Simple Symetrical Amplifier - Page 152 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 26th November 2011, 08:43 PM   #1511
diyAudio Member
 
Idefixes's Avatar
 
Join Date: Dec 2003
Location: Mulhouse - Alsace
Send a message via ICQ to Idefixes
Quote:
Originally Posted by tinitus View Post
ah, that is different, and clever

it is really very effective to have the heatsink go through bottom and top

I have experienced problems when having trafo close to input
but I guess your heatsink shields it nicely
The schielding is not provided by the heatsink but by a 2mm thick steel sheet that is placed between trafo an heatsink and that is connected to ground. This steel sheet goes from bottom to case top.

Marc
__________________
website : http://audiyofield.wifeo.com/index.php
  Reply With Quote
Old 27th November 2011, 12:39 AM   #1512
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Quote:
Originally Posted by Idefixes View Post
LC will you share your routing job ...

Marc
Just a little for a taste ... with Alex's permission hehe
Attached Images
File Type: jpg SSA BIGBT HP Photo.jpg (747.9 KB, 589 views)
  Reply With Quote
Old 27th November 2011, 06:50 AM   #1513
diyAudio Member
 
SOUND_Rays's Avatar
 
Join Date: Mar 2009
Thumbs up Duo Masters of purest Audio science of Art

Quote:
Originally Posted by Lazy Cat View Post
Just a little for a taste ... with Alex's permission hehe
Wow, what a beauty of pure Audio Art

Congratulations to both of You

Mr. Andrej for this genie beauty - Diamond,

and

Mr. Alex for Yours beautifully mastered painting of it.

The pure duo virtuoso masters of art.

-----------------------------------------------------------------------------------------------------------------
LC, Have You maybe just take a look to post #1492 and quick look to a SCH Image and possibly confirm it?

Thank You,

  Reply With Quote
Old 27th November 2011, 02:49 PM   #1514
diyAudio Member
 
Join Date: Feb 2011
Location: Devon, UK
Quote:
Originally Posted by Idefixes View Post
Good news : the NJL4302DG i was wating for are under way. My ThermalTrack version will use couple of NJL4281DG/NJL4302DG. I put you under the latest pcb version board. Don't hesitate to comment It.
I like very much. Just a couple things. Would it be possible to replace the output resistors (5 pairs) with a short length of straight nichrome wire? And how do you envisage connecting the output transistors to the heat sink? Would it be better to mount them off the board (hanging over the edge?).
What about splitting the power supply, so that just the output transistors are fed by a separate high power version, and the rest of the circuit fed off the on board?

I want to build them as two monoblocs, any problems you see with that?
regards
Bryan

Last edited by cats squirrel; 27th November 2011 at 03:14 PM.
  Reply With Quote
Old 27th November 2011, 03:31 PM   #1515
diyAudio Member
 
Idefixes's Avatar
 
Join Date: Dec 2003
Location: Mulhouse - Alsace
Send a message via ICQ to Idefixes
Hi bryan,

I don't understand all what you say. What do you mean by "short length of straight nichrome wire"?
This project as for to goal to test SSA topology for sound evaluation in a simple compact form. This pcb board was developped according to my specifics requierements (as to use my 330va2x25V trafo, my screw 22.000f/40v smoothing caps, Mur1560 rectier diode, 195x150x27mm heatsink...). As i said above the form must be as compact as possible (250x250x200mm at this time). Due the simplicity i expect i don't want to split Output power stage and imput power stage. This will the subject in a SSA High perf. version (BIGBT normally). In my pcb board Output device are mounted under board. If you take a look to previous case sketch you can have an idea of my project.

Marc
__________________
website : http://audiyofield.wifeo.com/index.php
  Reply With Quote
Old 27th November 2011, 04:53 PM   #1516
diyAudio Member
 
Join Date: Feb 2011
Location: Devon, UK
Hi Marc

nichrome wire is made of Nickel and Chromium, and has a relatively high resistivity, and therefore resistance, depending on diameter.
Look here for typical values: wires.co.uk : Bare Nickel Chrome / Nichrome Section

I think I am correct in thinking the output resistors should be non inductive? so typical wire wound resistors are not appropriate, but straight short pieces of nichrome would be perfect.

Will you be making the pcb's available for others?
  Reply With Quote
Old 27th November 2011, 05:05 PM   #1517
diyAudio Member
 
Idefixes's Avatar
 
Join Date: Dec 2003
Location: Mulhouse - Alsace
Send a message via ICQ to Idefixes
The fact of replacing the one 0r22 5W by five 1r2 1w is due to the fact that i have difficulties to find localy 0r22 5W non inductive resistor, so if your Nichrome wire is non inductive and you can achive 0R22 (you will need to mesure the resistance value with an another methode than DMM since they completely out of value with small value) that go for. If some is interested i will share, only for DIY destination, my work since it is based on others work (LC and alex_mm) and its for me only a hobby. But all that work need to be tested for eventually debuging.

Marc
__________________
website : http://audiyofield.wifeo.com/index.php
  Reply With Quote
Old 27th November 2011, 07:31 PM   #1518
diyAudio Member
 
Lazy Cat's Avatar
 
Join Date: Sep 2007
Exclamation SSA BIGBT HP PCB LAYOUT Optimization

Quote:
Originally Posted by tinitus View Post
... but strangely, lately I see more and more members place the output devices in a way that doesnt seem to make very good use of the heatsink
and even the most experienced ones
things like having outputs at the very top of a heatsink
and I really hate when you cant turn a board 180degr, without ending up with long wires etc
sometimes its like only designing a board fore the left channel, and forgetting how both channels look when mounted
stuff like power supply connection, signal wires etc

seems like a matter of not having patience and time to think it all through, very carefully
why such hurry ?
Hi tinitus

No hurry here, the more time we spend, the more quality we get, usually. So I prepared completely new PCB layout proposal according to some remarks, which brings:

- smaller PCB dimensions of only 120 mm x 170 mm
- shorter tracks, more HF ready, very-high speed design
- output transistors in the middle, better heat spread to the centre of the heatsink
- before free area above output transistors is now used for the parts,
- optimization of the board space makes more dense population, more compact PCB
- grid is 1 mm x 1 mm and shows 0,5 mm accuracy of parts placing on the layout
- there are 7 fixation M3 holes
- there are 10 through PCB holes of 6,5 mm diameter
- double layer 2 mm thick PCB

In the pic you can see the "working design" in a phase before Alex gets it to his "hands". Can be educational to some DIY newbies.

Regards, Andrej
Attached Images
File Type: jpg SSA BIGBT HP PCB LAYOUT.JPG (386.3 KB, 493 views)
  Reply With Quote
Old 28th November 2011, 01:12 AM   #1519
Bigun is offline Bigun  Canada
diyAudio Member
 
Bigun's Avatar
 
Join Date: Jan 2009
Blog Entries: 2
I like the spkr output positioned like my TGM5 pcb, looking nice!
__________________
"The test of the machine is the satisfaction it gives you. There isn't any other test. If the machine produces tranquility it's right. If it disturbs you it's wrong until either the machine or your mind is changed." Robert M Pirsig.
  Reply With Quote
Old 28th November 2011, 02:27 AM   #1520
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by Lazy Cat View Post

In the pic you can see the "working design"

Regards, Andrej



120mm fits perfekt in a modu 4U/300 with 165mm internal height, giving a nice chunky look
and those heatsink should make it indestructable in any load
  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
Symetrical schematics are alike plague in Brazil, do you like them? destroyer X Solid State 151 1st July 2010 02:09 PM
Symetrical out low Zout karsten21 Tubes / Valves 5 1st February 2010 10:19 PM
going balanced/symetrical - what benefits? weissi Solid State 15 20th October 2007 08:06 AM
Symetrical field, is this? Raka Multi-Way 6 14th September 2003 01:21 PM
Non-symetrical SMPS output cm961 Parts 4 21st August 2003 10:27 PM


New To Site? Need Help?

All times are GMT. The time now is 03:25 AM.


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