to explode any minute now, so i cannot recommend this amp to anyone, i rather discourage anyone from buying it.

Do not buy the fanless class d amps from sure electronics, they get dangerously hot!!!
 
I've ran this amp for around 30 minutes now at normal listening levels and the heatsink is getting alarmingly hot!!

I'm expecting the amp to explode any minute now, so i cannot recommend this amp to anyone, i rather discourage anyone from buying it.

Do not buy the fanless class d amps from sure electronics, they get dangerously hot!!!

Ha-Ha,Don't be discouraged,You get what you pay for i think~
Maybe you can refer to my design,Class D is very compact,i use a smaller heatsink,Don't worry if The temperature is not higher than 70 degrees in normal work~~

http://www.diyaudio.com/forums/clas...ass-d-amplifier-lets-make-class-d-easier.html
 
I've now ran this amp for a bit more, this time on a 8 ohm load rather than 4 ohm, after about a hour, the amp started making ticking noises, like if some protection circuit was starting to kick in, then i noticed the output industors were smelling like a overheated transformer, yes they are blistering hot.

This amplifier is clearly not properly made, even one of the blue LEDs on the board is shifting color like its beeing overdriven.

I've came to the conclusion that this amplifier was a complete waste of money.
 
I've now ran this amp for a bit more, this time on a 8 ohm load rather than 4 ohm, after about a hour, the amp started making ticking noises, like if some protection circuit was starting to kick in, then i noticed the output industors were smelling like a overheated transformer, yes they are blistering hot.

This amplifier is clearly not properly made, even one of the blue LEDs on the board is shifting color like its beeing overdriven.

I've came to the conclusion that this amplifier was a complete waste of money.

You could try a t106-2 core with 20 turns on it.
I had trouble with power inductors cooking at 120 degrees before trying the right t106-2 core.

The tick noise sounds like the chip resetting for some reason.
The inductor over heating might cause this as the inductor inductance will change with excess heat. In an SMPS they used gapped cores to get around this.
 
pinkmouse, the manual states 3.5-4 ohms, and i ran it into 8 ohms.

Also i did not run it at more than a few watts output, nowhere near enuf to cause enough current through the inductors to heat them up to the point of burning.

Sending it back to china is not an option, would cost me more in shipping alone than i paid for the thing.

Yes shipping from sweden is obnoxously expensive, just one of those little LM3886 kits costed me over 50 us dollars to send to the US.
 
The output filter inductors have been replaced and now the heating of the inductors seem to have lessened, i think the amp is even sounding alittle bit better.

The inductors i used are two free samples i got off of CoilCraft.com some time ago.

I'll report back once the amp have been running for a bit.
 
Ok heatsink still gets hot so perhaps that is the gate drive vregs after all, however on the output one channel inductor is luke warm while the other is hot, an indication there might be a big difference in switching frequency between the two channels.

Theres no mention about the trimmer pots but i assume they are for adjusting the gain, if they are indeed for trimming the switching frequency, i may see if i can trim the switching frequency to be somewhat similar on both channels.
 
Ex-Moderator
Joined 2002
I think your best bet at the moment is to download the IR app note, the circuit is exactly the same, only using some SMT components, even down to the numbering. I think the frequency is set using fixed resistors, but can't check easily as mine are all cased up. Keep us updated.
 
The pots are indeed for adjusting the switching frequency looking at the iraudamp7s pdf.

I'll have a look and see if there is a major difference in switching freq between the channels as that is the only thing that can cause one inductor to run hot while the other is just warm.
 
Turns out one channel was almost 100kHz higher in switching frequency than the other.

I've adjusted the higher channel down to as close as i can get to the other, with the scope set to 2µS/div, i set both channels so one half period spans ~1,5 divisions.

Someday im gonna replace these crappy trimmers withj proper multiturn pots as these have literally no friction to them.
 
How about try something for a little more money but likely much higher quality like this

Connexelectronic

Hey! Thank you for posting that link. I never saw this company before. I have been reading about class D / T amps for quite some time. I got a knock-off of the Sonic Impact T-Amp and I also built AMP3 and AMP6 from 41Hz.com. I'd have to say I like all of them very much.

Recently I got one of those 8W / ch. amps from Sure. It was just a bit over $10 shipped. I got it because I wanted to get an example of Sure's stuff. It's OK, I guess. It hisses like crasy. That might be because I'm using a cheapo line lump switching 12V supply.

Anyway... amps on the connexelectronic look really nice. Does anyone have any real experience with them?

James. :)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.