Potting transformers - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 26th November 2002, 12:35 PM   #1
diyAudio Member
 
Join Date: Nov 2002
Default Potting transformers

I have seen many designs that show potted transformers and have often wondered if their is any sonic benefit to doing it or was it just to make a unit appear more pleasing to the wife/girlfriend. In any case can someone go thru the proper procedure for potting one's own transformers? What is used for potting material? Geez this is starting to sound like a gardening post. At any rate... any information will be appreciated as usual.

Thanks
Joe
  Reply With Quote
Old 26th November 2002, 01:02 PM   #2
diyAudio Member
 
Join Date: Mar 2002
Location: CROATIA
Hello burnedfingers,

Potting the transformer is not hard to do.
If potting the transformer done properly,
it can lower the buzzing noise of the transformer.
But, if you damage the transformer, it will be very hard
or even unpossible to repair it, as the resin will become
rock-solid.

You can use two types of resin for this job.
Polyester and Epoxy.
Polyester is very cheap, and it can have fast setting time.
But, it have smell like in hell, can generate a lot of heat,
and after setting it can shrink a bit.
The more better resin is Epoxy.
It do not smell, setting time is much longer (30 min-24 h),
depending on resin type, and there is no that much shrinkage.
The good epoxy resin is CIBA and LF.

Also you can add some paste color to the resin if you would
like the color it.
Be aware that the some colors can't be mixed with the both
resins, and before you use them, you should check it for which
type of resin it is.

Be carefull, once when you pott the transformer, there is no
way for comeing back, so you should done it properly from the
first time.


Best regards,
Kristijan Kljucaric
http://web.vip.hr/pcb-design-vip
  Reply With Quote
Old 26th November 2002, 01:48 PM   #3
JohnG is offline JohnG  United States
diyAudio Member
 
Join Date: Mar 2002
Location: Upstate NY
Default RTV potting

Another possibility is RTV potting materials. I came across these when I was looking for thermlly conductive adhesives.

I only have limited experience with RTV, but you will want either heat-cured or 2-part RTVs. One source to check is

www.mgchemicals.com

which are sold by Allied Electronics.

I have only worked with non-flowable RTVs which are not very suitable for potting, but flowable ones exist for this purpose.

At least some RTVs can be removed with a lot of work.

John
  Reply With Quote
Old 26th November 2002, 05:25 PM   #4
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default MIND WHAT YOU DO...

Hi,

Assuming you are all talking about power Xformers,keep in mind that some are running pretty hot and when potted they can short internally.

Nerver pot an OPT unless you really know what you're doing.
If not you risk to alter it's frequency response due to added stray capacitance.

See also:

neophyte - transformer potting

And page three of this link:

Your thoughts please

Ciao,
__________________
Frank
  Reply With Quote
Old 26th November 2002, 11:06 PM   #5
dice45 is offline dice45  Germany
diyAudio Member
 
Join Date: Jan 2002
Location: Munich, Bavaria
Joe,

please avoid potting and potted stuff for potting's sake, makes the trannie expensive and does not gain you anything but a pot looking nice until the lacquer splints off..
Please follow the links Frank gave.
I jut found that Brett bets that i sell my potted Tango after i compared it to the Lundahl.

I don't hold that bet. Wouldn't i be quite optimistic the unpottend but resin-soaked Lundahl outperforms the Tango, i would not order it for tryout, i am pretty short of money. And i have the Tango already.

Now if a potted iron A happens to sound better than an unpotted iron B, that's a reason to keep that particular iron or maybe even swallow the toad of an elevated price.
__________________
Greets,
Bernhard
  Reply With Quote
Old 27th November 2002, 12:39 AM   #6
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default SCREENING,POTTING

Hi,

It wouldn't come as a surprise to that the unpotted Lunddahls would sound more "open" than the potted Tangos.
Even when both frequency plots do not indicate major deviations in the HF response.

Those of you that listened to a screened versus unscreened I/C may have a feel for what I mean here.

Strange but often true.

Ciao,
__________________
Frank
  Reply With Quote
Old 27th November 2002, 12:05 PM   #7
diyAudio Member
 
Join Date: Nov 2002
Thanks for the information. I won't pot the transformers or chokes. What if I just make a nice cover that doesn't touch the transformer or choke and mount it so it hide them and looks wife friendly?

Joe
  Reply With Quote
Old 27th November 2002, 12:07 PM   #8
diyAudio Senior Member
 
fdegrove's Avatar
 
Join Date: Aug 2002
Location: Belgium
Default POTTER.

Hi,

Quote:
What if I just make a nice cover that doesn't touch the transformer or choke and mount it so it hide them and looks wife friendly?
Nothing against that I suppose.

Cheers,
__________________
Frank
  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
Toroidal transformer potting can jamesjung21 Tubes / Valves 13 20th February 2008 01:04 PM
Transformer potting material?? ThSpeakerDude88 Tubes / Valves 9 6th August 2006 11:14 PM
Potting and sheilding transformers pjpoes Parts 1 8th March 2005 08:58 PM
neophyte - transformer potting ofb Tubes / Valves 13 13th December 2004 10:03 AM
Old Tranny Potting Material audiopro Tubes / Valves 6 8th June 2004 11:27 AM


New To Site? Need Help?

All times are GMT. The time now is 10:00 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