+/- 90v smps looking for simple design

I would not get involved with suggesting PetruV dangerous high voltage stuff for his own safety .
This is a free sample of his postings:
um no,i get upset very easily and i WILL cuss at people that say anithing badd about me,i will leave this forum if necessary,im a desoriented person and i work on many things at once,nothing works for me but works for many others,i ont have two whole friends irl,i know what im doing and im am from a scale of 1 10 10 being pro and 1 being noob,im around 6-7.
I will leave this forum if someone like this pisses me off next time like this,you were supposed to be here to help me when i need some help,youre only making it harder on me, Im aleardy tired of living on this world.if you were in front of me right now i would have beaten you by now,the way everibody at scool beats the crap outa me untill i fall or they paint thw walls red with me,i havent died by now.
please dont call me a troll because im disoriented,im not dumb.
I wasted 2 months tryng to ge you to help me so youre the trolls,abusing of the weak and disoriented.:eek::eek::eek::eek::eek::mad::mad::mad:

His outburst was the answer to this reply:
Quote:
Originally Posted by johnr66 View Post
I don't know if he is a troll, so I won't call names. He is very unfocussed and asks too many questions (he says he is a 13 year old kid). Most have given up on him including myself. He needs to go learn instead of asking questions so often. He needs to get his 12v chip amps working right before even thinking about discrete jobs with 190 volt rail to rail voltages!
 
im not going to build a smps,but im going to reuse this thread for posting updates and photos on my progress as my main thread so i dont have to make more threads.3 i think is enough!

This is my d200 which is my first pcb i ever made,looks pretty good,but 3 tracks are interupted but its an easy fix
 

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For another project: Do any of you know of a good simple class a amplifier design that operates at +/- 25v.
I have an old case with trafo,i aleardy tryed the lm1875t but i got fake chips,its hard to not get fake chips.So i have settle on class A since i might not need a lot f power in that amp
 

palstanturhin

Member
2011-06-17 11:26 am
You are asking for trouble again. Do you understand class-A?

My suggestion:
Stay with your LM1875 designs.Lots of info about them in here. Many PCB designs to choose from.
LM1875 is good in all aspects. Sound is amazing. The chip is one of the best there is...
Make that work first.
 
You are asking for trouble again. Do you understand class-A?

My suggestion:
Stay with your LM1875 designs.Lots of info about them in here. Many PCB designs to choose from.
LM1875 is good in all aspects. Sound is amazing. The chip is one of the best there is...
Make that work first.
lm1875t sucks,i aleardy had it and when it decided to work it sounded like crap,everithing else but lm1875t
I think i going to use thos class d amps that dont need a heatsink
 

palstanturhin

Member
2011-06-17 11:26 am
LM1875 outperforms easily most of the ordinary home amplifiers and definitely any available compact stereo...
You must have done something seriously wrong with yours if it was 'crap'.

Some have an opinion that LM1875 sounds even better than LM3886 or -75... And there are equipment available worth thousands of $$$ or €€€ and are considered to be high end quality, with those chips inside...

So if your 1875 was crap, do not even think about more complex circuits before you got decent sound from that first.
 
I think it was a fake chip

Why blame the chip?:confused:

This is the circuit you built: a single supply amplifier where you did NOT use the input biasing to 1/2Vcc, I still wonder why.
The schematic is corrected by your own hand:

[IMGDEAD]http://imageshack.us/a/img832/8139/dscf2872d.jpg[/IMGDEAD]

No wonder sound was "crap".

Now, if you boldly disregard the datasheet instructions, what can be expected in a more complex project?

FWIW this is your implementation of said LM1875 amplifier :

[IMGDEAD]http://imageshack.us/a/img845/6995/dscf2871s.jpg[/IMGDEAD]

Not dissing your job at all, we *all* began noobs, but jumping from this (which didn't even work) to a +/-90V rails amplifier, is a little too much.

And trying to build an SMPS to power it, even more dangerous.
 
i changed the schematic may times,finaly settling to the split supply in the datasheet,the results were poor,kind of a echo in the sound,the sound in the backround sounded like tearing paper to the beat of the drums.
It was sure something wrong with the chips.
To repair that amp im going to go full discrete since the cipamps are very few to choose from.
Can anyone recomend me a chip amplifier that works at 25v x2
I said im not building smps for it

Most of my amps never worked untill today when i made a tda2003 2 chanels and it worked,i thiink that amps dont work on breadboars due to poor layout causing crosstalk
 
A linear supply will be more reliable.

I got into the irs27951 and that was a nightmare to get going even with lots of help.

I grabbed a resistor once after forgetting to switch off the smps and got a tingle.
Had I grabbed a live rail I might not be typing now !

My view is I got into smps, learned a lot now its best to leave it there and stick to linear supplies.