+/- 90v smps looking for simple design - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 22nd March 2013, 08:00 PM   #11
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
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
Attached Images
File Type: jpg DSCF2993[1].jpg (644.0 KB, 517 views)
__________________
I know everything but do nothing
  Reply With Quote
Old 22nd March 2013, 08:31 PM   #12
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
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
__________________
I know everything but do nothing
  Reply With Quote
Old 23rd March 2013, 09:40 AM   #13
diyAudio Member
 
Join Date: Jun 2011
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.
  Reply With Quote
Old 23rd March 2013, 12:57 PM   #14
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
Quote:
Originally Posted by palstanturhin View Post
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
__________________
I know everything but do nothing
  Reply With Quote
Old 23rd March 2013, 02:21 PM   #15
diyAudio Member
 
Join Date: Jun 2011
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.
  Reply With Quote
Old 23rd March 2013, 06:43 PM   #16
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
I think it was a fake chip
__________________
I know everything but do nothing
  Reply With Quote
Old 23rd March 2013, 08:28 PM   #17
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
Quote:
Originally Posted by PetruV View Post
I think it was a fake chip
Why blame the chip?

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:

Click the image to open in full size.

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 :

Click the image to open in full size.

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.
  Reply With Quote
Old 23rd March 2013, 09:35 PM   #18
norazmi is offline norazmi  Malaysia
diyAudio Member
 
Join Date: Feb 2008
exploding.... petruv we know you want powerfull amp to be build by your own hand, but you must learn and look what people suggest to you and with patient, there is no way to jump with higher knowledge unless you learn and learn with patient...
  Reply With Quote
Old 23rd March 2013, 09:39 PM   #19
PetruV is offline PetruV  Romania
diyAudio Member
 
Join Date: Dec 2012
Location: Bucuresti
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
__________________
I know everything but do nothing
  Reply With Quote
Old 23rd March 2013, 09:54 PM   #20
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
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.
__________________
PCBCAD50 software. http://www.murtonpikesystems.co.uk
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
simple SMPS ionutzxpo Power Supplies 38 22nd January 2013 01:53 PM
90v to 500v i\p sahu Power Supplies 1 18th November 2010 06:06 PM
Most compact 90V power supply jev Tubes / Valves 5 3rd December 2009 01:14 PM
really simple smps design? oldroborg Class D 10 30th August 2008 10:30 PM
simple smps east electronics Power Supplies 2 12th March 2006 04:21 PM


New To Site? Need Help?

All times are GMT. The time now is 06:27 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2