This forum includes tips for maintaining the best audio quality possible with the Ooma System. If your Ooma system is having issues with dropped calls, static audio or echo, look here for assistance.
#95560 by thunderbird
Fri May 04, 2012 9:27 am
FRET_BUZZ wrote:I had the same problem. I am using the Telo with a wireless adapter. Connected to the Telo is a phone with a Plantronics headset. I replaced both the phone (AT&T and Panasonic) and the Plantronics headset (2 different headsets and S11s). All interconnect cables were replaced as well. The problem is isolated to the Telo. I am suspecting the power supply is under powered which increases power supply ripple to the Telo. I resolved most of the issue by turning off the status lighting.

If you think the Ooma Telo is defective, you should exchange it while it is still in the one year warranty period. You will have to contact Ooma (and at first jump through some hoops). Ooma will send you a replacement Ooma Telo shipping prepaid. They will also send along a prepaid shipping label to ship the defective Ooma Telo back. When it arrives it is already preprogrammed with your Ooma profile. All you have to do is plug it in.

Customer Support
Email: support@oomacare.com
Phone: 1-888-711-OOMA (6662)
Monday-Friday 7am-7pm PST
Saturday-Sunday 8am-5pm PST
#95561 by WayneDsr
Fri May 04, 2012 9:29 am
FRET_BUZZ wrote:I had the same problem. I am using the Telo with a wireless adapter. Connected to the Telo is a phone with a Plantronics headset. I replaced both the phone (AT&T and Panasonic) and the Plantronics headset (2 different headsets and S11s). All interconnect cables were replaced as well. The problem is isolated to the Telo. I am suspecting the power supply is under powered which increases power supply ripple to the Telo. I resolved most of the issue by turning off the status lighting.

OR possibly a bad power supply.

Wayne
#95806 by jdurand
Sat May 12, 2012 9:18 pm
I recently installed Ooma Telo as our home phone line. We have a home office so there's a business land line and I have both going to an AT&T 993 dual line telephone as well as other individual phones on the business line.

If I pick up an individual business phone, audio is fine.

If I pick up the dual line phone and select either the Ooma line or the business line, I get a hum.

If I unplug the Ooma line from the dual phone then the business line is quiet.

If I unplug the business line, the Ooma line is quiet.

Here's the important one...

If I unplug the Ooma AC adapter while leaving the network plugged in, the business line is quiet.

Unplugging the AC adapter from the AT&T phone makes no difference (it has a battery to keep it running without the adapter).

Edit to add: The AT&T with two land lines plugged in (my old home line and the business line) is dead quiet.

So, it seems there's AC leakage in the Ooma Telo. As long as your phones don't have a connection to the AC line or ground, they'll be quiet. If they do (cordless, feature phone like the AT&T, etc.), then you may have hum.

My background: Former chief engineer at a company that built telephone central office test equipment and designer of some of the very first computer sound boards.
#95807 by jdurand
Sat May 12, 2012 9:38 pm
I just found a fix for all but a very very slight hum, all the buzz is gone...

Get a USB cable and plug it into the USB port on the back. Connect the metal shield (outside silver part) of the plug on the other end of the cable to ground. You could use a clip lead to hook it to a metal computer case (if it's plugged in), or the mounting screw in the center of a grounded power outlet.

So, the problem is the AC adapter has way too much AC leakage. I didn't measure it but will be digging through my spare parts bin for a better one.
#95808 by thunderbird
Sun May 13, 2012 2:51 am
jdurand wrote:I just found a fix for all but a very very slight hum, all the buzz is gone...

Get a USB cable and plug it into the USB port on the back. Connect the metal shield (outside silver part) of the plug on the other end of the cable to ground. You could use a clip lead to hook it to a metal computer case (if it's plugged in), or the mounting screw in the center of a grounded power outlet.

So, the problem is the AC adapter has way too much AC leakage. I didn't measure it but will be digging through my spare parts bin for a better one.

Let the forum know how you come out.
Last edited by thunderbird on Sun May 13, 2012 10:13 am, edited 1 time in total.
#95814 by jdurand
Sun May 13, 2012 7:34 am
I tried an old Phihong brand adapter that had the right DC plug on it, same hum.

I plugged the Ooma adapter into an isolation transformer (this passes the AC power with no metallic connection between the power company and the outlet on it), hum is gone. Actually, with the ground clip on the USB cable I get a little hum but removing the clip gives me a quiet phone.

Getting a quiet, low cost SLIC* that's AC powered...and low cost... isn't easy. I'm guessing 100% of the testing done on the Ooma Tel was with a standard phone plugged into it and non-cheap isolated test equipment. I doubt it would have occurred to them to test it with multi-line and/or AC powered devices like cordless phones.

* SLIC = Subscriber Line Interface Circuit...it's the thingy** that powers the phone jack on the back of the Ooma including generating ringing.

** Thingy is a technical term for doohicky: http://www.urbandictionary.com/define.php?term=doohicky

:)

At least I didn't just say a SLIC provides BORSCHT. :)
#95822 by thunderbird
Sun May 13, 2012 10:24 am
jdurand wrote:I tried an old Phihong brand adapter that had the right DC plug on it, same hum.

I plugged the Ooma adapter into an isolation transformer (this passes the AC power with no metallic connection between the power company and the outlet on it), hum is gone. Actually, with the ground clip on the USB cable I get a little hum but removing the clip gives me a quiet phone.

Getting a quiet, low cost SLIC* that's AC powered...and low cost... isn't easy. I'm guessing 100% of the testing done on the Ooma Tel was with a standard phone plugged into it and non-cheap isolated test equipment. I doubt it would have occurred to them to test it with multi-line and/or AC powered devices like cordless phones.

* SLIC = Subscriber Line Interface Circuit...it's the thingy** that powers the phone jack on the back of the Ooma including generating ringing.

** Thingy is a technical term for doohicky: http://www.urbandictionary.com/define.php?term=doohicky

:)

At least I didn't just say a SLIC provides BORSCHT. :)

I would lean to maybe the Ooma Telo may have a malfunciton like curcuit the may not be grounded, or is grounded in the wrong place, causing a ground loop????

If your Ooma Telo is withing the one year warranty period, I'd think about contacting Ooma Customer Service and having your Ooma Telo replaced?
#95823 by jdurand
Sun May 13, 2012 10:36 am
thunderbird wrote:I would lean to maybe the Ooma Telo may have a malfunciton like curcuit the may not be grounded, or is grounded in the wrong place, causing a ground loop????

If your Ooma Telo is withing the one year warranty period, I'd think about contacting Ooma Customer Service and having your Ooma Telo replaced?


I really doubt it's a manufacturing defect, it's an artifact of what it is (a consumer product). The AT&T phone I have shouldn't have any way for one line to influence the other, but there's obviously some effect. Cordless phones should be fully isolated. Attention to details like that just aren't going to be found in a consumer product and are sometimes missed in "high end" industrial products.

For what it is and considering what passes for standards in programming for consumer products, I rank the Ooma Telo fairly highly and have recommended it to people already.
#95828 by Cyberchat
Sun May 13, 2012 6:24 pm
jdurand wrote:I just found a fix for all but a very very slight hum, all the buzz is gone...

Get a USB cable and plug it into the USB port on the back. Connect the metal shield (outside silver part) of the plug on the other end of the cable to ground. You could use a clip lead to hook it to a metal computer case (if it's plugged in), or the mounting screw in the center of a grounded power outlet.

So, the problem is the AC adapter has way too much AC leakage. I didn't measure it but will be digging through my spare parts bin for a better one.


Jdurand,

Telephone patch cords come in both four-wire and two-wire versions (just the center two conductors are present in the RJ-11 jack/plug for the two-wire version).

Did you try using just a two-wire telephone patch cord to connect your OOMA Telo device to your house wiring? Using a two wire version should eliminate any possible connection between the OOMA Telo and your business line service from your telephone vendor. In you don't have access to a two-wire telephone patch cord, you can use a "Telephone Line-1/Line-2 Splitter" to make sure there is no electrical connection between the OOMA Telo device and your business line service.

In the Telo, although it provides for only one physical telephone line connection (for Telephone Line-1) on the center two conductors/wires, the "Phone" jack does have all four conductors present. If the wires for the second line (the outside two conductors) are connected in some way within the Telo to its circuitry (possibly for future functionality) or are grounded you may have setup a ground-loop if you used a four-wire telephone patch cord to connect your Telo to your house wiring.
#95842 by jdurand
Mon May 14, 2012 1:17 pm
Cyberchat wrote:
Jdurand,

Telephone patch cords come in both four-wire and two-wire versions (just the center two conductors are present in the RJ-11 jack/plug for the two-wire version).

They also come in twisted pair and flat.
Did you try using just a two-wire telephone patch cord to connect your OOMA Telo device to your house wiring? Using a two wire version should eliminate any possible connection between the OOMA Telo and your business line service from your telephone vendor. In you don't have access to a two-wire telephone patch cord, you can use a "Telephone Line-1/Line-2 Splitter" to make sure there is no electrical connection between the OOMA Telo device and your business line service.

Two wire flat from Ooma to the AT&T phone Line 1 input (currently the only phone connected to Ooma). Twisted pair two wire to AT&T Line 2 input which also connects to other phones in the house (all twisted pair wire).

In the Telo, although it provides for only one physical telephone line connection (for Telephone Line-1) on the center two conductors/wires, the "Phone" jack does have all four conductors present. If the wires for the second line (the outside two conductors) are connected in some way within the Telo to its circuitry (possibly for future functionality) or are grounded you may have setup a ground-loop if you used a four-wire telephone patch cord to connect your Telo to your house wiring.

My Ooma Telo only the center two pins in the RJ-11 jack so other than cross talk if using a 4-wire flat cable it wouldn't matter if a two, four, or six wire cable was plugged in (yes, there ARE 6-wire/3-line or PBX cables...but rare).

I just ran a more permanent ground wire from the USB jack on the Ooma to a good Earth connection (center screw on the power outlet, I KNOW this particular one has a good ground) and now there's barely any noise at all. Actually better than some direct home line connections I've heard.

The Ooma Telo is working well and now is nice and quiet. All is good.

Who is online

Users browsing this forum: No registered users and 7 guests