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

[ddashk]

hi
i ordered a 2*100w from sure. the one with the fan on top but the one that just arrived looked just the same as the 4*100w. whats the difference?

[ddashk]

i know i have the 2*100w version but the layout is the same.i managed to get my offset from 374 and 118 to 11.2 and 2.3. first i got them as low as possible with the resistors as standard. for the first channel i got it down to 310and then left the trim pot in that position while i drew graphite pencil across the resistors. trimming the pot first makes it easier to find the spot right in the middle befor you make the pots twitchy

[loleskater]

Do you need to use some other heatsink with the amp when you are lowering the offset voltage?
Or dont the chips heat up if they are just sitting at idle with no input?

[ddashk]

it took me about five minutes to set the trimmers and the chips were still only warm at that point

[mattnz]

Originally Posted by ddashk

it took me about five minutes to set the trimmers and the chips were still only warm at that point

Im new to the DIY audio scene, I have tried searching but still dont understand what the offset voltage is for and why you adjust it?

Also I how well do these amps run large speakers Im looking at using a 4 x 100 board to bi amp a pair of mission speakers they are rated @ 150w / 92db sensitivity. each speaker has 3 x 8 inch woofers and a tweeter.

Thanks

[teamacc]

DC offset is the difference in the + and the - on your speaker. This is the voltage that always loads your speakers, so your speakers will be loaded, which causes less lifetime and maybe worse sound.
Best to set DC offset to zero, as speakers work on AC.

[mattnz]

Originally Posted by teamacc

DC offset is the difference in the + and the - on your speaker. This is the voltage that always loads your speakers, so your speakers will be loaded, which causes less lifetime and maybe worse sound.
Best to set DC offset to zero, as speakers work on AC.

Thanks

[the7trumpets]

I'm thinking of building a pretty big unit out of these for whole house distributed audio, and wanted to get some feedback from those of you who know the intricacies of these amps.

I'm creating seven zones (kitchen, 3 bedrooms, 2 baths, backyard) with used airport expresses on ebay. The output of those will go to these amplifiers, and then to some ceiling speakers I'm installing. The whole system will be controlled by the computer / iphone / ipod touch. I was originally planning on building seven amps and mounting them in each room along with each airport express, but then I realized that would be needless and ugly. Then when I saw the 4*100 amp, I figured I could cut down on cost and make it look better by mounting all the amps - 4 4*100 boards for 16 channels (14 used) - in a single rack mount chassis with my network gear.

I could just get two 7.1 receivers off of ebay, but it would cost just as much, probably wouldn't sound as good, and hey, I need a fun electronics project that has the potential to annoy the wife and amaze the friends


Then I came and read this thread, and it seems some mods are much harder to do on this version of the board. And to top it all off, I just went to sure electronics site, and they say they are out of stock of the 4*100 boards. So, I have a few questions:

1. Are these 4*100 boards production ready yet, or are they still having major issues with them?

I probably will lift the input limiters, and I'll need to adjust the input gain (probably with constant resistors rather than a pot) so as to never clip from the output of the airport expresses. Will I have to adjust the DC offset?

2. The 'manual' if you want to call it that mentions a 'sleep / mute' function. Is this something that is already implemented when the audio signal goes to zero for a while, or do I need to design a circuit for this functionality if I want to use it?

3. What current of power supply would i need to drive 4 of these boards in a single chassis, or how many of the Meanwell 350W supplies would I need?

It might be cheaper just to get 2-4 of the 350W Meanwell supplies, the higher current supplies I'm finding are pretty expensive:
SE-1500-27, Mean Well SE-1500-27
RSP-1000-27, Mean Well RSP-1000-27
SP-750-27, Mean Well SP-750-27
SE-6000-27, Mean Well SE-600-27

I don't anticipate running this thing full bore, I just want headroom so that music with lots of dynamic range sounds good. If I turned all the speakers on in the house full blast, I would probably run outside because it would be too loud.

4. Does the fact that they are out of stock mean they are changing them somehow? What should I know about what they are changing, if anyone knows?


Thanks!

[poler]

I ordered a board as well. I'm interested in knowing if anybody has any info on when will they ship.

[the7trumpets]

One more question to add:

Most of these power supplies I see have an input voltage range of 90-132V.

It's a long story, but our power company insists on giving us 'extra' voltage. I have measured the line voltage as high as 149V here, or as low as 134V. What precautions if any would I need to take, given that ugly situation?