Donner Special-Ⅰ Professional High-Performance Passive DI-Box Review

In the following article, we’re taking a closer look at the Donner Special-I Passive DI Box, a budget-friendly passive DI option from Donner Music.

Live and Let DI

If you are looking for a reliable DI, guitarists as a whole are fairly spoilt for choice nowadays.

Products from Sansamp, Radial, and Fishman are highly regarded by professionals and bedroom guitarists alike and include a lot of additional features such as switchable attenuators (to eliminate excess gain from high-gain sources e.g. stereo systems), EQ, and polarity switching for eliminating feedback.

But with prices from anywhere up to $500 and beyond, are not ideal for those on a budget. Not to mention, many of the additional features listed above, while nice to have, are not strictly necessary for those simply looking to provide a balanced signal or split their signal when playing live or recording.

Many musicians turn to brands such as Behringer for this very reason e.g. They make affordable products, without some of the “nice to have” features, but tend to lack the build quality of the more established brands.

Donner, an innovative company producing everything from carbon fiber “smart” guitars to headless travel guitars, while tackling much the same market, in my experience tends to place more of a focus on build quality than many of their peers such as Behringer.

This is evidenced by their ever-expanding range of mini guitar effects pedals that have been receiving positive reviews, as seen here, and here.

The Special-Ⅰ Professional High-Performance Passive DI-Box is no exception, the clean minimal design, and sturdy all-metal construction belie its sub $40 price, giving the impression of a far more expensive unit.

Donner Music has offered readers of 15% off the RRP of all Donner products if purchasing through this link and using the code: CFAG
*This discount applies to all products on the website and doesn’t have an expiration date, so you can use the code at any time.

What is a DI (Direct Injection) Box?

For those unaware of exactly what a DI box does, they were originally designed to serve two purposes:

  1. Reducing Impedance
    A passive guitar pickup is high-impedance (Hi-Z). However, professional audio equipment e.g. mixing desks and PA’s, are typically low impedance (Low-Z). It’s important both the guitar and equipment being connected to are of the same impedance (level of resistance to the flow of current). Otherwise, the current flow between the two is inefficient and has the potential to cause a range of audible problems.
  2. Balancing an Unbalanced Signal
    A balanced signal is far less susceptible to interference, particularly over longer distances e.g. up to 100ft. A DI box usually takes an unbalanced (¼”) instrument cable and allows you to output an XLR cable which is capable of transferring a balanced signal over long distances (ideal for live performance).

While it’s beyond the scope of this particular article to go into more detail about what a DI box does and how they work, I have written a more in-depth explanation here, but in simple terms, if you play live or record acoustic guitar or bass a DI is something you might want to consider owning.

The Donner Special Passive DI Box

DOnner DI Box Instructions

The Donner Special-I Passive DI box comes neatly packaged and includes illustrated instructions for guitar, bass, and keyboards.


The unit includes a thru/bypass option for splitting your guitar signal.

Most DI’s offer Thru/Bypass, which essentially means you can split the signal coming from your guitar. e.g. You may want to run a 1/4″ cable to a fold-back monitor or amplifier (also Hi-Z), but also send a dry signal to a recording console or mixing desk.


The unit also contains a ground lift switch for eliminating hum caused by ground loops e.g. interference caused by connecting two pieces of equipment to a common ground.

It also features a sponge pad on the bottom of the unit for extra stability.

Ground lift switch, XLR out


  • Frequency response: 20 Hz to 20 kHz
  • THD+N (distortion): 0.003% @ 1 kHz,input level +4 dBu
  • Input: ¼” in TS (unbalanced)
  • Level Change (Input → Output): -20 dBu
  • Output: ¼” + Balanced XLR
  • Impedance ratio (Input → Output): 110 : 1
  • Dimensions (H x W x D): 4.17in x 2.51in x 1.79in (10.6cm x 6.4cm x 4.55cm)
  • Weight: 13.8oz (390g)

Testing the Donner Passive DI Box

I was looking for a quick and simple way to split my signal from my acoustic-electric guitar and also a quick and easy way to boost and clean up some of the hum when recording bass guitar.

The unit relies on the Donner LAB-S1 transformer for impedance matching, which probably means about as much to you as it does to me, as I’ve been unable to find out anything more about the transformer itself, but the proof is in the pudding as they say.

For testing, I plugged into the ¼” input and then ran a 1.4” directly into an amplifier while running the XLR out directly into my recording console.

And really, there’s not a lot to it from there. The unit does exactly what it is designed to do, without coloring the sound in any discernible way.

Next, I recorded three separate tracks of bass guitar.

I recorded the first straight in without any DI to use as a comparison. The second through the DI with ground lift switch off, which introduced a lot of hum, and lastly with ground lift switch on which provided a much cleaner bass tone than both the previous tracks.

Being a passive DI unit e.g. no additional voltage being added I wasn’t expecting track 3 to be significantly louder than track 1, but the track certainly had more presence.

What is a Passive DI?

You can read more here about the differences between passive and active DI here, but in simple terms, a passive DI doesn’t require an external power source. It’s best thought of as a transformer.

Whereas an active DI utilizes a power source, either through a 9V battery or 48V phantom power leveraged from the output source being plugged into.

In the majority of cases, you would use an active DI for equipment that produces a very low current e.g. a passive pickup on a guitar, as active DI’s usually include a preamp which will give the otherwise weak signal a boost.

However, keep in mind, that there are no hard and fast rules as acoustic-electric guitars often come equipped with a preamp, meaning a passive unit may, in some cases, be the better option. One of the real benefits of using a passive DI in this kind of scenario is it won’t introduce a greater capacity for noise.

Final Thoughts

Donner reached out and asked if I’d be interested in reviewing any of their products, i.e. they weren’t promoting anything in particular and were happy for me to select the product I felt would be of most interest to readers of this site. Having worked on another project with Donner in the past I was happy to agree as they have never given any direction or applied any pressure to view their products favorably. And, as evidenced in the review above, they also tend to make high-quality, affordable products.

So, if you are looking for an affordable DI unit the Donner Special-Ⅰ Professional High-Performance Passive DI-Box comes highly recommended. At a fraction of the price of most DI’s on the market you really can’t go wrong as it does exactly what it’s designed to do. 

More advanced musicians may want something more feature-laden but for the average beginner, bedroom guitarist or those new to recording the Donner Special-Ⅰ Professional High-Performance Passive will get the job done admirably and at a highly affordable price.

Donner Music has offered readers of 15% off the RRP of all Donner products if purchasing through this link and using the code: CFAG
*This discount applies to all products on the website and doesn’t have an expiration date, so you can use the code at any time.


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My name’s Marty. I’ve been into guitars, songwriting, and home recording for over 30 years. is my blog where I write about everything I have learned along the way.