During the last couple of weeks we have discussed in depth the various preamp types available on the market. From old to new, all these preamps have some stark differences in sound, quality, design, and most importantly color - but there are also some common elements shared across the board and today I wanted to talk about utilizing these to best help your recordings, streamline your mixing, and get the most out of your microphone. Let's dive in.
Impedance and pushing the Preamp
Just like bass amps of old and new, where they had 2 separate inputs for active or passive pickups, preamps have long had the option to change in the impedance of the input, mainly for DI recording. With more modern circuits coming into play, this has been brought over to microphones more and more often, for example the Golden Age Premiere 73 and the Focusrite ISA One discussed in our recent posts. These are both transformer preamps, however many tube and solid state preamps also include this option. Because microphones draw a low current at their output level, we recommend a high impedance at all times. Low impedance can affect high end clarity and the overall sound of a microphone, and simply put, won't allow it to operate to the best of its ability.
A better option to get the color you want is to push the preamp. As we've discussed in the last two posts, THD is important to deciding the harmonic distortion on your tracks, and pushing the preamp input/output stages, depending on preamp, can add some beautiful color to your microphone and help it pair perfectly. Just be sure not to confuse THD with clipping - if the lights go red, turn down instead!
Gain Staging, Inserts and Pads
To this end, a lot of sources we record can make preamps clip furiously - if that's what you're after, cool - but I have always been a fan of clean recording, subtle harmonics, and most importantly, control. Pads can be a god send here. Using an input pad can save you in most cases, especially when the microphone doesn't have one built in and you're left wondering how to record a drum kit where each hit sounds like a small atom bomb dropping. Output pads are sometimes integrated into transformer based preamps like 1073 clones for example, because an input transformer can cook the signal rather hot.
This can also be super helpful when adding inserts into the preamp signal. The output of most units has a small switch that allows -4db or +10db to normalize the output signal, but let me describe my current vocal chain and how I avoid too much complication and climbing under my desk:
JZ Black Hole BH2 → Golden Age Premiere 73 input between 20-50% → 1176 FET Compressor inserted and set as hard as I'd like to smash the signal, makeup adjusted for any level loss during compression → Back into the Premiere 73 with the output pad engaged and output dialed out near to full.
The output pad saves me here as I can tame the signal with compression and control it. Instead of adding large levels of noise and having the sound of the output transformer running cold, subsequently missing the life we all know and love from 1073 preamps, I've run the transformer at max - but because the signal has been lowered prior to the transformer doing anything, the level is much more controlled so I can record with very low noise and no clipping. Level matching is incredibly important when using inserts and focusing on the accuracy of this will only help you down the line - for example you move to a desk where the workflow is infinitely more complicated, or if you focus on mixing where gain staging will affect every single decision you make in order to not fall into the 'loud is better' trap.
Lastly, filters are far too absent from so many recordings I'm sent each year, and it seems an intervention is needed. A lot of microphones have filters built into them, but more often than not, like our BH2 and Vintage series mics, the design doesn't always allow for switches.
Instead, preamps have these switches and it's imperative you use them, just like the input and output pads I just discussed. More often than not, the Cut 80 Hz filter is one of the first on the front of the design of many preamps. You should engage this for your Guitar DI recording, Vocal recording, Mid range Brass, Violins, Snare, Overheads, you get the picture - anything that's not bass heavy and doesn't need that nasty rumble, should be cut below 80 Hz.. It can stop you clipping the signal, which is a good enough reason on its own to engage this little button, but it can also speed up your workflow at the mixing stage, as it controls the low end information straight into the box. Knowing you've done this allows you to make more precise movements regarding the low end, rather than having to mix in autopilot, making repeated moves for almost every track.