F5 power amplifier - Page 551 - 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 1st November 2009, 11:25 PM   #5501
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Careful, it may be a bit tricky to assemble, and do work on
Takes practice

Anyway, a very tall box design with F5 would result in the upper half of the box being empty, which seems like waste to me

Last edited by tinitus; 1st November 2009 at 11:31 PM.
  Reply With Quote
Old 2nd November 2009, 09:23 AM   #5502
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by generg View Post
I like the sound of the F5 without current limiter more, may be because my Thiel SCS 4 has only 4 Ohm.
But my current is going up and up, slowly but sure. Will be there a stop? Or is it impossible to get a balance?

Oh I forgot I put away the thermistors too!
the current limit is set too low for 8ohm speakers played loud.
It is far too low for 4ohm speakers played loud.

If your amp blows up, or takes out your speakers, because you deleted the thermistors, then you deserve all you get.
__________________
regards Andrew T.
  Reply With Quote
Old 2nd November 2009, 01:06 PM   #5503
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by AndrewT View Post

If your amp blows up, or takes out your speakers, because you deleted the thermistors, then you deserve all you get.
A bit harsh I would say

Anyway, with multiple output devices I suppose theres no need to worry
  Reply With Quote
Old 2nd November 2009, 01:45 PM   #5504
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Anyone know if the Large gold heat sinks over on the Apex thread in vendors forum would work for F-5?

Russellc
  Reply With Quote
Old 2nd November 2009, 02:19 PM   #5505
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Russell,

if you mean the $20 each RF heatsink, the best you can expect is 0.50C/W

Or 2 times 0.60C/W, the equivalent of 0.30C/W, if you saw the goldy locks in half.
The densely spaced ribs make it a low efficiency heatsink for heights above 6"

Last edited by jacco vermeulen; 2nd November 2009 at 02:22 PM.
  Reply With Quote
Old 2nd November 2009, 02:23 PM   #5506
diyAudio Member
 
vdi_nenna's Avatar
 
Join Date: Oct 2000
Location: PA, USA
Blog Entries: 1
Send a message via Yahoo to vdi_nenna
Quote:
Anyone know if the Large gold heat sinks over on the Apex thread in vendors forum would work for F-5?
Yes they will. Use 2 per channel.
Attached Images
File Type: jpg F5build4.JPG (96.2 KB, 688 views)
__________________
I build, therefore I am.
  Reply With Quote
Old 2nd November 2009, 04:12 PM   #5507
sekess is offline sekess  United States
diyAudio Member
 
Join Date: Feb 2006
Location: NJ
Default Chokes mounting in CLC power supply

I am using some Hammond 159ZL chokes for the CLC power supply. With air core inductors I have read that the inductors should be mounted as far away from each other as possible (and/or at 90deg angles to each other) to minimize magnetic coupling.
When using the iron core Hammond chokes, is mounting proximity still an issue? Or, is it not that significant since more of the magnetic field will be concentrated atthe iron core?

Thanks,
Steve
  Reply With Quote
Old 2nd November 2009, 04:21 PM   #5508
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
 
Join Date: Nov 2005
Quote:
Originally Posted by vdi_nenna View Post
Yes they will. Use 2 per channel.
They are 170x250mm
Yes, 2 pr channel ought to work
I would prefer more like 4 pr channel
But will it still be a bargain?

Last edited by tinitus; 2nd November 2009 at 04:34 PM.
  Reply With Quote
Old 2nd November 2009, 05:45 PM   #5509
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Quote:
Originally Posted by AndrewT View Post
the current limit is set too low for 8ohm speakers played loud.
It is far too low for 4ohm speakers played loud.

If your amp blows up, or takes out your speakers, because you deleted the thermistors, then you deserve all you get.
I trust in God and Nelson Pass:
The circuit of Figure 5 illustrates the basics and does in fact work, but has a tendency toward instability ...and the bias drifts with temperature, requiring a lengthy adjustment period.
.... This allows adjustment of the output stage bias current and also the output DC offset.
We can stop here, and the amplifier will be fully functional. The remaining additions will enhance temperature tracking and provide for output current limiting.
  Reply With Quote
Old 2nd November 2009, 06:30 PM   #5510
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by generg View Post
has a tendency toward instability ...and the bias drifts with temperature,
if the heatsinking is marginal or the ambient temperature rises then the thermistors are no longer optional.

If the heatsinking is designed for worst case condition as Pass would do, then the stability with temperature brought about by adopting the full thermistor compensated circuit is neither a problem nor a necessity , just a time saving exercise.
__________________
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 09:59 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