diyAB Amp - The "Honey Badger" - Page 11 - 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 18th July 2011, 06:19 PM   #101
stoc005 is offline stoc005  United States
diyAudio Member
 
stoc005's Avatar
 
Join Date: Feb 2007
Location: Midwest in the USA
Default Std. Heatsinks??

With the different PCB output device layouts, is there any guidance as to a preferred heatsink?? I tend to like the Conrad single flange style but mounting them into a suitable chassis can be "interesting".
Mounting the outputs to an aluminum "L" bracket and bolting it to a flat heatsink is not optimal either, IMHO.
A large, flat heatsink does work for some the PCBs in this thread.
  Reply With Quote
Old 18th July 2011, 06:24 PM   #102
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Default Documentation

Quote:
Originally Posted by sonidos View Post
I also have the same flat packs (3281/1302) sitting here from a swap meet. Would be cool to use these OPS transistors in this project.

Variac and Ostripper, great idea. Very excited to try this!!
This is good.... What I need now is some suggestions on my Options/construction "manual". I just had someone that built my big "mongrel" (PB250 +AX= this amp ) , change some components to reduce total gain and produced an oscillator. I told him how to recompensate (increase input degeneration) for this or just attenuate the input signal. Someone else put semi's in backwards and let some magic smoke out . (all is "fixed" now )

For this kit , besides a VERY verbose BOM , A document (with diagrams) to guide even a first time builder from initial board stuffing right up to installing the final output devices. I have a technique that very few others use. Every amp I have built gets finished right up to the driver stage , then I use 2 X 10R safety resistors on the rails and split the driver emitter resistor in half (2 X 68R for this amp)hook the center point to the feedback resistor (output) and plug it in ! It will either read .5-.6V across the 68R's or magic smoke will erupt across the resistors. I HAVE HAD THIS HAPPEN ! BUT , never a blown semi.

The .5-.6V can then be adjusted to .59 - .6V ..... solder in a pair of outputs , turn the bias trimmer ... golden. Some have never assembled a kit or are familiar with JUST class A or tube tech ,a Class AB solid state should not be anything scary or intimidating - This amp is exactly 104 components - 232 "solderings" - a few more than a chip amp.

Please ... any suggestions on a comprehensive "manual" would be welcome. Any questions would be included in the manual ("newbie"/general type queries) ....

OS
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper
  Reply With Quote
Old 18th July 2011, 06:41 PM   #103
Banned
 
Join Date: Jan 2005
Making a foolproof manual is impossible. But make it as detailed as possible.

And put a big red warning on the front page saying "No component values can be changed in any way as it would hamper performance and possibly cause harm to product"

Frankly even i would need that manual since this thing is so complex compared to what im used to.
  Reply With Quote
Old 18th July 2011, 06:54 PM   #104
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Quote:
Originally Posted by stoc005 View Post
With the different PCB output device layouts, is there any guidance as to a preferred heatsink?? I tend to like the Conrad single flange style but mounting them into a suitable chassis can be "interesting".
Mounting the outputs to an aluminum "L" bracket and bolting it to a flat heatsink is not optimal either, IMHO.
A large, flat heatsink does work for some the PCBs in this thread.
TOTALLY universal ..." butt" the board up against any heatsink at a 90 degree angle -direct mounting. "L" bracket can work too. Flat mounting - no problem.
THIS will be the layout (below) - only this will be submitted to manufacture (eliminate confusion). L-K below are aligned with the universal Diyaudio drilling guide for their case and heatsinks. Main outputs align to the other holes in the drilling guide. The 3 smaller devices (q13-15) on the heatsink will have to be drilled additionally.
Board will be double-sided 2oz. FR-4 (no jumpers).

If Mark (variac) agree's , I will post the layout for prototypes. I have stared at this for a while and there is NO error (circuit vs. layout) .. all parts will fit with adequate clearance , as well.

OS
Attached Images
File Type: gif diyaampPCB.GIF (68.3 KB, 1962 views)
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper

Last edited by ostripper; 18th July 2011 at 07:04 PM.
  Reply With Quote
Old 18th July 2011, 08:44 PM   #105
diyAudio Member
 
Join Date: Nov 2010
Location: Marblehead Ma
10" x 3" perfect . that will JUST fit on a slice of 10.080" - HeatsinkUSA, LLC Store which is an absolute bargain for folks in the usa .

i'm using 7" tall slices on my F5 and they barely get warm .

cheers Woody
  Reply With Quote
Old 19th July 2011, 01:09 PM   #106
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I too advocate the small loop area of the power input traces.
I add that the "Power" supply must include the Power Zero Volts.

The triplet of +ve, Zero Volts, -ve virtually cancel. Do this for both the twisted triplet power cable and for the paralleled traces on the PCB. And keep the Spkr output terminal very close to the power input triplet terminals, post74 shows this 4 terminal group.
__________________
regards Andrew T.

Last edited by AndrewT; 19th July 2011 at 01:28 PM.
  Reply With Quote
Old 19th July 2011, 04:26 PM   #107
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Quote:
Originally Posted by AndrewT View Post
I too advocate the small loop area of the power input traces.
I add that the "Power" supply must include the Power Zero Volts.

The triplet of +ve, Zero Volts, -ve virtually cancel. Do this for both the twisted triplet power cable and for the paralleled traces on the PCB. And keep the Spkr output terminal very close to the power input triplet terminals, post74 shows this 4 terminal group.
Your wish is my command .... ADCOM does it (below 1) , can't argue that fact. IN FACT , I always did agree that the science supports this as the optimum layout scheme. No argument there. So , this may take another few hours (Below 2) , but (small loop area , triplet , asymmetrical layout) will be the way.
Even as I thank Alex for that layout (post 74) , it is not applicable to the style that DIYA wants. Adcoms style is more in line with what is desired.
(almost)DONE - FIXED.

OS
Attached Images
File Type: gif adcom535.gif (52.8 KB, 1834 views)
File Type: gif newdiyaamp.GIF (25.6 KB, 1763 views)
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper
  Reply With Quote
Old 19th July 2011, 05:11 PM   #108
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Yes and the MF & HF decoupling become much more effective.
The previous layout had an enormously long loop around the output devices and the HF decoupling ~500mm long.

I accept that DIYaudio guidance for a universal board will over-ride these layout ideas and I cannot and will not object if OST has to revert to previous to solve all the layout details.

Thanks to OST for all this great work.
__________________
regards Andrew T.
  Reply With Quote
Old 19th July 2011, 05:36 PM   #109
diyAudio Member
 
ostripper's Avatar
 
Join Date: May 2008
Location: Albany , NY (smallbany)
Quote:
Originally Posted by AndrewT View Post
Yes and the MF & HF decoupling become much more effective.
The previous layout had an enormously long loop around the output devices and the HF decoupling ~500mm long.

I accept that DIYaudio guidance for a universal board will over-ride these layout ideas and I cannot and will not object if OST has to revert to previous to solve all the layout details.

Thanks to OST for all this great work.
Thank you , for quieter amps . Look below , would "K" as chassis ground be prudent coming into the main star. Note the 2 reservoir grounds and the small signal ground coming in from the left. Please comment on this.
All are labeled (temporarily).
I can do this ... in fact, easily Even keeping the "DIYA guidance" aspect. I want the best - any cost !
PS - you can reach a screwdriver past the large caps to access the semi's now ...

OS
Attached Images
File Type: gif grounding.GIF (33.1 KB, 1702 views)
__________________
Mongrel website , always current and updated :
http://www.fidelityforce.com/ostripper

Last edited by ostripper; 19th July 2011 at 05:38 PM.
  Reply With Quote
Old 19th July 2011, 05:44 PM   #110
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
The two reservoir grounds must be connected together before connecting to the Main Audio Ground (MAG).
The new layout will send a proportion of the cap charging pulses across the MAG and contaminate the spkr signal. If this on board reservoir is the sole smoothing after the rectifiers then this will be disastrous.
The new HF decoupling will be just as bad as the previous.
The HF decoupling must be located at the output devices and connect to each other via the shortest possible loop. That common Power Ground is then routed to the MAG.
The power should come into the fuses and go to the reservoirs. Then from the reservoirs to the Drain feeds. The reservoirs must not tap off the fuse to Drain feeds.
Do we really want/need the Thiele L//R on board?
Diodes from -ve to Zero Volts to +ve help prevent damage if the PSU is inverted. They also limit reverse voltage on the reservoirs to <=700mV if a fault develops that discharges one supply rail.
Are the two existing diodes the output to rail limiters? I note the connected one is rail to rail !
__________________
regards Andrew T.

Last edited by AndrewT; 19th July 2011 at 05:51 PM.
  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
diyAB Amp The "Honey Badger" build thread Variac Solid State 1150 2nd July 2014 11:45 AM
Honey, I smoked the Weller 8200 jackinnj Equipment & Tools 5 25th April 2011 06:07 AM
Badger Badger Badger..... Mushroom !! 5th element Everything Else 15 20th September 2003 03:16 PM


New To Site? Need Help?

All times are GMT. The time now is 12:47 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