Serene Innovations Universal Handset and Headset Amplifier

I tried a few other amplifiers that I had used at another job and those did not work on the new work phone so I tried this and it works very well. I can actually hear all the callers which is very important for my job! The sounds is very clear and easy to change from handset to headset you do have to push down the headset botton when you want to hear from the headset I was used to this with my old ampliefiers so once you get used to switching back and forth you are good to go. The volume gets pretty loud I use it at about 40 -50 % capacity if you will and this is perfect with a normal phone I was maxing the phone volume out and still not hearing properly so this does boost the volume as stated. Please note you have to buy the 50 ( the more expensive one) if you want it to work with a headset but the cost is not bad considering.

It would only work with my headset if plugged into telephone jack on Amplifier and even then with occasional screeching which would stop if volume reduced so low I lost enough amplification that I couldn't hear other party. Telephone handset plugged into headset jack at same time would not work at all with or without Headset button activated. Only Compatibility setting no. 1 worked. No 5 had terrible screeching at any volume setting. I don't think this unit was designed very well. Will try something else.

This amp is amazing! Easy to hook up with in seconds and has tons of power for volume and tone. Buy the Serene Innovations UA-50 (IMHO - The Cadillac of amplifiers) and you will never have another problem hearing on the phone no matter what level of hearing loss. I went to work and installed the optional 9 volt (also comes with power cord) and installed it to my office phone all in about 40 seconds. I first adjusted the phone "compatibility" switch on the right side of the unit. Second, I adjust the "tone". For me, I have high frequency / high pitch hearing loss. I click the "tone" switch up two notches and all my phone calls are crystal clear. Lastly, I adjusted the volume knob to the first white block on the unit - simple as that. There is a "boost" button but with the amount of "horsepower" even before engaging this feature, I can say with certainty I will never use it. There is also a "headphone" button next to the "boost" button so you can utilize headphones. The reason for me using the optional 9 volt is so I can move the device to another office phone in a jiffy. Definitely a five star product and highly recommend to anyone with hearing loss. I have no regrets for spending this type of money for a phone amplifier.

This so far is the best telephone amplifier that I've used. It has very good sound quality. Some of the others I tried had buzzing when you turned them .

I have an unusual situation where my office phone is connected to an audio conferencing system through the headset jack. Everything works great, except that the sound through the speakers is a bit too soft, so I hoped an amplifier would help. While this unit helped somewhat, it also introduced a lot of buzz and hum, and I found it didn't work that well with the Cisco VoIP phones in my office, even when used as a conventional headset amplifier.Seems okay from a construction quality perspective and it was easy to setup, but I imagine your results will vary depending on how you intend to use it and the type of phone you connect it to.