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Old 12th April 2010, 08:15 PM   #1331
v-bro is offline v-bro  Netherlands
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Quote:
Originally Posted by thierry38efd View Post
Hello,

i've try to connect the fan ground the main ground,it is very efficient

but as you said,the best way is passive heatsink.
the new kits are comming with two heathsink,it's very easy to build it.
elsewhere,you can use pentium heatsink (with a saw to cut it,for insert it on the kit...).

yes,the Zobel are in a big size,it's very easy to change values of capacitor or resistor ) ,the best listening is 470nF+10 nF.
i know lower size have same effects.

see you.
I can't see why Sure hasn't connected it to the main ground by default?!

A passive heatsink is fine, but generally a designer evaluates the correct functioning of his design by measuring the temperature and when it is too high you connect a scope to the switching waveform to see what's going on. The temperature you guys are all mentioning makes me suspect there is something going on there, like I've said a few times now... It shouldn't get so terribly hot. I can cool my TK2050 amps with a thin and tiny slab of aluminium when I run them at 24Vdc! Can someone back this up? Kristleifur? You can place the whole world of aluminium on top to keep it cool, but if the cause of the problem is elsewhere why would you? In Dutch there's an expression for this, literally translated:"Mopping with the tap open..."

Then why on earth would you alter the zobel? Perhaps it gives a satisfying skewed frequency response, but the same applies here, when the problem lies elsewhere (usually in the speakers) why would you? You guys HAVE to understand the output filter has only little relationship to the audio quality itself. Sure it has an effect on the flatness of the response, but using audio grade components here is asking for other problems. Like emissions, one day you'll notice your TV starts distorting when the amplifier is turned on, or some wireless device is not working or going mad, or stuff just dies around you.... whatever.... This is HF, not audio. In HF a designer tries to keep things small and well accompanied by ground in a certain way to prevent EMC and EMI issues. Component choice is key to get the filter to even operate. This choice is rather NOT dominated by audiophile considerations. Like we don't want large PP caps there! Even the Sure designers understood well what to choose (and convenient for them the better choice here is often even cheaper!), hence I would even advise to keep this part unchanged. The ONLY improvement in the output filter, both in consumption, temperature and audio quality will be found in better inductors!

But also here I say the choice is yours....

Even though I find some parts a bit exaggerated, yet he even could have added things on top which he stayed silent about in the article (compensates the exaggeration well ) here's a very good read:
http://www.audioholics.com/education...-basics-page-2
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Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

Last edited by v-bro; 12th April 2010 at 08:22 PM.
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Old 12th April 2010, 08:33 PM   #1332
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Default Meanwell Fan

Yes, I think it may have a malfunction.

I use a single Meanwell driving two 4X100's and the fan has yet to come on.

My PS is is an oversized all metal enclosure. I am sure that helps.

And the two 4X100' boards are each in their own metal enclosure.

Time to check primary wiring and grounds!

Last edited by alevans51; 12th April 2010 at 08:36 PM. Reason: Expansion of original response.
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Old 12th April 2010, 08:36 PM   #1333
v-bro is offline v-bro  Netherlands
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Quote:
Originally Posted by DarpMalone View Post
I'm currently running a SureElectronics 4x100 amp with a 27V / 350W Meanwell SMPS and the Meanwell fan goes on every 15min or so for aprox 1min duration (and yes, it's VERY loud)... Someone suggested that I correct the DC offset on the board (which I've managed to get down to almost nil, by shorting the resistors) but it didn't make a difference, the fan still turns on regularly. Perhaps I've just got a faulty PS?
Hence my preaches to avoid anything with a fan and just build a plain and simple good 'ol linear supply!

But this is a bargain hunters thread, thus my preaching will probably be invain...

Really the idle current of this amplifier is probably enough to make the fan switch on. The offset trimmers can have a little effect, but not much. If it changes much then your speakers will have smoked out long before that. The trimmers on the sure board are single turn junk by the way, a good mod actually would be to mount some good Bourns multi turn trimmers there. At least then you can be certain that after playing loud a good rock track your offset will remain unchanged!

I have repaired a Passlabs X150 a short while ago which had single turn trimmers. I had the idle current and DC offsets trimmed nicely after breaking serious sweat and after I just gently tapped on the board I could start all over again. Pulled the suckers out and cuisined some nice 15 turn trimmers in, now it is running solid!

That said I am a bit afraid the Sure board doesn't allow for much larger trimmers, but Bourns have a miniature version as well....

Without proper examination of your Meanwell supply it's very hard to say why the fan is turning on and whether it is normal operation or not...A good start is to start at the load, measure the current consumption. Or an IR thermometer could perhaps provide some answers. Or maybe you can work around it by choosing a different fan. But then be sure the consumption is the same! And the air displacement! And of course the voltage!!
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Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

Last edited by v-bro; 12th April 2010 at 08:42 PM.
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Old 12th April 2010, 08:37 PM   #1334
teamacc is offline teamacc  Netherlands
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Edit: until resolved: Dont try

Found something:
According to the Tripath datasheet, the config pin (pin 24) should be connected to Vcc, whereas sure connects it to the ground.
With pin 24 to ground, the TK2050 acts as a stereo amp chip, whereas it is a bridged amp chip.
Quote:
For stereo mode operation, the TK2050 is a dual full bridge. For parallel mode operation, the TK2050 can be configured as a single full bridge with double current capability by connecting the CONFIG pin to the VDD pin of the TP2050
If this actually is something that might work, all credits go to elfishi, who first posted about him connecting pin 24 to Vcc
Edit: Until resolved: Dont try

Last edited by teamacc; 12th April 2010 at 09:00 PM.
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Old 12th April 2010, 08:58 PM   #1335
v-bro is offline v-bro  Netherlands
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Quote:
Originally Posted by teamacc View Post
Found something:
According to the Tripath datasheet, the config pin (pin 24) should be connected to Vcc, whereas sure connects it to the ground.
With pin 24 to ground, the TK2050 acts as a stereo amp chip, whereas it is a bridged amp chip.


If this actually is something that might work, all credits go to elfishi, who first posted about him connecting pin 24 to Vcc
Edit: and if it doesnt work, blame elfishi :P
The board design is for non paralleled operation!! So NO don't connect Config to VDD I'd say. This would halve all series components in the output filter and place all parallel parts (like the zobel) offside!! It would turn the whole output filter in to a gigantic mess!!

EDIT: At hind sight the Sure board IS for parallelled TP2050 configuration, the Sure documentation present something that in my view wouldn't even work. If both bridges in each chip would work in counter phase (Config pin to GND, 'stereo' operation on the chip) then a board design for parallel operation would short circuit them out completely... Config would HAVE to be tied to VDD...
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Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......

Last edited by v-bro; 12th April 2010 at 09:25 PM.
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Old 12th April 2010, 09:35 PM   #1336
v-bro is offline v-bro  Netherlands
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There is just an error in the sheets I hope... it couldn't be like this on the Sure board!!

Pic1 From the Sure sheet
Pic2 From the Tripath datasheet
Pic3 Description from the Tripath datasheet
Attached Images
File Type: jpg Sureshort!.JPG (40.5 KB, 379 views)
File Type: jpg Sure not short!.JPG (35.2 KB, 372 views)
File Type: jpg Sure not short datasheet.JPG (30.4 KB, 367 views)
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Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
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Old 12th April 2010, 10:42 PM   #1337
v-bro is offline v-bro  Netherlands
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This hits the spot! The disclaimer in the Sure documents...Click the image to open in full size.
Click the image to open in full size.
Attached Images
File Type: jpg Surecrap.JPG (8.8 KB, 436 views)
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Max. cone displacement can be several foot on any speaker!Too bad it can be done only once......
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Old 13th April 2010, 02:24 AM   #1338
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[QUOTE=v-bro;2151349]I can't see why Sure hasn't connected it to the main ground by default?!

it's so easy to use a comercial fan with its own wire.,this is a chinese amp,they won't add a couple of wire outside the board.this is a cheap amp,not the best design.
like the capacitor for analog low pass filter


A passive heatsink is fine, but generally a designer evaluates the correct functioning of his design by measuring the temperature and when it is too high you connect a scope to the switching waveform to see what's going on. The temperature you guys are all mentioning makes me suspect there is something going on there, like I've said a few times now... It shouldn't get so terribly hot. I can cool my TK2050 amps with a thin and tiny slab of aluminium when I run them at 24Vdc! Can someone back this up? Kristleifur? You can place the whole world of aluminium on top to keep it cool, but if the cause of the problem is elsewhere why would you? In Dutch there's an expression for this, literally translated:"Mopping with the tap open..."

ok,before build this amp,i've try a UCD topology (with post filter feedback)
i gave up this design because of bad THD,due to the layout,class D amp need SMD component.


the link
IR2110 failure with a scope probe

Then why on earth would you alter the zobel? Perhaps it gives a satisfying skewed frequency response, but the same applies here, when the problem lies elsewhere (usually in the speakers) why would you? You guys HAVE to understand the output filter has only little relationship to the audio quality itself. Sure it has an effect on the flatness of the response, but using audio grade components here is asking for other problems. Like emissions, one day you'll notice your TV starts distorting when the amplifier is turned on, or some wireless device is not working or going mad, or stuff just dies around you.... whatever.... This is HF, not audio. In HF a designer tries to keep things small and well accompanied by ground in a certain way to prevent EMC and EMI issues. Component choice is key to get the filter to even operate. This choice is rather NOT dominated by audiophile considerations. Like we don't want large PP caps there! Even the Sure designers understood well what to choose (and convenient for them the better choice here is often even cheaper!), hence I would even advise to keep this part unchanged. The ONLY improvement in the output filter, both in consumption, temperature and audio quality will be found in better inductors!

sorry,i wrote something false,zobel is 470nF+10 Ohms.
i own a digital scope meter,the SURE kit do not have a zobel on the output.
you can check it easily.


But also here I say the choice is yours....

Even though I find some parts a bit exaggerated, yet he even could have added things on top which he stayed silent about in the article (compensates the exaggeration well )

as i said,in this case,component size are very easy for me to exchange,the size do not deteminate the quality of the amp.
i won't take the soldering station for 2 SMD components.
next i will post some THD and IMD measurement
.

Last edited by thierry38efd; 13th April 2010 at 02:38 AM.
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Old 13th April 2010, 02:39 AM   #1339
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Quote:
Originally Posted by teamacc View Post
I just got a reply from sure regarding the mixing up between the 4 channel boards with 2 channels enabled, and the real 2 channel boards:

So if you want to mod your amp like in this tread, you best buy the AA-AB013
Any other input on the two different boards? I think the 4*100W looks good. Can I use only 2*100W on that board, will the other 2 channels still draw power if unconnected?
I'd like to avoid the fan version if possible.
Click the image to open in full size.

Click the image to open in full size.
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Old 13th April 2010, 07:47 AM   #1340
mattnz is offline mattnz  New Zealand
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Quote:
Originally Posted by Nick122147 View Post
Any other input on the two different boards? I think the 4*100W looks good. Can I use only 2*100W on that board, will the other 2 channels still draw power if unconnected?
I'd like to avoid the fan version if possible.


I think so it says on Sure's website "You can use any number of channels you like, and leave the others unused"
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