What is a Mic Preamp?
A Microphone preamp is a little gizmo that turns up the mic signal before you record it. You never needed to worry about them before. This was because they were built into every mixing console. But more and more studios are getting rid of their consoles so the preamp has become more important.
Preamps nowadays exist either in dedicated channel strips or as standalone units. Recording budgets and therefore studios are shrinking. As a result, the 500 series racks from manufacturers such as API have become very popular. This attraction is no doubt due to the fact that you can squeeze lots of units into a small space. There are many preamps already available for the 500 series. Furthermore, there are a lot of good DIY options.
New AML ez1081 Mic Preamps
I recently finished building some new microphone preamps from AML (Audio Maintenance Limited). The kits are named the “ez1081 Mic Pre”. They pay homage to a well-respected line of transformer-based preamps! The grey metalwork and red Marconi gain switch is a bit of a giveaway of the inspiration. So how does this new offering from AML fare?
The ez1081 mic pre units ship either pre-assembled or as a DIY kit and it’s the latter that I opted for. I should point out that everything required to build the preamp is included in the bundle. This is great because there is no need to source hard-to-find components. Compared with some of the other kits I’ve built this is a one-stop shop.
The metalwork is of excellent quality and the PCB fits the chassis like a glove. The resistors even come pre-cut. As a result this is an easy build for first-timers as well as seasoned DIY-ers. I’ve built a kit from AML before: the ez1073 Mic Pre< that I have documented in another blog post. AML build the best DIY kits available in the UK at the moment. Lastly, the documentation is very thorough and easy to follow. What’s more impressive is the gear sounds fantastic!
It took me almost 2 days from start to finish to build and calibrate 4 of these preamps. It is also worth noting that they fit in a standard API 500-series rack. I’m using the classic API 6B rackable lunchbox. The units sell for £179.95 + VAT per unit which is very reasonable and details of the units are on the AML website.
You can see a slideshow of images of the build process below:
The ez1081 Mic Pre on test…
The preamps built into my Avid C|24 console lack dynamic range and also transient response. As a result, I’m hoping that these new preamps will become my go-to choice for percussion. So I decided to road-test them to see how well they handle a drum recording.
I set up my drum kit and miked it up using 4 mics. I placed an Audix D6 on Kick – a common microphone in this application. On snare, I used a Beyer M201 – a nice contrast to the ubiquitous SM57. And finally, I used a pair of Coles 4038s as overheads because they shine in this role.
The Mic signals went through my ART S8 8-channel mic splitter. This meant I could compare preamps on the same performance. Tracks were then recorded via the ez1081 mic pres as well as the Apogee Mini MPs for comparison.
You can see a video of the process below:
So how do they sound?
I love these preamps – especially the 300 Ohm setting because this adds weight as well as openness. In contrast, the Apogees appear anaemic in this regard. This effect was far less obvious when switching the ez1081 units to their 1200 Ohm setting. As a result, it’s definitely going to be worth my while seeing how this affects recorded signals.
Above all though was that I could hear – especially on the kick drum – the beginnings of saturation. This is due to the two Carnhill transformers in the unit. In contrast the Apogees use a transformer-less design. This effect can be utilised even more by running the gain higher and padding the output. I was hearing some slight compression on the kick as well as some slight ducking after each hit.
It is annoying these preamps don’t come with an output attenuator like the ez1073. But despite this slight niggle I wouldn’t hesitate to recommend them.
To summarise though: at this price point, it’s very difficult to fault these units. They have a recallable gain switch, high-quality components and great build quality. Despite the odd niggle they seem built to last!