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[Geoff Doane]

How much will the Whirlwind version cost?

Whirlwind already has a version, except they did it right:

http://whirlwindusa.com/catalog/black-boxes-effects-and-dis/transformers-isolation-devices/iso-2-dual-line-level-isolator-and-balancer

Yeah, it's more than $50, but at least you're not messing with the SAFETY ground of your equipment.  If you want to roll your own, decent 1:1 transformers can be found pretty cheap, if you know where to look.

GTD

(Disclaimer: I'm a Whirlwind dealer, and have bought and used the ISO2, as well as rolling my own ISO transformer boxes.  I also seem to be able to get away with plugging my modern and not-so-modern digital consoles in to wall outlets that are handy to FOH, and haven't had any hum problems yet without resorting to any special tricks.  Maybe that's because the consoles, and new power amps at the other end of the snake, have properly addressed the pin 1 problem.)

[Al Keltz]

How much will the Whirlwind version cost?

No plans to make one at this time.

- Al

[Jerome Malsack]

The problem of ground loop with a shielded RJ45 is still present.  The big reason is because the RJ45 passes data, The data is then converted to analog audio.  How the Audio is connecting and providing to the amp is where the loss of the ground connection is being handled.  The box doing the D/A is in the same power as the amps and I would believe that the amps are already set with ground lift.  Preventing a ground loop between the amps them selves.  This is why your not hearing the hum.  If you add two amps with grounds connected and the head of the Snake Stage box with the D/A.  Add the mixer at the other end on another outlet,  you will still see the ground loop hum.  If you change to unshielded RJ45 the hum might still be there.  Remove the amp grounds on pin 1 and the hum goes away.     

[Bob Leonard]

No plans to make one at this time.

- Al

If you make them I will buy them.

[Bob Leonard]

Whirlwind already has a version, except they did it right:

http://whirlwindusa.com/catalog/black-boxes-effects-and-dis/transformers-isolation-devices/iso-2-dual-line-level-isolator-and-balancer

Yeah, it's more than $50, but at least you're not messing with the SAFETY ground of your equipment.  If you want to roll your own, decent 1:1 transformers can be found pretty cheap, if you know where to look.

GTD

(Disclaimer: I'm a Whirlwind dealer, and have bought and used the ISO2, as well as rolling my own ISO transformer boxes.  I also seem to be able to get away with plugging my modern and not-so-modern digital consoles in to wall outlets that are handy to FOH, and haven't had any hum problems yet without resorting to any special tricks.  Maybe that's because the consoles, and new power amps at the other end of the snake, have properly addressed the pin 1 problem.)

Not the same product, not even close. The problem being discussed is AC hum, 60 cycle, generated by the 120v power source as a result of poor or incorrect grounding. In the 60's we fought with this problem ALL THE TIME because most outlets were not grounded at all. Today a majority of this hum is due to the receptacle being wired backward regardless of having a ground. What the Hum X does is place a pair of back to back diodes in line with the ground eliminating the hum in most cases. In the 60's if you had this issue you flipped the AC cord. Today the HumX does this for you but maintains the ground. This has nothing to do with pin 1 or isolation transformers used prior to the input for the channel.

[John Rutirasiri]

I have my mixer and FOH rack on an online UPS. Never had a hum problem, and never lost audio because someone kicked the cord.

You can also try an isolation transformer (good ones are toroids or iron core with Faraday shield).  Get medical-grade ones -- pretty cheap on eBay. 

For what a decent wattage isolation transformer weighs though, you might as well get a UPS.

[Steve M Smith]

If by isolation transformer, you mean a power transformer rather than one for audio, this will make no difference as it's a ground loop problem.


Steve.

[Geoff Doane]

Not the same product, not even close. <snip>

No, it's not the same, and that was my point.  The Whirlwind ISO doesn't mess with the safety grounds of the equipment involved.  Instead, it allows you to lift the audio ground that would otherwise cause the ground loop and resulting hum.  It is another way of accomplishing the same end (and IMHO a much better solution).

The HUM-X  has the problem of having soldered connections in the safety ground path.  I believe that is frowned upon by the safety listing agencies.  In theory, it's possible for a very high fault current to flow, heat up the solder to the point it melts and explodes, leaving you with no ground .  I'm not so concerned about the integrity of the diodes themelves.  In over 30 years of repairing electronic devices, (including 6 years with high power broadcast treansmitters) I can't think of any diodes that failed open.  They were always a dead short in both directions, and often showed no outward signs of damage.

GTD

[Steve M Smith]

In theory, it's possible for a very high fault current to flow, heat up the solder to the point it melts and explodes, leaving you with no ground.

An RCD (or GFCI) should cut the power long before that happens.

I can't think of any diodes that failed open.  They were always a dead short in both directions

Semi conductors are always trying to upgrade themselves to full conductors!


Steve.

[David Sturzenbecher]

No, it's not the same, and that was my point.  The Whirlwind ISO doesn't mess with the safety grounds of the equipment involved.  Instead, it allows you to lift the audio ground that would otherwise cause the ground loop and resulting hum.  It is another way of accomplishing the same end (and IMHO a much better solution).

The HUM-X  has the problem of having soldered connections in the safety ground path.  I believe that is frowned upon by the safety listing agencies.  In theory, it's possible for a very high fault current to flow, heat up the solder to the point it melts and explodes, leaving you with no ground .  I'm not so concerned about the integrity of the diodes themelves.  In over 30 years of repairing electronic devices, (including 6 years with high power broadcast treansmitters) I can't think of any diodes that failed open.  They were always a dead short in both directions, and often showed no outward signs of damage.

GTD

I believe UL doesn't allow any interruption (not just the fact that there is solder) of the safety ground path for device certification. Logically though, the diode failing in a dead short situation would be the best possible failure method.


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