The Undertone Audio MPEQ-1 Equalizer packs a huge amount of Class A audio power into a single rack unit. Whether you are tracking or mixing, we are confident you will find the MPEQ-1 to be an indispensable tool in the music making process.
The development of the Undertone Audio MPEQ-1 began with the process of building a custom console. The Equalizer was the single most important element of the design. I needed an EQ that would do everything all of my other EQs did. It needed to have the musicality of a classic Neve or EMI but the flexibility of a GML or Orban. Larry Jasper and I worked for years refining the design that ended up in our consoles and is now available in the MPEQ-1. The equalizer in the Undertone Audio MPEQ-1 unit is identical to the Equalizer in the channel strips of the UTA consoles.
What’s so special about the EQ? It is the only Parametric Equalizer that utilizes Class A amplifiers for EVERY active gain stage in the EQ. Most “Class A” EQs will use a Class A gain stage only for the final summing stage. The UTA EQ uses Class A gain stages for all of the integrator stages, all buffering stages, summing stages… Everything. This offers a level of musicality and clarity that is not available from any other EQ. The EQ also incorporates features that have never before been available in a hardware EQ unit – let alone one that is Class A. The ability to blend between peak and shelf shape EQs, as well as being able to reverse the phase of a portion of the frequency spectrum, are features that just simply have not been available before.
The features took years of experimentation to develop. The first version of the EQ became unstable with certain combinations of settings. It would literally turn into a synthesizer and blast +28 dB of a distorted square wave out the output. We thought we were sunk and that I would not be able to have the flexibility I wanted while keeping the circuit stable. Patience and persistence yielded the answer. It forced us to change to a totally different approach for tackling the subtractive EQ (when you turn down a frequency). This different approach had an unintended benefit.
We realized that this approach allowed us to add the “Notch” mode and the Phase manipulation mode. The original design was simply going to have a peak mode and shelf mode. The challenge was to figure out what the character or slope of the shelf mode would be. We set up the original prototype with a trim pot to be able to adjust the slope of the shelf shape. As soon as I had a chance to play with this control, I decided it should exist on the front panel… And thus the “Shape” control was born! Each band can blend from a peak shape – to a modern shelf shape – to a vintage shelf shape – and everything in between. The Undertone Audio MPEQ-1 can literally emulate the shape or slope of any shelf EQ ever created, and it can do an endless number moves that no other EQ has ever been able to do.
After I had been using the EQ for months and months in the first UTA console, I started to realize that there were certain shapes involving combinations of bands that were being difficult to create. This was a result of the unique type of “cutting” the EQ does combined with the parallel architecture of the EQ circuit. When I had multiple bands of EQ cutting close to each other, the interaction between the bands was much more dramatic than I was expecting. We decided to make another change to the circuit and have the EQ bands be ordered both in Series and in Parallel. This ended up adding a whole other aspect of flexibility to the EQ. You can decide if you want a more parallel type interaction or series type interaction depending on which bands you choose to use. All of the EQs in my consoles were modified to incorporate
this new approach.
These significant discoveries and changes are only a few of the notable moments of endless hours experimenting, testing, and real world use that has helped refine what we feel is the best equalizer ever built. The mic preamp has gone through similar exhaustive testing, recording, and listening tests to end up with the best possible combination of components and features. The goal with the mic preamp was to have something that would could give me the vintage musicality I was used to with a Neve or EMI pre, but also have the option of running the mic pre cleaner when needed.
We came up with a mic pre wherein the user can bypass either or both of the transformers. It offers some useful tonal flexibility that now makes the UTA pre my first pick for almost every recording situation. We also added a low impedance mode by changing the strapping of the input transformer that performs extraordinarily well with passive ribbon mics. It is now the only mic pre I use with all of my ribbon mics.
