Rubber washers on TRANSFORMERS???

kyrie48 · 6th November 2007, 03:26 AM

I just put rubber washers between the case and transformer in several amps I have. Most are vintage with slightly more buzz/vibration than new ones, and this really helped solve the problem.

NOW, question is; have I created a problem with grounding, or anything I'm not thinking of???

TTYL, kyrie

Conrad Hoffman · 6th November 2007, 03:42 AM

The transformer cases still need to be grounded for safety reasons, but IMO transformers vibrate and there's nothing wrong with a little isolation so the rest of the amp doesn't act like a soundboard. I'd just use a couple ring lugs and a short loop of heavy wire for grounding.

Gordy · 6th November 2007, 09:21 AM

I think there was some discussion of this over in the Tubes section of the forum. Might be worth a search over there...

jaycee · 6th November 2007, 12:24 PM

I'm assuming you mean EI type transformers.

If the transformers are bolted down to the chassis, with just a rubber insulator between the base of the transformer and the chassis, then they will still be electrically connected via the bolts. You may want to add some toothed washers just to make sure. Check with a resistance meter and you will probably find the casings are still earthed.

kyrie48 · 7th November 2007, 06:41 AM

Sorry, should've been more specific... I put washers between the transfomer and amp, but no washer on the bolt. I was afraid that might really ruin my day!!
But was still concerned this might not be proper... looks like makers would do this from the factory. But, I guess they hope stuff is replaced before there's any issues with such.

That cures all my ills about mounting... huge help. Thanks ALL!!
TTYL, kyrie

taj · 9th November 2007, 08:16 PM

And for toroidal transformers I throw away the wimpy thin rubber rings that usually come with them and cut out rings of flat thin (1/8" or whatever) high-density packing foam (either styro or rubber) before tightening it down. No chance of any buzzes or rattles, and it keeps the transformer very stationary.

We have an excess of this type of scrap material at my workplace, so it's easy for me to get.

..Todd

6th November 2007, 03:26 AM	#1
kyrie48 diyAudio Member Join Date: Aug 2006	Rubber washers on TRANSFORMERS??? I just put rubber washers between the case and transformer in several amps I have. Most are vintage with slightly more buzz/vibration than new ones, and this really helped solve the problem. NOW, question is; have I created a problem with grounding, or anything I'm not thinking of??? TTYL, kyrie

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6th November 2007, 03:42 AM	#2
Conrad Hoffman diyAudio Member Join Date: Mar 2007 Location: Canandaigua, NY USA	The transformer cases still need to be grounded for safety reasons, but IMO transformers vibrate and there's nothing wrong with a little isolation so the rest of the amp doesn't act like a soundboard. I'd just use a couple ring lugs and a short loop of heavy wire for grounding.

6th November 2007, 09:21 AM	#3
Gordy diyAudio Member Join Date: Nov 2006	I think there was some discussion of this over in the Tubes section of the forum. Might be worth a search over there...

6th November 2007, 12:24 PM	#4
jaycee diyAudio Member Join Date: Apr 2004 Location: Norwich, UK	I'm assuming you mean EI type transformers. If the transformers are bolted down to the chassis, with just a rubber insulator between the base of the transformer and the chassis, then they will still be electrically connected via the bolts. You may want to add some toothed washers just to make sure. Check with a resistance meter and you will probably find the casings are still earthed.

7th November 2007, 06:41 AM	#5
kyrie48 diyAudio Member Join Date: Aug 2006	Sorry, should've been more specific... I put washers between the transfomer and amp, but no washer on the bolt. I was afraid that might really ruin my day!! But was still concerned this might not be proper... looks like makers would do this from the factory. But, I guess they hope stuff is replaced before there's any issues with such. That cures all my ills about mounting... huge help. Thanks ALL!! TTYL, kyrie

9th November 2007, 08:16 PM	#6
taj diyAudio Member Join Date: Feb 2005	And for toroidal transformers I throw away the wimpy thin rubber rings that usually come with them and cut out rings of flat thin (1/8" or whatever) high-density packing foam (either styro or rubber) before tightening it down. No chance of any buzzes or rattles, and it keeps the transformer very stationary. We have an excess of this type of scrap material at my workplace, so it's easy for me to get. ..Todd

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