hi guys. i'm a relative newbie too....
i'm just about starting to make the BPA - 200 amp...after a post here, and reading a few, it seems the servos in the An -1192 app notes aren't necessary.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=33268
having said that, making the pcb is a pain cause, hell how do i mount the ic's on the heatsink!!! the 3886 doesn't come in a very heatsink friendly pattern. any help would be really appreciated!!
like, maybe, pcb layout for e.g.
abidr, i would be very grateful if yo would mail/post the schematics of your project. that would gimme a fiar idea about how to get started.
also, lastly, how and where do i get 0.1ohms/5 w resistors. if i don't want to include the srvos, i'll need to have these at the output.
thanks.
i'm just about starting to make the BPA - 200 amp...after a post here, and reading a few, it seems the servos in the An -1192 app notes aren't necessary.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=33268
having said that, making the pcb is a pain cause, hell how do i mount the ic's on the heatsink!!! the 3886 doesn't come in a very heatsink friendly pattern. any help would be really appreciated!!
like, maybe, pcb layout for e.g.
abidr, i would be very grateful if yo would mail/post the schematics of your project. that would gimme a fiar idea about how to get started.
also, lastly, how and where do i get 0.1ohms/5 w resistors. if i don't want to include the srvos, i'll need to have these at the output.
thanks.
No fixation here. I wanted to use the "Elna - for Audio" cap.
I found some 63V 10,000u caps ( strange make ) for Rs110/- .
So the 71 volt type you mentioned is suitable voltage and price wise. I would be buying probably 12 at a time .
I called Cee Pee and they said they would have to order it.
Cheers.
Ashok.
Ashok, before you sink money into those caps, perhaps you should buy just one and post a pic here. Or else I can ask my friend to do the same, only she'll probably be a bit scared to remove the cover from the amp... I'm not sure if these are original or not, because Elna's website does not have pics resembling them. They might be New Old Stock, but in case someone who's used them can comment, that would be good.
0.1 ohm 5W wirewound resistors enclosed in ceramic (often mistakenly called "fusible" resistors by component shopkeepers) should be commonly available in most places.
From the other threads, esp the one on Das Modul, it seems like horizontal placement of the devices would help, if they go through an Aluminium "L" section before being attached to the heatsink.
0.1 ohm 5W wirewound resistors enclosed in ceramic (often mistakenly called "fusible" resistors by component shopkeepers) should be commonly available in most places.
From the other threads, esp the one on Das Modul, it seems like horizontal placement of the devices would help, if they go through an Aluminium "L" section before being attached to the heatsink.
Dear groyne,
In fact pioneer is also supplying custom made resistors. same thing applies to TRIO. They personally know me hence they might hv favoured me. I also buy from Electro syndicate next to Phadgate policechowky Ph: 24471284 and also at shree electronics near Appa balwant chowk. If u still get problem then let me know. I will get then for u.
In fact pioneer is also supplying custom made resistors. same thing applies to TRIO. They personally know me hence they might hv favoured me. I also buy from Electro syndicate next to Phadgate policechowky Ph: 24471284 and also at shree electronics near Appa balwant chowk. If u still get problem then let me know. I will get then for u.
hey palesha,
thanks a lot man! but as of right now, i've put the bpa - 200 on hold. going to make the LM4780 60W stereo amp first. need 2.7 ohm o/p resistors for that. they should be easier to get.
sorry to keep bugging you, but just out of curiosity, do you know if these guys also make toroids? everyone says they'll wind e-i core transformers acc to my specifications but no one will make toroids...not that i'll use one anyway, because they are too expensive.
and, lastly, where is electro syndicate??i've never heard of phadgate police chowky
(in pune for 14 years now.shame on me.)
thanks,
g
thanks a lot man! but as of right now, i've put the bpa - 200 on hold. going to make the LM4780 60W stereo amp first. need 2.7 ohm o/p resistors for that. they should be easier to get.
sorry to keep bugging you, but just out of curiosity, do you know if these guys also make toroids? everyone says they'll wind e-i core transformers acc to my specifications but no one will make toroids...not that i'll use one anyway, because they are too expensive.
and, lastly, where is electro syndicate??i've never heard of phadgate police chowky
(in pune for 14 years now.shame on me.)thanks,
g
10,000 uf 71 v caps
Hi Ashok,
These caps are Available at Cee Pee Electronics , But when I measured them I found their max Capacitance was 5900 uf and can handle only 63 v . and theres fake available too so be care full about choosing these caps.
In case you need them from Cee PEE Refer to Mr Chandresh Hes a nice man and can get you these caps very fast. I know Cee Pee very well.
thanks bye , let me know if more details needed.
Hi Ashok,
These caps are Available at Cee Pee Electronics , But when I measured them I found their max Capacitance was 5900 uf and can handle only 63 v . and theres fake available too so be care full about choosing these caps.
In case you need them from Cee PEE Refer to Mr Chandresh Hes a nice man and can get you these caps very fast. I know Cee Pee very well.
thanks bye , let me know if more details needed.
Thanks.
Hi Arasuk,
Thanks for the info. I actually bought some though Roadkill warned me to buy one and check it. I was in a hurry.
Anyway I found that Elna do not have a 71V 10,000uF cap in their product range. Look at my post on the Chip amps forum ( Fake ELNA capacitors )
http://www.diyaudio.com/forums/showthread.php?postid=389760#post389760
There is a picture there. I exchanged them this evening for Samsung capacitors ( different value).
I bought a TDA7294 last evening for Rs125/-. I wonder if that will turn out to be a dud ! They asked for 140/- but then decided to drop the price. This seems to be about the price others are paying for it (US$2.80).
Hi Arasuk,
Thanks for the info. I actually bought some though Roadkill warned me to buy one and check it. I was in a hurry.
Anyway I found that Elna do not have a 71V 10,000uF cap in their product range. Look at my post on the Chip amps forum ( Fake ELNA capacitors )
http://www.diyaudio.com/forums/showthread.php?postid=389760#post389760
There is a picture there. I exchanged them this evening for Samsung capacitors ( different value).
I bought a TDA7294 last evening for Rs125/-. I wonder if that will turn out to be a dud ! They asked for 140/- but then decided to drop the price. This seems to be about the price others are paying for it (US$2.80).
Really sorry about the capacitors being fakes... anyhow, I guess since you got them exchanged, it's not too bad. I'm building a sub amp right now, I'm using Alcon electrolytics (10000uF, 63V). Let's see how it goes. I'm building it into a plastic case (Gainta), which looks neat and is easy to work with, but horribly expensive (would you believe, Rs. 730 for a 240x160x80 box!).
hi ashok,
I dont know if the tda 7294 could work well as i purchased it for almost the same price 3 of them and blew them all one by one.
might be Fakes, looked good to me but ,sorry !! I had this bad experince , be care full when you are testing those. If It works well let me know and where did you purchase them, I might try It again , as those Tda 7294 Specs boast very well.
Thanks.
I dont know if the tda 7294 could work well as i purchased it for almost the same price 3 of them and blew them all one by one.
might be Fakes, looked good to me but ,sorry !! I had this bad experince , be care full when you are testing those. If It works well let me know and where did you purchase them, I might try It again , as those Tda 7294 Specs boast very well.
Thanks.
Hi Arasuk,
Can you describe how the chips failed. I find others from Europe who have also talked about blowing up chips. They have no reason to get fakes of the TDA series ( I think ).
Anyway chip power amps have quirks and making any small mistake seems to result in a cooked chip.
Hope I can avoid that . If the chip is a fake it will eventually blow.
I also picked up a TDA2050 which I expect to blow !!
Frankly it's disgusting to get caught up with all this fake stuff. I'd rather pay more and get genuine stuff. The cost of the chip is only a fraction of the time and money spent on the exercise.
Look at the "Fake Elna Capacitors" thread and I get even more concerned if we are getting genuine capacitors in our market. Most fake stuff apparently originates in Delhi and Mumbai. Fake Chinese companies must LOVE the Delhi component ( bulk) buyer because he WANTS the fake stuff !
I'm told that if you ask the Chinese supplier to give you a part that costs US$100/- for US$10/- ( like many Indian bulk buyers do ) , they will agree without batting an eyelid. They WILL supply you crap . On the other hand if you make sensible dealings with them you get VERY good stuff !
Can you describe how the chips failed. I find others from Europe who have also talked about blowing up chips. They have no reason to get fakes of the TDA series ( I think ).
Anyway chip power amps have quirks and making any small mistake seems to result in a cooked chip.
Hope I can avoid that . If the chip is a fake it will eventually blow.
I also picked up a TDA2050 which I expect to blow !!
Frankly it's disgusting to get caught up with all this fake stuff. I'd rather pay more and get genuine stuff. The cost of the chip is only a fraction of the time and money spent on the exercise.
Look at the "Fake Elna Capacitors" thread and I get even more concerned if we are getting genuine capacitors in our market. Most fake stuff apparently originates in Delhi and Mumbai. Fake Chinese companies must LOVE the Delhi component ( bulk) buyer because he WANTS the fake stuff !
I'm told that if you ask the Chinese supplier to give you a part that costs US$100/- for US$10/- ( like many Indian bulk buyers do ) , they will agree without batting an eyelid. They WILL supply you crap . On the other hand if you make sensible dealings with them you get VERY good stuff !
groyne asked
"do you know if these guys also make toroids?"
There is a nice manufacturer in Pune.
Torotrans
Ph: 26933077
Call them & u will get the torrodoil as u want.
arasuk said
I dont know if the tda 7294 could work well as i purchased it for almost the same price 3 of them and blew them all one by one.
We hv also bad experience about TDA 7294. Better to use LM3886. It is more reliable.
Hope this info is useful to my friends here
"do you know if these guys also make toroids?"
There is a nice manufacturer in Pune.
Torotrans
Ph: 26933077
Call them & u will get the torrodoil as u want.
arasuk said
I dont know if the tda 7294 could work well as i purchased it for almost the same price 3 of them and blew them all one by one.
We hv also bad experience about TDA 7294. Better to use LM3886. It is more reliable.
Hope this info is useful to my friends here
Having looked at recent posts on the thread I ll provide some of my experiences here in Pakistan.
I ve been using ST micro electronics chips for some time and found that they blow up very easily, solution supply voltage should be around 15% less than recomended volatge, ensure that there is no short circuit as TDA729x data sheets suggests that short circuit protection works well at ZERO INPUT VOLTAGE.
Fake parts and Microchips are very very common here too, and best solution I have found is ask some friend/family member living abroad to send in part or better yet buy them oneslf on foreign trips. All fake items "COURTESY CHINA" and our vendors who want to earn more and more.
LM3886 seems a better choice in Amplifiers and if u could find OPA that 'd be the best chioce.
I ve been using ST micro electronics chips for some time and found that they blow up very easily, solution supply voltage should be around 15% less than recomended volatge, ensure that there is no short circuit as TDA729x data sheets suggests that short circuit protection works well at ZERO INPUT VOLTAGE.
Fake parts and Microchips are very very common here too, and best solution I have found is ask some friend/family member living abroad to send in part or better yet buy them oneslf on foreign trips. All fake items "COURTESY CHINA" and our vendors who want to earn more and more.
LM3886 seems a better choice in Amplifiers and if u could find OPA that 'd be the best chioce.
I fully feel the same way. But when I tell people about RS India, which legally imports genuine parts from the UK and supplies practically all the things which we have discussed on this forum, I almost always get to hear reactions with words like "scam" and "fleecing." And I hear examples of prices of pliers or whatever....ashok said:
The truth is that we have seen thirty or forty posts discussing availability of chip amps in this thread. The NS series of chips are available from RS India for the princely sums of Rs.550 to Rs.650. I don't know whether any of the DIYers on this forum will buy these amp chps from RS India. We seem to have all the time in the world to look for unreliable, lesser known suppliers, because they are cheap. (I include myself very much in this category.) We'll all keep cribbing, keep looking for shady little shops which sell these chips without bills, which will have stocks today but will not know about them tomorrow....
It sometimes does appear that we get what we ask for.
It always looks green at other side. But in reality we hv always read here that fake components r available everywhere. There r many kind of shopkeepers. They r mostly nontechnical people. Further they hv their own resources of buying components. My friend who is a component supplier, also get cheated many times. Hence it is better to select our supplier. On lamington road i hv purchased many IC's till today. I got 10% of my purchase as fake. ok. Next time i don't go to such shops. But just paying 550/- for LM 3886 is horrible. I got it for Rs. 130/- only. They r excellent.
Even i hv purchased TDA7294 from reputed shop in Singapore & 50% of the material was defective. In Singapore the laws r very strict. Still such things r happening.
In mumbai there r genion importers but they supply in bulk. If someone makes group & give the order to such importers, then everybody here can get good material at assured & good price.
Even i hv purchased TDA7294 from reputed shop in Singapore & 50% of the material was defective. In Singapore the laws r very strict. Still such things r happening.
In mumbai there r genion importers but they supply in bulk. If someone makes group & give the order to such importers, then everybody here can get good material at assured & good price.
Hello Mahendra,
I'm in Pune too - have been following this and a few other threads rather silently - I am barely getting my feet wet, and would rather listen to folks like you first! I did a lot of electronic kit building a few years back, so am familiar with Kings, Pioneer, Tejwin, Rajeev etc in Pune. Which place did you buy the 3886 from?
Also, any idea about Indian brands of Drivers? I saw a few threads (Navin, George, Ashok, SSai you and others) where this issue was discussed, but they seem to gravitate more towards drivers from abroad.
TIA,
Neel
I'm in Pune too - have been following this and a few other threads rather silently - I am barely getting my feet wet, and would rather listen to folks like you first! I did a lot of electronic kit building a few years back, so am familiar with Kings, Pioneer, Tejwin, Rajeev etc in Pune. Which place did you buy the 3886 from?
Also, any idea about Indian brands of Drivers?
I saw a few threads (Navin, George, Ashok, SSai you and others) where this issue was discussed, but they seem to gravitate more towards drivers from abroad.TIA,
Neel
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