ARTART DTI Dual Transformer Isolator Hum Eliminator

I work in a small studio that creates music content and broadcasts live video shows over the internet. Sometimes we simulcast to three different mediums (two audio-video encoders and one audio-only encoder). The output of our mixer also feeds several headphone amps in the studio. All-in-all it's a big recipe for ground-loop hum, the splits to the video encoders are the biggest culprits, suffice to say it's an engineering nightmare.Our hum and noise problem got very big when we added video to our broadcasts and it seemed like there was no way to get rid of it. We already have a 3-way splitter transformer on the output of our console and there was no way to add another one without degrading the sound. I tried a 1x4 distribution amp but it did not have the isolation to break the ground-loop hum so that was not an improvement, indeed, it was actually a step backwards in some ways.We had a big show coming up and I really wanted to fix the audio but I did not have time to build another transformer isolation box for the inputs to the video encoder so I turned to my friends at Amazon for a solution.To be honest, I did not think this box could possibly work. I normally pay more for one raw audio transformer than this completely assembled two-channel unit. I ordered one and got it in two days as promised. Our studio mixer had one set of unused RCA outputs for hooking up to a stereo recorder. I used these to feed a signal to this little ART box, then I used the RCA outputs from the ART to feed into our video encoder. PROBLEM FIXED.I was stunned at the tone quality the ART produced. We are doing music, it's a full range rock band, deep punchy kick drums, mondo bass guitar, screaming guitar leads, sweet cymbals and amazing harmony on the vocals. We record the show right out of the encoder so we have a reference file of what was broadcast. After the show I listened to the recording and it was very impressive, not only was the hum gone but the whole signal seemed cleaner and better in ways that it should not have been. I don't know whether the HUM had been causing high intermodulation distortion or what, but what I do know is our music that is going out on the internet is sounding like we want it to sound, big, full, rich and hum-free.The variety of input and output connectors on this box allows it to be connected in lots of different ways. We're in the process of moving to a larger studio and I will be adding a few more of these to solve other problems in our personal monitoring system that the performers listen through.I did some tests in my lab to determine the quality of the transformers inside this ART box. To be honest, it does change the frequency response slightly but not in a hugely adverse manner. Bass frequencies below 50 hz are a little more distorted on very loud signals, that is what I could measure in the lab. In the real world nobody is going to hear the slightly degraded sound and everybody is going to appreciate the removal of ground-loop hum.If your hum is caused by some other source this box is not going to get rid of it, it's not a hum canceling or hum removal sort of thing. It removes hum by breaking ground loops, plain and simple. It does that well as far as I can tell and at this price it is a real winner.

This product solved my ground hum issues. It does introduce a very slight degradation in audio quality as well as a slight loss in volume. I am very picky with my audio and have professional monitors and I can notice a slight loss of quality, but when you have ground problems.. this is the best solution I have found aside from fixing the actual wiring issues. I think that overall this is a good value product and works when you have no other choice. It will work best in applications where mastering and absolute sound quality are not needed. It works significantly better than the cheap rca ground hum eliminators

Unfortunately did not work for me. Actually made matters worse. Returned and am looking for an alternate solution.

This isolation transformer works pretty well, but there is some frequency loss. For example, a signal with rich lows will sound more "tinny" after passing through the DTI, but this can probably be compensated for by changing the EQ settings.

Most audio gear uses a standard 2 prong plug, so ground loops aren't much of an issue. When adding an equalizer and a computer to my theater setup, both having a 3 prong plug, I got nasty buzzing and crackling. I grounded the two components to rack which helped a lot, but still left a small, but audible buzz. The DTI did a stellar job cleaning up that final bit of interference, and didn't add anything into the signal chain. Quite a fantastic product.

I use this in tandem with a room measuring program. The program supplies the sine wave output through the front faceplate, headphone out on the PC based computer system. I connect this appliance to the AVR front analogue in via a short stereo set of RCA terminated interconnects. The ground loop hummmmm, was immediately corrected for.When running sound measurement sine wave sweeps to measure the room's acoustics, we had a ground loop hum being added to the signal path that could be heard in either the center channel speaker or the main L/R speakers. When this unit was added, the hum was immediately corrected for.For those who want measurements:I put a digital mult-meter on the headphone output and took a reading of the left RCA connector. Without the isolator, I get a reading of 13.1mV. When the isolator is attached, measuring the left output side, I get a measured 00.1mV. I measured the right RCA connector. Without the isolator attached, there was a reading of 12.6mV. With the isolator attached, measuring the right output side, I get a measurement of 00.1mV.The above are the measured facts.Overall, this unit is well constructed with a large compliment of input/output connection choices:Female, 1/4" TRS: Tip-Ring-Sleeve connectorsFemale, XLR connectorsFemale, RCA connectorsEmpirical measurements show, this unit works.Hope the above helps in your buying decision.