The ART DTI Dual Transformer and Isolater is a high quality totally passive audio interface that uses a pair of high performance transformers to totally separate input and output signal grounds, thereby isolating two systems and reducing hum and ground-loop noise. The DTI’s audio transformers have an extremely flat and wide frequency response and can handle high signal levels while maintaining an isolated balanced output. This gives the DTI a very clean and neutral sound with a wide variety of signal sources. The transformers are wound for 1:1 unity gain and are designed to be used with impedances from 600 Ohms to 100k Ohms.
From the manufacturer
ART DTI Hum Eliminator Processor
The DTI (Dual Transformer/Isolater) is a high-quality, totally passive audio interface that uses a pair of high-performance transformers to totally separate input and output signal grounds, thereby isolating two systems and reducing hum and ground-loop noise. The DTI’s audio transformers have an extremely flat and wide frequency response and can handle high signal levels while maintaining an isolated balanced output. This gives the DTI a very clean and neutral sound with a wide variety of signal sources. The transformers are wound for 1:1 unity gain and are designed to be used with impedances from 600 ohms to 100k ohms.
What further sets the DTI apart from other lesser isolation boxes is its connection versatility. ART has provided XLR, 1/4 in. phone, and RCA-type phono connections on all inputs and outputs. This allows it to easily fit into virtually any audio system and be the clean patch point between all types of systems.
- Frequency Response: 10Hz –50kHz, +/-.5dB @ +4dBu
- THD: .01% Typical @ 1kHz, +18dBu, <.05% @ 100Hz, +24dBu
- Insertion Loss: .4dB @ 100k Ohm Load, 5.5dB @ 600 Ohm Load
- Input Connections: XLR female balanced, 1/4” TRS unbalanced, and RCA type phono jacks
- Output Connection: XLR male balanced, 1/4” TRS unbalanced, and RCA type phono jacks
- Power Requirements: Passive
- Dimensions: 1.75”H x 4.2”W x 3.5”D (44.5mm x 107mm x 89mm)
- Weight: .75 lbs. (.34kg)
Whether you need an interface between a computer based audio workstation and your monitor system, isolation on long cable runs in a fixed installation, isolation of a signal source from your recording equipment, or in many cases, just a safer connection between two audio systems, the DTI can accommodate.
The compact black anodized all aluminum case and it’s passive design allow the DTI to provide years of trouble free service in Live Sound, Permanent/Fixed Install, D.J., and virtually any PA application. It’s full feature set, rugged construction, and high-end specifications make the DTI the obvious choice.
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Allan H. –
Worked to eliminate high noise floor/static with my new speakers!I recently replaced older speakers that were no longer working properly with new ones.The new ones must have been much more sensitive to line noise as there was a very noticeable constant static noise.After installing this, the noise completely went away. Highly recommend if you have the same issue.
Mark King –
TRANSFORMER SAVIORI 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 1×4 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.
Steve Kennedy –
You cannot fix all audio issues with any single “magic” isolation box!I have a number of ART DTI boxes employed in a variety of situations and have found it to be effective for its’ stated design. I see a LOT of people who treat this product as a solution to EVERY problem involving hum and buzz. This product is NOT a solution for every form of noise issue.If a system has an induced hum or buzz NOT related to a common ground problem between the two systems being isolated then the DTI will NOT solve that problem! You can try it at different points in the signal chain and MAY find a spot that kills your noise.However, if the buzz exists prior to the point in the signal chain where the DTI is connected it will probably not effect the noise because the problem already exists upstream in the signal chain. The same goes for a buzz or hum occurring due to an issue AFTER the point where you insert the DTI. Sometimes you must try the DTI at several points in the signal chain until you can interrupt the ground loop where the noise is generated. The DTI is not a noise cancellation system, it is a signal isolation system… a BIG difference.Also, a system adjacent to a large AC transformer field can have induced hum or buzz and an isolation transformer will not solve this. Moving the equipment out of the hum field of the AC transformer would be the only way to solve this issue. Also, an amplifier with bad filter capacitors that cause a hum in the signal can only be fixed by replacing the bad capacitors. You can also try a steep parametric filter to cut-off the frequencies involved to mask them if you cannot identify and solve the actual CAUSE of the noise.
Chris C –
Lots of features, poor performanceI purchased this item to try to eliminate hum from my two subwoofers in a dedicated home theater. Each subwoofer and my audio rack are on their own dedicated circuits. My first attempt was using XLR with an ethercon breakout box and Cat8 STP cabling. This resulted in a loud hum and hiss from the subs which is where this device came in. There was only a slight reduction in hum with the XLR connections and it was still very audible even at the opposite end of the room, 30+ feet away. I switched to unbalanced RCA connections instead with this device and found the hum was reduced much more. There was still some faint hum that came and went and hiss audible in quiet passages.Throughout a couple of weeks of usage I noticed some occasional distortion in movies though. I played pink noise through the subs and there were cracking sounds, as if the drivers were damaged. I noticed more of the same with sweeps below 30hz. These noises went away when I removed this unit and used cheater plugs on the subs.I replaced this unit with two Blue Jeans isolation transformers. They had none of the distortion that I experienced with this unit and had a much lower noise floor.4/3/2022 Update: I switched surround processors in my home theater again and ran into more noise issues with my subwoofers that were not being resolved with isolation transformers over RCA cables. I decided to try running XLR cables straight to my subwoofers, which would require new in-wall cable runs. The switch to straight XLR runs got rid of ground loop between my subwoofers and the rack but I was left with a constant 60hz buzz whenever my projector was powered on. I still had this device on hand so I gave it a try again with XLR this time… and it worked! No buzz with the projector powered up. I ran through all of the test tones I had used while troubleshooting RCA connections with this and did not notice any of the artifacts that I found with RCA. So XLR seems to work alright with this unit. I added one star for the success over XLR. I still wouldn’t suggest one of these for RCA usage.
Scott Bloomquist –
Very handyI’ve used this for years till it got misplace or stolen. Very very handy as a kind of a mismatched cable interconnect, especially RCA to XLR. I use it when someone is trying to hook up their antiquated equipment into my system. It gives me that versatility. It’s too expensive for a permanent hook up that way, you’d use for a temporary fix and buy the proper cables. Not sure if it helped in anyway with noise, my system is pretty clean but I’m thinking it probably had to especially going from unbalanced to balanced, RCA to XLR, that’s very often a noisy hookup.
WorksIt got rid of my noise ground loop. Its odd shape me it hard to hide in the back of my rack.
Poor common-mode rejection ratioThis product is well designed in terms of functionality.Excellent bandwidth and distortion performance at moderate signal levels.But the transformers used in this product have poor isolation, even at 60Hz.Beyond 60Hz common-mode rejection deteriorates further.This design cannot cope with equipment connected to multiple mains withouta 10K shunt resistor to pull “isolated” output ground to within a few hundred millivoltsof amplifier input ground. But there is no external ground connector for output side.So a kludge is required. Jensen transformer based products have superior isolation,but then they cost 4x, which is why I didn’t give this product one star.
It worksI 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.
Amazon Customer –
Not For Electrical Ground Problems Main House WiringWorks but will not eliminate ground problem caused by multiple circuits in electric panel.Good to separate two amps on same power line.
Michael A. –
Does the trick!Completely eliminated a pretty nasty ground loop hum in a home theater RCA cable zoned audio hookup. Although I didn’t put the audio quality of the DTI through a proper stress test, it’s apparently a great middle ground between low-end products and the high-end transformers on the market. I liked the looks of the box’s transfer function specs!The only con I can think of, is that it doesn’t come with any kind of wall-friendly mount (like screw head insets) on the casing. Two zip tie mounts, and a single zip tie worked perfectly for the case shape. Since most audio pros probably don’t consider this in a mobile/gig setup, it still gets 5 stars for being such a quality product.