Radial Power Pre- Pre Amp


The PowerPre is truly a marvel. Plug it in and you will be amazed at the warmth and clarity, the detail, the range and the total absence of noise. But getting there was no easy task…

It all began with an idea… to create a great sounding preamp that would not be 'pigeonholed' into a specific task. While doing our market research, we quickly discovered that natural sounding mic preamps do not sell. Folks want character. Engineers like to match different mics and preamp combinations with different singers to capture a particular character. Flat sounding mic preamps are boring. They may be boring, but truth is… they are essential. Our argument is simple: if you do not like the sound of that 1962 Gibson Hummingbird… why not simply go grab your 1953 Martin? On the other hand… if you only have three mics in your closet and none sound quite right, what do you do?

This got us thinking… how could we create a mic preamp that could magically enchant the most exotic tones out of any given microphone while allowing the engineer to quickly capture 'the magic track'? At the end of the day, it is really about capturing the very best performance… the moment. So a great mic preamp should be easy to use, quick to set up and deliver great sound with immediacy.

If you look at the very best mic preamps from years gone by, some such as those made by Neve are absolute standouts. These employ discrete components and a particular transformer to create the sonic signature. We felt that there was no point to reinventing the wheel. Let's be clear: the PowerPre is not a Neve copy. There are plenty of those on the market to choose from. Instead we created a unique circuit using 100% discrete components and combined them with a Hammond broadcast transformer. Old timers will remember Ward-Beck broadcast mixers. These were legendary for their warmth and tone. You guessed it; they used Hammond transformers.

So far so good… we created a spectacular sounding mic pre that had an abundance of natural character. We then looked at how we could introduce some 'instant gratification' by messing around with the transformer. We tried changing the way it was loaded along with various other schemes. Truth is… we could not discern enough of an improvement or change to make this approach practical. We did not want to put features in that could only be appreciated by the very few that are blessed with 'golden ears'. We wanted the PowerPre to deliver great sound right out of the box but enable the engineer to quickly adapt the tone to address common problems with microphones and performers. The Vox control is basically a 3 position preset EQ with very subtle curves. Breath delivers extra harmonic content in the high end to accentuate a male voice, 12 string acoustic guitar to add some edge so that the track cuts through. Punch is designed to thicken the soup! You can fatten a thin female vocal track, add extra meat to a rhythm guitar or accentuate the bass so that it does not sound too muddy. The high pass filter (low cut) is designed to enhance the recording by reducing unnecessary resonance. When the Vox is set to Linear… the EQ is removed from the circuit.

We then started to look at the front end and the volume control. For whatever reason, the volume control on the first prototype was not 'normal'. We have since discovered that most mic preamps suffer from this same problem whereby when you turn the level up… nothing happens until the very end. It is not smooth and linear. Why? Well it turns out that this is due to the limited types of potentiometers that are 'off the shelf' and the designers attempt at reducing background noise. Sorry. Not good enough. Radial is all about quality without compromise. So we started pulling various potentiometers apart and gluing them back together until we came up with a recipe called AccuState™. This delivers a smooth linear control range while at the same time reducing background noise. The AccuState front end is so amazing you do not even need a pad! As you bring up the gain it self-adjusts the input to lower noise. Fast and efficient – ideally suited to capture the moment.

We then looked at the mechanics and the feature set. We wanted the XLR on the front panel so that recording in the control room would be immediate. No fiddling around the back of a rack to find a connection or leaving an un-terminated cable on the floor which could act like a noise capturing antenna. It had to be 'plug-in-the-mic, turn up the level and record' easy to use. We also wanted 48V phantom power to be accessible so that it could be turned on when using a condenser mic. But phantom can also pose serious problems with ribbon mics. As a safety measure, we decided to recess the phantom power switch to prevent accidental toggling and add a red LED status indicator.

Even though the AccuState front end eliminates the need for a pad, we put one in anyway. We figured that some crazy engineer will decide to run a Hammond B3 through the PowerPre to capture the tone of the Hammond broadcast transformer (different companies) so the pad was given a home. The 180º polarity reverse was put in as a means to help phase-align two sources when recording in stereo. And as the PowerPre may well find its way onto a live stage, reversing the 'phase' can often help reduce feedback… another plus.

Finally, a lot of thought went into the 10 segment meter. Few realize that LEDs are power hungry scoundrels that can look great but also eat up valuable dynamic range. The original API* Lunchbox* spec only provides for 130mA (milliamps) of current for each slot. So if you load up a Lunchbox with too many power hungry modules, you can quickly find that the current draw is so excessive, that the sound will distort. In the solid state world, a typical mic preamp requires about 75mA to run. But each time you turn on an LED, the power demands increase by as much as 10mA per LED. Think about it: as you drive the circuit harder, you need more headroom so that the preamp does not distort but as the level goes up, you are simultaneously lighting up more LEDs effectively lowering the available current! Crunch time… that great sounding mic pre now sounds like crap - all because the designer chose to light up a Christmas tree. Instead… we simply turn on one LED at a time – turning off the showboat trail.

One final note regarding quality: The PowerPre is more affordable than other comparable preamps that are made by companies such as API, SSL and Neve. This is a choice we have made, not based on reducing quality, but on building a family of products. If we take a stand-alone Radial direct box that sells for around $200 and put it inside a 500 series box, we cannot justify charging $1000 for it. We also have a huge advantage in that we use the same parts to build our DI boxes as we do our 500 series modules. For instance we are able to buy 100,000 switches at a time direct from the factory while others buy hundreds through expensive part distributors. This enables us to employ higher quality parts, sell the product at a more modest price, and maintain a reasonable margin while still building our products in North America. Do not think for a moment that we have compromised. We have not.

The Radial PowerPre is likely the best 500 series microphone preamp made today.