Isolation transformers....

XLR2XLR · 13th January 2008

I have a set of stereo transformers that I put between my and 3rd party
sound setups (when I am taking a stereo feed)

Are there any in depth articles about why this is a safer practice.

Thanks

Jim vanBergen · 13th January 2008

http://www.jensen-transformers.com/apps_wp.html

Bill Whitlock from Jensen Transormers is considered the foremost authority. Read & enjoy!

JvB

**Remoteness** · 13th January 2008

The short answer is...

Isolation transformers decouple the two different system chassis grounds from each other preventing mechanical ground loops.

XLR2XLR · 14th January 2008

Many thanks guys, as the grounds are isolated from each other does this
give additional protection if either I or the 3rd party has a fault condition
i.e. (mains live touching mixer chassis etc).

You see I remember somewhere that the BBC never connect to anything without
DI's or isolation transformers, I guess this is a pure safety issue (plus avoiding ground loops)

On thing for sure, I did not take into account the costs of buying a rig including all
the transformers (mics and lines !!!!) but on the other hand I want to be safe, I want to do this
properly.

Thanks

Jim vanBergen · 14th January 2008

If you're taking a stereo feed, a pair or two of decent inline transformers is pretty inexpensive. I use the Masque Sound Super IL-T (a Jensen transformer) for $69 each, which is really nice. I also have a couple of Jensen "project boxes" that are great, but bulkier.

When it comes to splitting microphones, it makes sense to invest in the best trannies you can buy. Steve Remote has a dedicated thread for this I believe, and it's an excellent read.

JvB

t_chance · 14th January 2008

I saw a good reason for isolation. At a venue I was at (not working), someone plugged a video camera into the board and it fried an output channel on the Crest. Literally smoked it, by pushing phantom into the board. They were so upset when they couldn't get the feed for their camera for their friends set off the board. The show went on with a little rerouting, but needless to say, I will give out only iso feeds from now on.

I just noticed you passed twoK JvB. Thanks much for all your expertise.

LX3 · 14th January 2008

Good point, well worth watching out for. Phantom power can instantly destroy the output stage of some mixers or other line-level devices...

I know, because I did this to a bit of my own gear once!

The phantom thing is usually only a problem on equipment like cameras where line in and mic in share the same connector.

But watch out for MOTU 896s too. It can throw 48v down a line input.

LX3 · 14th January 2008

Quote:

Originally Posted by t_chance

They were so upset when they couldn't get the feed for their camera for their friends set off the board.

Not as upset as the owner of the desk, I suspect!

13th January 2008	#1
XLR2XLR Gear addict Joined: Jan 2006 Posts: 317 Thread Starter	Isolation transformers.... I have a set of stereo transformers that I put between my and 3rd party sound setups (when I am taking a stereo feed) Are there any in depth articles about why this is a safer practice. Thanks

13th January 2008	#2
Jim vanBergen Lives for gear Joined: Apr 2005 Location: New York Friggin' City Posts: 2,562	Try this link: http://www.jensen-transformers.com/apps_wp.html Bill Whitlock from Jensen Transormers is considered the foremost authority. Read & enjoy! JvB

13th January 2008	#3
Remoteness Super Moderator Joined: Aug 2002 Location: NYC Posts: 7,405	The short answer is... Isolation transformers decouple the two different system chassis grounds from each other preventing mechanical ground loops. __________________ Steve Remote AuraSonicLtd.com the home of ASL Mobile & Location Production Remoteness on the Linkedin Network What about my Facebook Profile? Remoteness on Myspace

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14th January 2008	#4
XLR2XLR Gear addict Joined: Jan 2006 Posts: 317 Thread Starter	Many thanks guys, as the grounds are isolated from each other does this give additional protection if either I or the 3rd party has a fault condition i.e. (mains live touching mixer chassis etc). You see I remember somewhere that the BBC never connect to anything without DI's or isolation transformers, I guess this is a pure safety issue (plus avoiding ground loops) On thing for sure, I did not take into account the costs of buying a rig including all the transformers (mics and lines !!!!) but on the other hand I want to be safe, I want to do this properly. Thanks

14th January 2008	#6
t_chance Gear maniac Joined: Aug 2005 Location: St Paul MN Posts: 162	I saw a good reason for isolation. At a venue I was at (not working), someone plugged a video camera into the board and it fried an output channel on the Crest. Literally smoked it, by pushing phantom into the board. They were so upset when they couldn't get the feed for their camera for their friends set off the board. The show went on with a little rerouting, but needless to say, I will give out only iso feeds from now on. I just noticed you passed twoK JvB. Thanks much for all your expertise.

14th January 2008	#7
LX3 Lives for gear Joined: Aug 2005 Location: London, UK Posts: 1,033	Good point, well worth watching out for. Phantom power can instantly destroy the output stage of some mixers or other line-level devices... I know, because I did this to a bit of my own gear once! The phantom thing is usually only a problem on equipment like cameras where line in and mic in share the same connector. But watch out for MOTU 896s too. It can throw 48v down a line input.