F5 power amplifier - Page 1257 - 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 27th August 2012, 06:41 AM   #12561
diyAudio Member
 
GentryBa's Avatar
 
Join Date: Oct 2011
Location: Bavaria
Quote:
Originally Posted by juma View Post
So everything is OK - you just can't expect the 25W amp to drive the speaker to same SPL as a 100W amp does.
Thanks, Juma!

So I think I was right with my assumption...
The sound was perfect and clear, only the bass wasn't as loud as on the 100W amps.
And that seems to be normal- it's only a quarter of the power....

If I put one MosFet parallel to the other, and raise the 590mV, maybe it would be a little bit better?
The PS ist well dimensioned (500VA and enough caps per mono side), so that shouldn't be the problem?

regards,
Matthias
  Reply With Quote
Old 27th August 2012, 07:04 AM   #12562
diyAudio Member
 
Join Date: Feb 2009
i have dual outputs and bias at 1.7A(400mV pr fet. so 800mV pr rail)
and that work very well on my scan-speak 3Way with dual 8" in the bottom.
and only 225VA and 74.000uF pr ch dissipation is about 86W at the sinks.
  Reply With Quote
Old 27th August 2012, 07:16 AM   #12563
diyAudio Member
 
GentryBa's Avatar
 
Join Date: Oct 2011
Location: Bavaria
Quote:
Originally Posted by AudioSan View Post
i have dual outputs and bias at 1.7A(400mV pr fet. so 800mV pr rail)
and that work very well on my scan-speak 3Way with dual 8" in the bottom.
and only 225VA and 74.000uF pr ch dissipation is about 86W at the sinks.

hi audiosan!

can you tell me, if its enough to put the output-mosfets parallel to the existing ones, without doubling the input parts or ztx devices?

THANK YOU!

regards,
matthias
  Reply With Quote
Old 27th August 2012, 07:49 AM   #12564
diyAudio Member
 
Join Date: Feb 2009
there is a little more to it. you dont have to do anything on the input.
but each output need there own source resistor and gate stopper.
Attached Files
File Type: pdf P-F5C-1V20-schematic.pdf (178.8 KB, 116 views)
  Reply With Quote
Old 27th August 2012, 08:06 AM   #12565
diyAudio Member
 
GentryBa's Avatar
 
Join Date: Oct 2011
Location: Bavaria
Quote:
Originally Posted by AudioSan View Post
there is a little more to it. you dont have to do anything on the input.
but each output need there own source resistor and gate stopper.

oh, sounds logical...

THANK YOU! I think, I have to do some work on my F5's the next weeks...

regards,
matthias
  Reply With Quote
Old 27th August 2012, 11:00 AM   #12566
diyAudio Member
 
Join Date: Feb 2009
the best way to do it, is to get the F5C boards from the store
and remember to set back the pots before start up
  Reply With Quote
Old 27th August 2012, 11:03 AM   #12567
diyAudio Member
 
Join Date: Feb 2009
here is the finnished board. without the fets.
Attached Images
File Type: jpg DSC00329.JPG (916.9 KB, 426 views)
  Reply With Quote
Old 27th August 2012, 11:32 AM   #12568
diyAudio Member
 
GentryBa's Avatar
 
Join Date: Oct 2011
Location: Bavaria
your parts are soooo nice, here in germany we only have the resistors with the coloured rings.

the F5c boards are to tall for my small enclosure...

they would be the best solution for upgrading- maybe I have to build another enclosure for it?

best regards,
matthias
  Reply With Quote
Old 27th August 2012, 11:43 AM   #12569
diyAudio Member
 
Join Date: Feb 2009
most of the resistors are from hi-fi collective 3w resistors are from RS
  Reply With Quote
Old 27th August 2012, 08:57 PM   #12570
diyAudio Member
 
Join Date: Aug 2012
Smile 67 year-old newbie begs for a little help !

Hi Gang: I'm a semi-retired recording engineer, pretty well-known around the old US of A. I've built a lot of stuff over the last 59 years, so have good construction knowledge and ability.

Problem: I've just joined the forum, and two nights ago I discovered the F5 build posts. I'm totally fascinated, and would like to build a couple of monoblock F5's.

25 watts is plenty, as I intend to use them with Wayne Parham's Pi-4's, which are very sensitive at 98 db or so.

The problem again: The info chain and posts have been going on for several years now, and it appears that build info is scattered among thousands of posts.

Is there someplace where the latest info, BOM and vendors can be found? The idea of culling several thousand posts to try to figure this out is a bit daunting, and I'll bet some of you have nailed this info and made it available easily. I'll order boards (which ones?) from the Store and sure will appreciate getting pointed in the right direction for info for a standard F5 build, BOM, and parts sources.

I sure hope that I'm not asking for too much, and many, MANY thanks for the help!

Jeff
  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 07:03 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