Sure Electronics New Tripath Board 4*100W class-D Amplifier Board

[pheonix358]

Sorry, forgot to mention, mine was the improved, problem fixed board.

Terry

[aquapiranha]

Still waiting for my replacement (Sure have tracked it and it left HK on the 15 September, so to take this long implies it has been lost) I will post my findings if / when it arrives. I hope it works!

[obsoletemac]

<intro>
Hello.
I've been lurking here for a few weeks, and was inspired by this thread (and the one about the 2-channel version) to reboot my HiFi-interest. (Well, maybe moving to a larger house with room for decent speakers have something to do with it as well)
</intro>

I just received a 4-channel Sure-board, and reading about the magic smoke being let out at first try, and about missing isolation-washers, I wanted to test mine out immediately.
First the washer; it seems to have been poorly mounted and gets pulled towards the mounting screw when it's being tightened. With a little care, there will be no short, however.
After setting things up with an Oltronix lab-ps (20V 1.5A) a pair of speakers (computer-monitor pulls) and an iPhone for source, I swithched the power on, but was greeted by a whining noise from the speakers. This was due to the current limiting set to 150mA, and went away with more "juice"
With everything working, and no smoke billowing out I was greated by far better sound than I had expected!
I look forward to box this amp and hook up some serious speakers!
Thanks everyone for the inspiration!

[pheonix358]

The problem must be weird. Sure can make very good boards as apart from a few who have fried them while modding the 2*100 board doesn't seem to have any problems.

When mine fried it was spectacular. There was lots of smoke!!!! It also shut down the 13A power supply. Since the amp was just sitting there, powered but otherwise not doing anything and the epesode was faster than I could react......... . It would seem like a short on the power rails. I would be thinking in terms of a physical problem as opposed to an electronic one. The amp was fine for several days, was kept cool by a fan and was idling only. The sound it made was just like one that a dirty pot would make, sort of scratchy.

Terry

[pheonix358]

Interestlingly the resistance on the outputs now show
ch1 22 Ohm
ch2 32k Ohm
ch3 32k Ohm
ch4 0.5 Ohm

Looking at the diagrams put up by Cybermeu, I don't see a connection between Ch1 and 4. If anyone else cares to check their defunct boards. May be an issue with mounting the two boards.

Terry

[pheonix358]

Another thing I noticed on close inspection, if you sight along the edges of the board, they have a slight bow. Once again this tends to indicate a physical rather than electronic problem.

Terry

[hubsand]

I just got a replacement 4x channel board from Sure: previously some of them have been a bit bowed, but the new ones a) aren't, and b) don't expire on power-up!

[pheonix358]

Originally Posted by hubsand

I just got a replacement 4x channel board from Sure: previously some of them have been a bit bowed, but the new ones a) aren't, and b) don't expire on power-up!

The one I have is bowed by a couple of mil only with the heatsink attached. Mine also lasted two days before it went poof. I suppose this could be considered an improvement.

[hubsand]

Hope I didn't post too soon! Mine is only one day old . . .

[critofur]

I got my 4*100 a few days ago. Mine's been powered up for more than 24 hours, played some music yesterday and more today, no problems. No noise whatsoever. When the music is stopped the speakers and the amp are both completely silent. (can't hear anything in my fairly quiet room, at least).

I'm powering my amp w/ a dinky 12V 2A external HD "wall wart" at the moment. Don't have any 24V supplies to test.

So far the amp sounds pretty good, playing back EAC ripped music on my PC as the source. A pair of sealed Zaph BAMTMs as the speakers.

EDIT: Oh, my board is also bowed (bent) - should I contact Sure about that, should I be concerned? I'm not too concerned, because most of my recent computer motherboards all bow when you install the CPU heatsinks. I don't like it but, I read that's "normal"...