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View Poll Results: Was a good idea to use two lm1875 or a big stk chip
Use stk 8 27.59%
use lm1875 21 72.41%
Voters: 29. You may not vote on this poll

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Old 17th March 2013, 07:14 PM   #241
PetruV is offline PetruV  Romania
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Arent those lm1875t fakes,also is that 2n3055 fake?,al my chip amps were bought from the same shop and no one worked!coincidence?i might have been scammed,only my tda1517 was from a separate shop,that died from my mistake.
I really dont think those are real chips,they didnt work,i tried the other tda2822m with zobels and it didnt work,also the lm when they worked they sounded like crap
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Old 20th March 2013, 06:51 AM   #242
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I told you from the beginning of the thread to use linear supplies, not SMPS.
You don't tell anything about the load: what kind of speakers are you attaching at amp's
outputs ?
I believe that the STK xxx-120 that I own is targeted as a 120 W amplifier, also seeing the transformer and the voltage of the PS caps.
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Old 20th March 2013, 08:59 PM   #243
PetruV is offline PetruV  Romania
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Quote:
Originally Posted by picowallspeaker View Post
I told you from the beginning of the thread to use linear supplies, not SMPS.
You don't tell anything about the load: what kind of speakers are you attaching at amp's
outputs ?
I believe that the STK xxx-120 that I own is targeted as a 120 W amplifier, also seeing the transformer and the voltage of the PS caps.
i tried the lm1875t on a linear supply,the distorsion is excessive,so i took them apart,so now please tell me if you know,are they original
i tried all my speakers,it sounded like crap,but i really think thats how all lm1875 sound,i would have used a tda 2003 since its better in every way but i needed something to work at 25+-,so please recomend me something else
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Last edited by PetruV; 20th March 2013 at 09:02 PM.
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Old 21st March 2013, 03:44 AM   #244
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Quote:
Originally Posted by PetruV View Post
i tried the lm1875t on a linear supply,the distorsion is excessive
On which load ?
I would recommend the popular and more powerful LM3886.
Or, since you have showed the popular 3055 transistor, the JLH amplifier.
It reguires a single voltage regulated power supply, around and no more than 30V, and it works in class A
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Old 21st March 2013, 07:54 AM   #245
PetruV is offline PetruV  Romania
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Quote:
Originally Posted by picowallspeaker View Post
On which load ?
I would recommend the popular and more powerful LM3886.
Or, since you have showed the popular 3055 transistor, the JLH amplifier.
It reguires a single voltage regulated power supply, around and no more than 30V, and it works in class A
I was thinking about class a since im building a lot of high powered amps,a little one would be needed,but i have split supply 18 0 18 from toroid which after rectification is 25 0 25.
The lm3886 is expensive nd probably too powerful for the toroid so im going with class A

So please link me to a simple class a shematic,which also includes pcbs since my projects built on perfboard never work,maybe because of high contact resistance.
Thanks in advance

I am also building an apex d200 powered at +/- 75v,but i need a smps project for it,i aleardy have one of the pcbs etched and with some components
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Old 24th March 2013, 08:54 PM   #246
PetruV is offline PetruV  Romania
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Anyone know of a good discrete design that works at 25v split supply
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Old 30th March 2013, 09:53 AM   #247
PetruV is offline PetruV  Romania
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from now on all talk about my stuf will be posted in this thread,so please go there and there i will ask all my questions and you can say anything you want
link
http://www.diyaudio.com/forums/everything-else/230758-petruvs-corner-forum.html
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Old 1st April 2013, 06:33 AM   #248
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excuse me sir, I want to ask. for my LM1785 schematic below, what were the results. please recommended and what needs to be removed or replaced with good.
for a long time did not play LM, tried to open the PC computer, I found the scheme. Thank you,
regards KDTS
Click the image to open in full size. lm1875 tosibai.png
Click the image to open in full size. DIY-Audio-Power-Amplifier-LM1875-bridge-2SA1943-2SC5200-100-Watt.jpg
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Old 4th April 2013, 06:22 PM   #249
PetruV is offline PetruV  Romania
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what youre showing us is a buffered lm1875 which is pointless since youre limited by the max voltage that can go in the chip,meaning you can oly get higher power if you use lower impedance
Just dont build that schematic,if you want higher power use tda7294
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