F5 power amplifier - Page 1001 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 19th January 2011, 05:48 PM   #10001
diyAudio Member
 
Join Date: Oct 2004
Location: Denmark
Quote:
Originally Posted by udailey View Post
How accurate is a fuse and what if one blows and the other one doesnt? Dunno if thats the answer. Maybe fast blow on AC but I dont see how you can purposely blow a fuse to protect a speaker against DC.. if thats the concern.
Thought the F5 current limiter was there to prevent the FETs from selfdestruction in case of shorts and other fault conditions. A fuse in the power rails would do the same thing, cut of the power once you reach a certain current level.
  Reply With Quote
Old 19th January 2011, 05:50 PM   #10002
diyAudio Member
 
bobodioulasso's Avatar
 
Join Date: May 2008
As this reliable amp accepts 2 ohms loads without burping and as i am wise enough not to short the outputs, i do not need current limiters.
If by chance i make a short, i am able to fix.
Those who intend to sell or give away their F5 have better to implement current limiting. One never knows what inexperimented users can do.


Edit : I fear fuses aren't fast enough

Quote:
what if one blows and the other one doesnt?
The F5 has the nice peculiarity not to show dc output when one rail is missing.

Last edited by bobodioulasso; 19th January 2011 at 06:04 PM.
  Reply With Quote
Old 19th January 2011, 06:11 PM   #10003
udailey is offline udailey  United States
diyAudio Member
 
Join Date: Mar 2008
Never employing speaker protection before I dont feel like I can keep up the conversation but seems to me that rail fuses are not the way to go. You need two and if both dont blow at same time it seems potentially dangerous. A current limiter wont stop DC.

EDIT I see your post Bobo. Well that is a nice feature
__________________
purchase LDRs anytime Also try my Resistor Replacers or LDR based Input Selector Email me. diyldr@gmail.com
  Reply With Quote
Old 19th January 2011, 06:17 PM   #10004
diyAudio Member
 
Join Date: Oct 2004
Location: Denmark
Quote:
Originally Posted by bobodioulasso View Post



The F5 has the nice peculiarity not to show dc output when one rail is missing.
Now thats a nice feature, if only a fuse was fast enough, then you would have your current limiter right there. Would make the board layout simpler.
  Reply With Quote
Old 19th January 2011, 06:40 PM   #10005
diyAudio Member
 
Bksabath's Avatar
 
Join Date: Dec 2007
IMO Current limiter to start with and then improve the sound quality by taking it off but IMO only if super duper protection is in place.

How much power dissipation needed for a mosfet to run EGG 4 A at 28V ???

agree enough heath to get rid off but maybe it could just sit on one corner all by itself.
Well maybe with the negative rail one just to keep it company

Neutrality yes it may be but then you have loads of energy stored in the caps

Is the may be that scare me.

Channel or washer yey by me Single srew on tab no so much
Big 5mm copper bar on top even beter but then I tend to complicate things.

If it works for one it works for them all
  Reply With Quote
Old 19th January 2011, 06:46 PM   #10006
diyAudio Member
 
Join Date: Oct 2004
Location: Denmark
Quote:
Originally Posted by Bksabath View Post

Neutrality yes it may be but then you have loads of energy stored in the caps
Fuse should be after the caps, fuse blows, connection gone, caps no longer connected to amp. Their energy storage doesnt matter in that case.
  Reply With Quote
Old 19th January 2011, 06:54 PM   #10007
diyAudio Member
 
Bksabath's Avatar
 
Join Date: Dec 2007
Tanks Neutrality

OK thats fine then

What the time response for the fuse say for example rated at 3A and the fault current is
say 30A ?
  Reply With Quote
Old 19th January 2011, 06:55 PM   #10008
diyAudio Member
 
Join Date: Oct 2004
Location: Denmark
Quote:
Originally Posted by Bksabath View Post
Tanks Neutrality

OK thats fine then

What the time response for the fuse say for example rated at 3A and the fault current is
say 30A ?
No idea, my fuse knowledge is nil.

But depends on type of fuse, fast or slow blow fuse and some other things

Last edited by Neutrality; 19th January 2011 at 06:59 PM.
  Reply With Quote
Old 19th January 2011, 07:00 PM   #10009
Kilroy is offline Kilroy  United States
diyAudio Member
 
Join Date: Feb 2010
Location: Austin, TX
Quote:
Originally Posted by udailey View Post
Not black oil but an oil based paint that is black. Well, thats Rod's information.. I just spit it back out here. He says black oil paint very very thin is the best but that anodizing is good to, you can see on his graphs. I would go for the anodizing option but then again you would still be buying a sink that cant compete with HS USA sinks. Honestly in the USA the HS USA guys have the best deal that I can find and the extrusion is made, in my opinion, especially for Pass DIY efforts. Its just my guess but I am betting Russel started his business to take care of us.
Copper spreads the heat the fastest but it doesnt like to LET GO of the heat. Aluminum spreads it pretty fast as well AND dissipates. Aluminum is best in a sink. You want to use a heat spreader? Probably copper is best but I would use some sort of thermal paste to help get the heat from the copper over to the aluminum and you will find folks telling you that copper on top of aluminum causes some sort of chemical reaction and I forget what else happens but two odd metals touching for a long time has some chemical reaction that has been discussed here before. I think if you use the paste you might not worry so much about this reaction.
Uriah

Edit: Oooooh we are creeping up on 10,000 posts!
Thanks for this!
So I'm sold on the HS USA sinks but I'm trying to figure out what length I need for each side of the stereo amps.
Do you guys think 8" is enough or do I need to go all the way to 12" like Labjr did?

Thoughts?
__________________
I made smoke!
  Reply With Quote
Old 19th January 2011, 07:40 PM   #10010
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by Bksabath View Post
How much power dissipation needed for a mosfet to run EGG 4 A at 28V ???
an IRF540 could easily cope with 10A @ 100mVds and also cope with turning that OFF to become 0A @ 30Vds.
It might not even need a heatsink.
It might need a separate higher voltage for the gate control.
__________________
regards Andrew T.
  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
Rockford Fosgate Power 20001 bd amplifier power rating?? pachoorion Car Audio 8 8th May 2011 10:49 PM
Power transformers versus amplifier output power..what is your option? destroyer X Solid State 38 9th May 2009 05:23 PM
McIntosh Power Amplifier Power Guard johnnyrt Solid State 2 23rd August 2007 10:22 PM
Output power for a power amplifier Progg70 Solid State 33 10th September 2006 08:44 AM
Amplifier 3000 Wats Rms Power + Smps Higcht Power Bestiality MARAVILLASAUDIO Class D 1 5th November 2004 04:06 PM


New To Site? Need Help?

All times are GMT. The time now is 01:41 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