Avenson Audio IsoDI direct-inject box
Before anyone wonders if I am going to get this, no…I am not. I have a great stereo DI box and it is a fantastic piece of equipment. But I must say that this one by Avenson Audio caught my eye when I was doing a New Year’s gig a couple of days back. Apparently, the supplied DI boxes were giving some issues and so the audio engineers came up with this DI box and replaced the so-called faulty DI boxes. I must admit that I was fascinated by their size. Here is what Avenson Audio has to say about them:
The IsoDI adds two optional isolation stages.
The main signal path is still a clean, wide bandwidth transformer-less FET amplifier, but the power is generated with an isolated DC to DC converter so that you can have true ground isolation and still run the IsoDI on phantom power.
The IsoOut jack can be a buffered, transformer isolated output to feed amplifiers or other inputs that can compromise the performance of the main signal path if connected in parallel. Now there is a way to get a clean DI signal even when there is bad stage power that causes the amp to buzz from light dimmer hash!
The switchable IsoOut / Parallel jack give you the flexibility to configure the jack as a summed input, a parallel connected output, or a transformer isolated output.
There is the caveat all…no transformers in this device at all. To me, transformers are vital in DI boxes…but then again, I am from the old-school of thought.
———- EDITOR’s NOTE ———-
I got a reply to this post (please see the comment). If you cannot see it, no worries. I will post it out in full below. Thanks to David from Avenson who wrote this
Thanks for the write-up about our IsoDI. In full disclosure, I work for Brad here at Avenson Audio doing all the assembly, testing, repair and some design work on our products. I came across your post while searching for new user reviews on our IsoDI for our new website. Just wanted to provide a correction though, the IsoDI does in fact have a transformer inside. The real beauty of the IsoDI (and probably precisely why your audio engineer friends at the NYE gig used them for solving their issues) is the Parallel/IsoOut push-button switchable circuitry. Essentially the IsoDI can either be a clean and uncolored, transformerless Active DI for getting the truest flat frequency response for recording studio use or live situations with no noise problems, or at the push of that Parallel/IsoOut button, you can switch in the transformer isolation circuitry which isolates the DI out signal from all the noise and ground hum issues you may have on the stage power and in your amp. For solving even more hum problems from Ground Loops, there is a Ground Lift switch which actually provides a true ground lift (unlike most DI boxes), by using a DC-DC converter in the power supply to isolate the Audio circuit ground in the IsoDI from the incoming 48V ground via pin 1 of the XLR. To the best of our knowledge, no other DI on the market has this DC-DC converter true ground lift in their circuit, which is why ours performs so much better than others in solving noise and ground hum issues. Thanks again for the write-up, and if you ever run into more of these noise issues at a gig I hope you’ll reconsider buying one of our IsoDIs for yourself. Cheers!
In addition to that, he also gave a link to a technical explanation of the DI boxes. Thanks David. Appreciate it!