Saturday, September 11, 2021


With so many companies making direct boxes I was surprised to see Warm Audio enter this space with not one but two new direct boxes. In this review we’ll be taking a look at the Warm Audio Active direct box.

FEATURE SET - Street price $199.00

This is a mono active direct box which can also be switched to be a passive direct box. A rotary attenuator is provided to contour source audio to the right level. A switch selects whether the rotary attenuator is in the signal path or not. The rotary attenuator has a nice smooth feel and the metal knob looks good too. The attenuation range of the knob is -3dB to -30dB.

Inside the WA-DI-A is a custom designed Cinemag USA audio transformer.

The body of the WA-DI-A is heavy gauge aluminum wrapped around an extruded aluminum inner chassis.  On the bottom surface is a nice thick rubber pad which protects what you set it on from scratches and spurious chassis ground connections. Overall the WA-DI-A feels very heavy duty.

A switch labeled AMP OUT or INSTRUMENT attenuates the input of the direct box to allow direct connection to the speaker output of an amplifier. There is no load or signal conditioning provided so it’s going to be a very bright sounding output from the D.I. XLR out. If you were feeding it from a tube amp you’d need to provide a load with the proper impedance. 

The WA-DI-A can be powered from two internal 9-volt batteries or 48-volt phantom power. If the box senses 48 volt phantom that is used and the batteries are not used. If you have neither of these power sources you can switch the DI to passive mode in which case no power is required. 

The chassis finish and labeling is easy to read in dim stage lighting.


I used the WA-DI-A with an American Standard Fender Stratocaster feeding a WA-73EQ preamp and recorded directly into my DAW. This setup delivered a pristine and beautiful guitar sound. I powered the D.I. with phantom 48-volt supplied by the WA-73EQ. Except for the hum from the guitar pickups the sound was crystal clean and free of noise. 

Next I used the WA-DI-A to connect my vintage DX-7 to the input of my Soundcraft studio mixer. The DX-7 sounded beautiful, crystal clear FM bell sounds without hum or distortion. This setup also gave a chance to compare the active vs passive modes available. The keyboard sounded great in both active and passive modes although I prefered the active setting, it had a nice sheen to the high frequencies without sounding bright or weird in any way. 

As a recording tool the WA-DI-A provides excellent sonics and overall performance. 


I like the heavy duty feel of the enclosure. The rubber pad on the bottom is a nice touch. 

The switches and knob feel high quality.

The XLR output connector worked with a variety of connectors ranging from Switchcraft to inexpensive Chinese. 

The sound quality is excellent, from electric guitar to electric 5-string bass to vintage keyboards, the WA-DI-A delivers premium professional performance. 


The “book style” enclosure does not extend out far enough to shield the switches and knob from physical contact. Warm Audio could have used switches with shorter baton handles so they would be protected by the enclosure. If I was using this for live applications I’d put it back in its box to keep it safe between gigs.

The corners of the book cover sides are sharp and pointy. You don’t want to stub your barefoot toe on the corner of one of these D.I. boxes laying on the floor. 

The “Manual” provided by Warm Audio says you can connect this inline with the speaker output of your guitar amp for recording. No “speaker signal conditioning” is provided so this would not be a good application in my opinion. Maybe if you recorded as suggested and then used an Impulse Response to condition the amp output to sound like it was connected to a speaker. Not my usual way of working but maybe it will work for you.

DANGER: Attenuator switches scare me, here’s why. Lets say you have this box in a setup with a lot of attenuation in use, what happens if someone accidentally flips the switch to disengage the attenuation? If you were using this for PA in a live venue you would be very sad because the sound coming from this D.I. box is going to get very loud, instantly. I would put the whole D.I. box in a small cardboard box and tape it shut so wandering hands can’t touch the “disengage” switch. 


The heavy duty construction and feel of this direct box are appealing. At $199 it’s not inexpensive, there are lots of very professional alternatives available at lower cost. 

The Countryman FET 85 is a classic active direct box you can literally drive the 2.5 ton band truck over and the box will be fine, it has a street price of $185 but does not have the rotary attenuator like the WA piece. 

Radial Engineering has active direct box models for $99-street and Klark Teknik has stereo models for $149. 

It’s a bold move for Warm Audio to move into making D.I. boxes with premium pricing. I hope it works for them, I like the company and their products. 

If you just want a great direct box without a bunch of research or comparison shopping the WA-DI-A offers an easy path to an excellent sounding direct box. 

Enjoy the journey, Good Music to You!


Frequency Response: 10Hz to 90kHz +/- .05dB

Linear Performance: +/- .05dB 20Hz to 20kHz

THD: .01% from 20 Hz to 50Hz, less than .003% from 50Hz to 20kHz

Input Impedance: 1 Meg Ohms

Balanced Output: 600 ohms, mic level

Pad: Variable from -3dB to -30dB

Power: 48V Phantom or two 9-volt batteries

This article is ©August 2021 by Mark King, it’s not ok to copy or quote without written permission. 

Good Music to You!