EP-2750 impressions

[MPW]

I would be interested in hearing impressions of the Environmental Potentials EP-2750 ground filter from any who have experience with it. I am using a single dedicated 20 amp/10 gauge circuit and an AQ Niagara 5000 currently. The EP-2750 looks interesting and I believe a number of Sharks use it. Would love to know what they experienced. Thanks!

[jadedavid]

I had one installed last year by an electrician.
In my system I did not notice any difference.
But I guess I feel better having it in the system.
I would think that your Niagara would be more than satisfactory.

[SCAudiophile]

I have an EP-2050 on the main house panel and an EP-2750 on my dedicated circuit. When I put them in and also put in dual ground rods, the difference in noise floor was substantial as I recall (a few years ago...)

[Speedskater]

It's the exact opposite of what you want!
You need a low impedance path at all frequencies.
A series filter is a high impedance path at the filtered frequencies.

[SCAudiophile]

It's the exact opposite of what you want!
You need a low impedance path at all frequencies.
A series filter is a high impedance path at the filtered frequencies.

Having owned both the EP-2050 and EP-2750 from EP for 5 years, I've experienced nothing but improvements in noise floor, etc..with these
used on a properly grounded home (double ground rods, CADWELD bonding, solid core ground leads, large gauge wire, low impedance/very
low resistance path to ground).

Where did you find anything that allows you to conclude that the EP-2750 is a high impedance device?

[Speedskater]

Having owned both the EP-2050 and EP-2750 from EP for 5 years, I've experienced nothing but improvements in noise floor, etc..with these
used on a properly grounded home (double ground rods, CADWELD bonding, solid core ground leads, large gauge wire, low impedance/very
low resistance path to ground).
Where did you find anything that allows you to conclude that the EP-2750 is a high impedance device?

It's just an engineering fact. That's how a series filter works.

[SCAudiophile]

It's just an engineering fact. That's how a series filter works.

According to EP's technical support via phone this is not a high impedance device; I'm no electrician so I've asked the manufacturer for details.

All I know is the sonic benefit my system has accrued in using it.

[SCAudiophile]

It's just an engineering fact. That's how a series filter works.

I had a great conversation with Naveen, one of their lead engineers this afternoon. He provided the following explanation after our call.

Please note that the EP-2750s and 2775s (for much bigger applications than a single audio circuit) are ZERO IMPEDANCE devices at 60Hz for the US which is AFAIK what we want.

"EP ground filter comes in two sizes 2775 and 2750. It can be installed at the service entrance and also at the sub-panels to eliminate the high-frequency noise through the ground. It is always connected in series. The ground filter is a tuned low pass filter that attenuates high-frequency noise on the ground wire. The EP2750/2775 is a ground filter with zero impedance for fundamental frequency 60Hz. Its impedance raises and it acts like a speed bump for the transients at high-frequency range.
Typical applications of ground filter include protection from lightning EMI entering the facility and removing ground loop currents. It can be installed at the service entrance to protect the facility from lightning EMI entering the facility. It can also be installed at the load center to remove high-frequency noise generated on the ground wire of the load."

He also sent a product data cut-sheet, etc...if anyone has any questions I'd suggest communicating directly with the manufacturer to get their opinion on this first hand.

[Speedskater]

I had a great conversation with Naveen, one of their lead engineers this afternoon. He provided the following explanation after our call.

Please note that the EP-2750s and 2775s (for much bigger applications than a single audio circuit) are ZERO IMPEDANCE devices at 60Hz for the US which is AFAIK what we want.

"EP ground filter comes in two sizes 2775 and 2750. It can be installed at the service entrance and also at the sub-panels to eliminate the high-frequency noise through the ground. It is always connected in series. The ground filter is a tuned low pass filter that attenuates high-frequency noise on the ground wire. The EP2750/2775 is a ground filter with zero impedance for fundamental frequency 60Hz. Its impedance raises and it acts like a speed bump for the transients at high-frequency range.
Typical applications of ground filter include protection from lightning EMI entering the facility and removing ground loop currents. It can be installed at the service entrance to protect the facility from lightning EMI entering the facility. It can also be installed at the load center to remove high-frequency noise generated on the ground wire of the load."

He also sent a product data cut-sheet, etc...if anyone has any questions I'd suggest communicating directly with the manufacturer to get their opinion on this first hand.

Nope, you want as low an impedance at all frequencies as possible!

I was just reading a small part of the 500 page Motorola paper on cell-phone tower and building AC power & grounding. They wrote about how the wire from the service entrance point to the ground rod system should be a straight as practicable. With only mild curves, because bends act as an inductor and increase impedance at higher frequencies. The problems are not at 50/60Hz, but at higher noise & interference frequencies.

The Safety Ground system and the ground rod system are there for safety. Devices like these decrease the safety of the systems a lot!
Ask them if each unit has a 'UL' sticker?

While they may say that it passed this test or that test, the thing that matters is that there is a sticker on the unit that you purchase.

[Speedskater]

double post

[SCAudiophile]

Nope, you want as low an impedance at all frequencies as possible!

I was just reading a small part of the 500 page Motorola paper on cell-phone tower and building AC power & grounding. They wrote about how the wire from the service entrance point to the ground rod system should be a straight as practicable. With only mild curves, because bends act as an inductor and increase impedance at higher frequencies. The problems are not at 50/60Hz, but at higher noise & interference frequencies.

The Safety Ground system and the ground rod system are there for safety. Devices like these decrease the safety of the systems a lot!
Ask them if each unit has a 'UL' sticker?

While they may say that it passed this test or that test, the thing that matters is that there is a sticker on the unit that you purchase.

There was on the units I purchased and put in a few years ago or my Electrician would have refused the job. He also called the company and discussed
the installation method, nature of the devices, etc....before he did the install.