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Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Fri Jan 04, 2013 2:39 am
by Dan
What ic are you using or have in mind mate? Fully solid state, class AB or class D?

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Fri Jan 04, 2013 7:56 am
by Fred
See first page :-)

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Fri Jan 04, 2013 1:37 pm
by Dan
Fred wrote:See first page :-)
ROFL! Sorry I must've missed that!

Ah the TDA7293 IC! Nice!

EDIT: Is your reason for using such that you have this IC already? or availability? or cost? etc?

The reason I ask is that I am doing some Class D work for a customer at the moment and you can get very efficient Class D IC's also! (less heat than AB for 100W, etc, etc)

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Fri Jan 04, 2013 5:12 pm
by Fred
I hate switchers for audio MUCH more than I hate them for power supplies in ECUs ;-)

Had three of them for months with intent to do just this.

Fred.

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sat Jan 05, 2013 11:37 am
by Dan
LOL @ hatred for switchers! :-)

makes me smile for so many reasons!

skype in a day or so eh?

:-)

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sat Jan 05, 2013 2:30 pm
by Fred
Skype complete! Skype again in ~24 hours :-)

Mean while, I cut the heatsink down to fit, and it's now 221mm long. So we have that much face for mounting boards to. I think the boards will purely be mounted to the heatsink, by IC and by some brackets. Each should be about 60 - 70mm wide for a bit of working space to be present for wiring, etc.

I need to cut some steel and plastic to get the heatsink into the part of the case that I want it. That and all of the other things on the list, too. Time to clean up the flat and do the dishes and some food shopping etc. Ahhhh chores.

Fred.

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sun Feb 03, 2013 2:36 am
by DeuceEFI
There is a picture of the first draft schematic for one channel amplifier IC.
git hash: 36c6a7f95121be5c332cde25fbff0e4994004703

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sun Feb 03, 2013 3:02 am
by DeuceEFI
github repository for the the amplifer PCB design:

https://github.com/DeuceEFI/Amplifier

git hash after adding the LICENSE.txt, TODO.md, README.md and Amplifier-Schematic.pdf files is: 3427d85e74e55b52c977fda8912b3612c0eaaec1

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sun Feb 03, 2013 2:39 pm
by Fred
I spy with my little eye a copy paste error in the readme ;-)

Haven't had a detailed look at the schem yet. I'll clone it in git and have a poke around.

Thanks! :-)

Re: Simple Cheap Compact IC-based High Performance Amp

Posted: Sun Feb 03, 2013 8:56 pm
by Fred
OK, I have it open in KiCAD and the basic layout looks good! I think. I'll recheck it when less tired, though.

Round one of minor changes:
  • Both 22uF caps are 100uF (C2 and C5)
  • Both upper and lower power supply have triple decouple + bulk (two missing caps per rail) (friends of C7 and C9)
  • The input cap (C1) is three 1uF caps in parallel, not one 0.47uF cap
  • The diode is 1N4007 (D1)
  • Standby and input grounds should be grouped as per PDF schematic (though yours is more clear! if we can maintain clarity, that'd be good!)
References:

http://stuff.fredcooke.com/TDA7293-AmpP ... icBase.png
http://stuff.fredcooke.com/TDA7293-AmpP ... otated.png (updated slightly to change maybes to yes/no)
http://stuff.fredcooke.com/amplifier.pr ... G_7001.JPG
viewtopic.php?p=30972#p30972

The vclip and input and mute/stby might need more stuff at some point, however I have no idea what, if anything, right now :-)

Fred.