LM1875 PCB, Which To Use - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Chip Amps

Chip Amps Amplifiers based on integrated circuits

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 3rd April 2008, 08:30 AM   #11
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Not a problem, need to take a drive to the PCB factory quickly, but when I get back I will prepare and post it for you.
  Reply With Quote
Old 3rd April 2008, 08:57 AM   #12
Paswa is offline Paswa  India
diyAudio Member
 
Paswa's Avatar
 
Join Date: Aug 2007
thanks nordic, thank you very much , please try to do it a little quickly,,I'm just can't wait anymore to build the 1875 chipamp and to enjoy my favourite musics. I know you'll do for me.

And, what about my PCB? is there any mistake? that you found?
  Reply With Quote
Old 3rd April 2008, 09:45 AM   #13
Paswa is offline Paswa  India
diyAudio Member
 
Paswa's Avatar
 
Join Date: Aug 2007
Is the circuit of the PCB is 5 all right ? http://www.diyaudio.com/forums/attac...amp=1201427555
  Reply With Quote
Old 3rd April 2008, 10:09 AM   #14
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Is it possible to move the resistors pictured, just a bit farther away from the power caps?
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 3rd April 2008, 10:59 AM   #15
diyAudio Member
 
Greg Erskine's Avatar
 
Join Date: Jan 2002
Location: Sydney/Australia
Quote:
Originally posted by danielwritesbac
Is it possible to move the resistors pictured, just a bit farther away from the power caps?
Yes.
__________________
Greg Erskine
  Reply With Quote
Old 3rd April 2008, 02:17 PM   #16
BWRX is offline BWRX  United States
diyAudio Moderator Emeritus
 
Join Date: Jan 2005
Location: Pennsylvania
Default Re: LM1875 PCB, Which To Use

Quote:
Originally posted by Paswa
There are many PCBs. But what to use?
What are your soldering skills like? Do you plan on making your own boards or having a board house make them? The answers to those questions will narrow down your choices...

Quote:
Originally posted by Paswa
I made a PCB of 1875 toooo...see it
So why not just use your own design and see how it works? That will probably sound better to your ears than any other design
__________________
Brian
  Reply With Quote
Old 3rd April 2008, 02:48 PM   #17
Nordic is offline Nordic  South Africa
diyAudio Member
 
Nordic's Avatar
 
Join Date: Sep 2005
Absolutely Brian, I think your SMD boards are realy cute

Click the image to open in full size.

What do you guys think about this layout then?

W=60.6225mm x H=51.744mm (2.4"x2.1")

I am tempted to add the PSU to the boards, it makes life so much easier, less wires, less drilling etc.. and a cleaner look when installed, only requires a transformer ad the 2 boards in the case.
  Reply With Quote
Old 3rd April 2008, 07:47 PM   #18
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
What would this one:
http://www.diyaudio.com/forums/attac...amp=1201427555
look like without the fuses?

I like it best because it has significant room between power and signal components, and because it can connect a wide variety of input filter cap sizes.
See, on the picture, if a poly input cap is wanted, then the input terminal can be omitted. That option makes room a variety of sizes, so it would be nice to have that option.

Speaking of SMD, howabout make the feedback resistor SMD? The back two pins of LM1875 are extra long, and I think that an SMD resistor just fits there. My only problem with going entirely SMD is (|00...0>^6 + |11...1>^6)*2, which will have stolen some of them.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 4th April 2008, 09:37 AM   #19
Paswa is offline Paswa  India
diyAudio Member
 
Paswa's Avatar
 
Join Date: Aug 2007
I'll request nordic to share the eagle .brd file of the PCB with me, if possible..

And this is the PCB I designed without fuses,, is tyhere any error??
Attached Images
File Type: gif pccccb.gif (35.3 KB, 3152 views)
  Reply With Quote
Old 4th April 2008, 11:32 AM   #20
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Perhaps I would do this instead.

Center pin of LM1875 is -v

And, I'd move that 1m slightly farther from the power caps.

Terminal blocks can have the wires come loose, so I'd just omit it.

EDIT: Oops, however, I wouldn't increase the distance on the NFB resistor's leads like that picture. Sorry about that.

EDIT2: Um, those cap values.
Okay, the 22uF at NFB would be a 100v model, and then the 2.2uF at Input, should, instead, be 1uF polypropylene, like a Wima 100v MKP, which is rectangular.
IF, however, the input filter cap is supposed to be electrolytic, it would be 4.7uF (or 3.3) and the NFB cap would be 47uF.
Attached Images
File Type: jpg lm1875edit.jpg (90.7 KB, 3028 views)
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  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
LM1875...how low can you go? Gcollier Chip Amps 7 6th May 2010 04:43 AM
How hot does an LM1875 get? Dominique Chip Amps 15 23rd January 2007 03:13 AM
lm1875 siemensc65 Chip Amps 4 23rd May 2006 04:28 AM
Lm1875 soundNERD Chip Amps 14 12th October 2003 03:26 AM


New To Site? Need Help?

All times are GMT. The time now is 06:16 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