F5 power amplifier - Page 511 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 7th October 2009, 03:46 AM   #5101
jleaman is offline jleaman  Belgium
Join Date: Apr 2002
Send a message via AIM to jleaman
Originally Posted by thanh1973 View Post
Two Pack Epoxy
  Reply With Quote
Old 7th October 2009, 05:11 AM   #5102
Join Date: Nov 2006
Have you tried it?
This is what all the manufacturers use.

If you want better then polyurea or polyurethane would be better. If you want to improve on that then fill it with very dense pigments.
  Reply With Quote
Old 7th October 2009, 07:47 AM   #5103
diyAudio Member
bobodioulasso's Avatar
Join Date: May 2008
I have poted one into an aluminium pan using silicone. That made it silent but i do not know about the long time.
  Reply With Quote
Old 7th October 2009, 08:58 AM   #5104
Join Date: Nov 2006
Silicone has some nice properties, as good as or possibly better than polyurethane
  Reply With Quote
Old 7th October 2009, 09:09 AM   #5105
diyAudio Member
bobodioulasso's Avatar
Join Date: May 2008
Heat sinking might be an issue?
It coud become a torrid transformer.
  Reply With Quote
Old 7th October 2009, 09:13 AM   #5106
AuroraB is offline AuroraB  Norway
diyAudio Member
AuroraB's Avatar
Join Date: May 2001
Location: Norway, -north of the moral circle..
For potting a transformer, use the special compounds developed for potting- available from most professional parts suppliers, an nusually not more expensive than the amount of epoxy required.

Vacuum impregnating the core/windings of a trafo is something else - this is done with very low viscosity laquers to get into the windings. Can't be done with normal potting compounds....
While the Lie leapt from Bagdad to Constantinopel, the Truth was still looking for it's sandals!
  Reply With Quote
Old 7th October 2009, 02:35 PM   #5107
diyAudio Member
Join Date: Jun 2005
Location: Massachusetts
Labjr: Which transformer are you using?


The Avel 250va 18v + 18v dual secondaries. It had been working fine. The same transformer in the other monoblock is working. I do have a very slight hum in that speaker, but it doesn't change when the transformer starts making the noise. Thanks for your repllies. Even with this problem the F5 is performing very nicely.
  Reply With Quote
Old 7th October 2009, 06:30 PM   #5108
labjr is offline labjr  United States
diyAudio Member
Join Date: Apr 2003
Location: MA
Does one chassis buzz more than the other one if you put your ear to it?

I don't know if a noisy transformer will make a hum through the speaker. Maybe someone else can answer this.
  Reply With Quote
Old 7th October 2009, 06:43 PM   #5109
diyAudio Member
Join Date: Jun 2005
Location: Massachusetts
Just the one transformer buzzes. I can hear it faintly from 3 feet away. And that unit's speaker has a very minor hum that I can only hear withmy ear on the thing and I hear it from start up. The transformer develops the buzz an hour after startup. The other monoblock makes no chassis noises and the speaker is perfectly quiet.

About this time I did do a mod on my cd player. Bypassed the output caps per Kit Ryan's .
suggested mods in Audio xpress. Could this be related? Cd is attached to B1 that is attached to F5. Thanks for help.
  Reply With Quote
Old 7th October 2009, 07:28 PM   #5110
tinitus is offline tinitus  Europe
diyAudio Moderator R.I.P.
Join Date: Nov 2005
You could try disconnect your signal/B1, to see if it still hums
Or reverse channels from your signal/B1, to see if it follows signal
Also examine if wireing is slightly different on left/right channel

Your hum and buzz might still be two different things
Nelson have said that hum might be an indication of minor instability
And that it may be related to signal wire/grounding

As said earlier, even the slightest transformer buzzing can be "amplified" by the enclosure, and sound much worse
Without the box you might not hear anything

edit, do your supply caps get hot ?

Last edited by tinitus; 7th October 2009 at 07:35 PM.
  Reply With Quote


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 11:32 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2