#qi-hardware IRC log for Thursday, 2016-05-05

arossdotmewhat do you think of this pcb design: http://www.aliexpress.com/item/Finished-HIFI-SA1-TAS5630-stereo-amplifier-class-D-amp-300W-2-AD872-preamp-sn/32433899004.html?ws_ab_test=searchweb201556_0,searchweb201602_2_10017_10034_10021_507_10022_10032_10020_10009_10008_10018_10019,searchweb201603_6&btsid=cff1ee80-0558-4d54-a7dc-273adea26e0b15:31
arossdotmephotos of just the pcb: http://www.aliexpress.com/item/Dual-Channel-2x-300W-TAS5630-Class-D-Digital-Audio-Amplifier-Board-HIFI-AD827-100-New-Free/32327412523.html15:31
arossdotmecompared to: http://www.aliexpress.com/item/High-Power-Amplifier-TAS5630-OPA1632DR-300W-300W-Stereo-Class-D-Audio-Power-Amp-Amplifier/2018214665.html?ws_ab_test=searchweb201556_0,searchweb201602_2_10017_10034_10021_507_10022_10032_10020_10009_10008_10018_10019,searchweb201603_6&btsid=993f7336-1762-44b3-bd4f-5130b75bf71015:32
arossdotmeno box pcb design: http://www.aliexpress.com/item/TAS5630-power-digital-amplifier-board-300W-2-free-shipping/1581574057.html?ws_ab_test=searchweb201556_0,searchweb201602_2_10017_10034_10021_507_10022_10032_10020_10009_10008_10018_10019,searchweb201603_6&btsid=320148f8-3b96-47bf-a7fd-76511c5d402d15:32
arossdotmeboth use the same TI audio power amplifier IC. they use different pre-amp ICs15:33
DocScrutinizer05arossdotme: wire to speaker terminals in first one look flimsy18:17
DocScrutinizer05second one looks way better design - the input are farther away from the speaker terminals and it seems they got the preamp directly behind the inpout jacks, not on other end of main PCB like first one18:23
DocScrutinizer05I'd go for second one for sure, even when it's 30 bucks more18:24
DocScrutinizer05however keep in mind you need a stable powerful 40V supply18:24
DocScrutinizer05(or 25V, or higher)18:25
arossdotmemy dilemma was i like the case, connectors look more robust and easier too. and the vol pot was not on the same pcb. arr well i guess if i really want i can make my own case with the board only version of the 2rd one :)18:26
arossdotmeyea the power supply issue.....18:27
arossdotmei have a 400w stepup dc-dc converter. i found it can give double the input voltage.18:28
arossdotmei also have a 100w boost converter too. that seams able to do 3x the input :). hmm. 18:28
arossdotmeits min in voltage is 3.somethingV wheres my 400w one is 8v18:29
arossdotmei heard that one can get multiable PSUs and wire the DC in seriels to get a bigger voltage :), dad said to make sure the dc ground is not connected mains earth.18:30
arossdotmeor i would just by a mains one if i rally want.18:31
arossdotmemy use for it it so power one 150w peak PA speaker i was given.18:31
arossdotmeI assume the amp will be ok if one speaker is no connected ?18:31
arossdotme*(so i want around 75w constant). its a 8ohm speaker too.18:32
arossdotmei thought this amp would be easier. instead of  http://www.yuan-jing.com/irs2092-class-d-mono-amplifier-board-200w  a with  http://www.yuan-jing.com/Voltage-Converter/12v-to-32v-dc-to-dc-converter-board-a to power it. as i looks like i would need to mount the mosfes on big heatsink urrgg. it would work well of a 12v batt though... mmh18:37
arossdotmealso sure make a board mono board for this the 2x150ishW version of the TI IC http://store3.sure-electronics.com/1-x-300-watt-class-d-audio-amplifier-board-tas561318:39
arossdotmewhich has the advantage of only needing 36V in i think it was. only a few £ bewteen the 300w mono TI and 300w 2x TI. hmm arrgh what to do?...18:40
arossdotmewhat do you think of the sure mono board?18:40
arossdotmeno pre-amp on the sure one18:41
DocScrutinizer05you want DC input power?18:47
DocScrutinizer05the sure thing... well it has a fan. Though that makes sense, I don't really like fans18:55
DocScrutinizer05can't say much about it, except it's not even listing specs for 8Ohm load, which doesn't mean 8Ohm won't work, just that the supposed 300W for sure won't be available18:56
DocScrutinizer05it also doesn't list THD at a more reasonable operation point, like 200W. Despite this would be a way more relevant data.  10% THD are unbearable (except for max load, which you're not supposed to use on a regualr basis during everyday operation anyway)18:58
DocScrutinizer05http://www.aliexpress.com/item/High-Power-Amplifier-TAS5630-OPA1632DR-300W-300W-Stereo-Class-D-Audio-Power-Amp-Amplifier/2018214665.html?ws_ab_test=searchweb201556_0,searchweb201602_2_10017_10034_10021_507_10022_10032_10020_10009_10008_10018_10019,searchweb201603_6&btsid=993f7336-1762-44b3-bd4f-5130b75bf710  is sort of shitty design too, the heatsink inside case can not get rid of the heat since no ventilation slots in the case 19:01
DocScrutinizer05above the heatsink19:01
DocScrutinizer05for operating the device small side down, the heatsink's wings are wrong orientation19:02
DocScrutinizer05and I *hate* all aliexpress pages since you can't c&p the text they have19:03
DocScrutinizer05anyway efficiency 88% which means 300W*0.12 = 36W the heatsink must dissipate19:04
DocScrutinizer05you probably should operate that thing without the upper lid, just like shown on the webpage ;-)19:05
DocScrutinizer05oooh wait, that's a 300+300W, so make that 72W, nooooo way19:06
DocScrutinizer05with that heatsink no way19:06
DocScrutinizer05of course you can ignore all this as long as you don't actually use the thing to drive your speakers at constant high power19:08
DocScrutinizer05and you'd be surprised how little difference in volume you notice between N Watts and N/10 Watts19:09
DocScrutinizer05I'd guess that device can actually do a 100W continuous 19:10
arossdotmeyea im not keen about the fan also meh19:11
arossdotmedc input pwr yes19:11
arossdotmebatts, etc19:11
DocScrutinizer05then get enough voltage from the batts, way better than boost converter19:11
arossdotmei expect half of 300w. according to the TI datasheet19:11
DocScrutinizer05ooh china Watts19:12
DocScrutinizer05I see19:12
arossdotme300w into 4ohm19:12
DocScrutinizer05whatever, cya - dinner19:12
arossdotmek got dog wall too19:12
arossdotmethanks muchly19:12
arossdotmewith the TI chips the THD goes bad to the 10% when its clipping anyway :)19:13
arossdotmeI dont expet to use full watts out19:13
DocScrutinizer05a last funny note: I *love* tiny reed contacts, make nice stealth switches in cables19:13
arossdotmebtw this is the manufacture of them http://www.yuan-jing.com/ClassD-T/tas5630-class-d-stereo-amplifier-board-300w-300w-delux19:15
arossdotmethanks for the heatshink, info. very educational :)19:16
arossdotmegot this from them, but its noise floor is really suckly. bitty/gritty blips. http://www.yuan-jing.com/lm1036-audio-tuning-board-delux-version19:19
arossdotmethey make this board designed by audiopiles from diyaudio.com http://www.yuan-jing.com/tpa3116-class-d-2-0-stereo-amplifier-board-50w-50w19:20
arossdotmeTAS5630 2x300w without heatshink version : https://www.yuan-jing.com/tas5630-class-d-stereo-amplifier-board-300w-300w?search=TAS5630 19:22
arossdotmetiny reed contacts for stealth switches in cables? trying to picture that... :/19:22
arossdotmebut for the fan (urrg) heatsink what did you think of the sure board other wise? i think it was ok19:25
arossdotmethey do a stereo version but with no pre-amp :(19:25
DocScrutinizer05though... see above19:25
arossdotmeoh ok. i thought i was for both... ok i see19:26
arossdotmesee ya, been great19:28
DocScrutinizer51arossdotme: (reed) a glass tube with axial contaxts. possibly as small as qwmm long and 2.7mm diameter20:53
DocScrutinizer51there are way smaller ones too20:53
DocScrutinizer5112mm long20:55
limpkinhey gents....  out of curioisity, is werner's here? and what's his nick? :)21:39
arossdotmeDocScrutinizer51, and stealth switches in cables? what application would you use them for?21:44
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