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Headway EDM1 & EDB2

Acoustic Instrument Preamps By Bob Thomas
Published October 2014

HeadwayEDM1 & EDB2

Headway’s portable preamps are designed to help you get the best possible sound from your acoustic instrument, whatever it may be.

Finding the best pickup and/or microphone for any particular instrument isn’t especially difficult, since most manufacturers, both large and small, have designed pickups for almost every acoustic instrument and application under the sun. Preamplifiers are a different matter entirely, since the difference in the resonant frequencies and overall frequency responses between instruments of differing string lengths and sizes means that a preamp designed, voiced and optimised for, say, an acoustic guitar is probably not the best choice for a violin.

Originally known for their pickups, Oxfordshire-based Headway Music Audio have significantly raised their game over the last few years, not only increasing the range of pickups they offer, but also recently updating their original stand-alone two-channel EDB blender/DI to EDB2 status, as well as introducing the EDM1, a more compact, single-channel preamplifier. Both of these units are designed to cope with the preamp requirements of a variety of acoustic instruments and transducers.

Black Is Back

Designed in England and manufactured in Korea, these two preamps have an air of quality that inspires immediate confidence. The smaller EDM1 and the larger EDB2 share the same aesthetic: black metal casing with integral mic-stand mount, white legending, black switches, grey, black and green knobs, and red, green and blue LEDs. Although the preamps can be phantom-powered, the primary power sources are either a 18V, 200mA power supply or 9V PP3 batteries (one for the EDM1 and two for the EDB2). Despite the similarities in cosmetics and construction, there are significant differences in features and functionality, and it is these that will ultimately determine which of the two best fits your application.

EDM1

With its supplied belt clip, single–channel layout and small form factor, the EDM1 might appear to be aimed at the acoustic multi-instrumentalist looking for a simple device that can be tailored to suit different instruments and pickups. Whilst that is certainly true, the EDM1 is essentially a well thought-out, sophisticated and very capable preamp.

The EDM1 carries a TRS jack input that can be switched to supply 9V DC phantom power on either the tip or ring, and this can be used to supply power to an instrument’s onboard preamplifier or microphone system. This input also has a three-position switch that selects between +Hi (20MΩ), Hi (5MΩ) and Active/Low (1MΩ) input impedances, thereby allowing you to better match the EDM1 to the requirements of your particular pickup, preamplifier, microphone or line-level source.

The TRS output jack is a balanced DI output that also accepts 48V phantom power from either a mixing console or a suitably equipped preamp or amplifier. To make life easier if you’re phantom powering, Headway supply a TRS-jack-to-male-XLR adaptor. Personally, unless I was going to be using the EDM1 either on the floor or stand-mounted, I’d give the adaptor a swerve and make up a TRS-to-male-XLR lead just to keep things simple. One small point to note is that, if you lift the ground using the front-panel slide switch, this kills the phantom power from the mixer. This does seem to me to be a bit strange, if only because I’ve got a very low-cost DI or two where the ground lift does not affect phantom powering.

Headway describe the EDM1 tone control setup as a “Baxandall interactive three-band EQ section”. In Peter J Baxandall’s classic, 1952 two-band design, the controls do not interact, but in the EDM1 the three shelving bands (centred on 120Hz, 590Hz and 10kHz) are designed to overlap slightly. The bass and treble EQs have a ±12dB range, and the mid can go ±13dB. The bass control additionally adds up to 16dB of cut or boost at 45Hz to help cut handling noise, low-end feedback, mains hum and so on. A volume control plus a Mute/Live switch (with red and green indicator LEDs) is positioned just below the EQ section alongside the anti-feedback Range control.

The Range function is actually a variable 12dB/octave high-pass filter, which you can at set any frequency between 40Hz and 300Hz. Although Headway suggest that this control can help to eliminate feedback at frequencies below the chosen point, I think of it more as a voicing control for the instruments specified. To assist you in selecting a suitable frequency, the Range control is labelled with suggestions for a range of common instruments, from Bass at 40Hz to Rock Acoustic at 300Hz (see ‘Home On The Range’ box). It is worth bearing in mind that the Range control is in circuit before the EQ, so if, for example, you’re on the Rock Acoustic setting, there won’t be anything for the bass EQ band to act on.

EDB2

A thoughtful update of the original EDB1, Headway’s EDB2 is around twice the size and weight of its smaller stablemate. Although a belt clip is supplied, I’d be more inclined to mount it on either a mic stand or the floor. The increase in size brings with it an increase in facilities over the EDM1, with one possible exception that we’ll come to later.

The EDB2 is in essence a two-channel blender, allowing you to mix two sources — pickup, preamp, microphone or line-level source — down to mono on both a balanced XLR DI and an unbalanced line-level jack. The channel 1 input is on a TRS jack and, as on the EDM1, gives you the option of sending 9V phantom power to ring or tip. Channel 2 is also fed by a TRS jack, but this allows you to access the channels separately: channel 1 on the tip and channel 2 on the ring (if you plug in a stereo jack), or just channel 2 if you use a mono jack. Additionally, the second channel can come from a balanced XLR microphone input, to which 18V of phantom power can be supplied, via a front-panel three-position switch that also enables you to cut out the microphone input to reduce background noise. You also have the ability to reverse the polarity of either channel relative to the other.

Both channels 1 and 2 have their own gain controls, plus individual input impedance selection (identical to that of the EDM1). The EQ is the same interactive Baxandall type, but this time the EDM1’s three-band setup is joined by a high-mid band at 900Hz and a ‘presence’ band at 2.8kHz. In addition, there’s a semi-parametric, fixed-depth (-12dB) notch filter with variable width (five octaves to half an octave) and a range of 50Hz to 6kHz. The five-band EQ is always active and can be switched into either or both channels, whilst the notch filter, which has its own in/out switch and indicator LED, affects either channels 1 or 2, but not both together.

The Range switch on the EDB2 is about the only function inherited from the original EDB1 that hasn’t been upgraded or improved in some way. In contrast to the continuously variable cutoff found on the EDM1, the EDB2 retains the EDB1’s three-position switch, giving you the choice of voicings for violin, guitar or bass. Fortunately, because the Bass EQ band is centred at 120Hz, setting up the EDB2 for instruments such as bouzouki, tenor guitar or viola isn’t really going to be much of an issue, although duplicating the EDM1’s Rock Acoustic setting is going to require a bit of creative use of both the EQ and notch filter.

Finally, it’s worth mentioning two small tweaks that illustrate the thought that has gone into the EDB2. The first of these is an ‘iPod in’ stereo mini-jack that allows you to send a mono sum of the output of your MP3 player of choice directly to the EDB2’s outputs. The second, and an on-stage saviour for me, is the standby position on the power switch. Being able to switch power to the EDB1 on or off without causing major thumps and bangs through the PA is a real convenience.

In Use

I have a few instruments that have been fitted with active or passive pickup/mic or pickup/pickup combinations, sourced from (among others) Fishman, K&K, Barcus-Berry, Mimesis, Pure Acoustic and Sunrise. In addition to tenor and five-string banjos (I notice that for some reason the EDM1 doesn’t have a Range suggestion for these), there’s a mandolin, a mandola, a cittern, a tenor guitar and a bouzouki — plus bass, baritone, six- and 12-string acoustic guitars, an Appalachian dulcimer and the inevitable ukulele or two. Then there’s my wife’s fiddle, nyckelharpa and octave fiddle. Available amplification included my Adam studio monitors, JBL Eon G2 active loudspeakers and a Phil Jones Bass AG150 acoustic amplifier — so the EDM1 and EDB2 received a fairly comprehensive workout.

Both units produce an exemplary sound quality and manage the trick of being clean and clear without sounding sterile. The three input-impedance settings come into their own when you’re having to deal with the very different requirements of magnetic and piezo pickups, internal mics and active preamps. Switching between instruments and/or pickups on the EDM1 proved the efficiency and ease of use of its variable Range control. I really liked the way in which I could start with the Range set to the recommended position for a particular instrument, but then had the freedom to vary the high-pass cutoff point to get the best sound. On the EDB2, a combination of the Range settings and the notch filter (which is, in reality, parametric EQ with a fixed -12dB cut), together with a bit of bass EQ, got me more or less to the same point, but the EDM1 was definitely the quicker on which to get a good basic sound.

However, the EDB2 came into its own when dealing with more complex (from a sound-reinforcement point of view) sources. Most of my instruments have pickup/pickup or pickup/mic combinations (which Headway, incidentally, don’t recommend), and getting the best out of these setups does require a bit of work — which the EDB2 handled with ease. Having the five-band EQ and the notch filter available on either channel (or both in the case of the EQ) makes life so much easier. Couple those with the three-position Range switch and you’re close to my ideal acoustic preamp. The phantom-powered XLR mic input available was an extra bonus for me, as normally I’d have to also take out my TC Nova acoustic preamp to be able to use my DPA and Accusound mics on stage.

Conclusion

For simple acoustic pickup systems (active or passive) across a range of instruments, the EDM1 is, to me, possibly the best and simplest on-stage solution that I have come across to date. Other than the ground-lift/phantom-power issue, there isn’t any reason that I can think of why you shouldn’t just go out and buy one — especially if you play a couple of different types of instruments on stage. The EDM1 is so good and it is so easy to use.

If you don’t have to cope a wide range of differing instruments, the EDB2 gets very close to being a no-brainer buy, although you’ll have to balance its bulk and the little bit of effort involved in setting up a sound against the benefits of its additional facilities over the EDM1. If you’ve got only one or two instruments to worry about on-stage, or if you have a dual-source pickup system (especially if you have internal mics that need power), then owning an EDB2 makes an awful lot of sense.

Headway have been enjoying a growing profile recently, and it is really great to see a British company succeeding in a very competitive market sector. Get your hands on either or both an EDM1 or EDB2 and you’ll find out two of the reasons for their success.

Alternatives

Most acoustic preamps are designed specifically for a manufacturer’s own pickups and, as none that I know of have the equivalent of a Range control, you’ll be unlikely to find anything quite like the Headway units. There’s a good case for equivalence to be made for the Fishman Aura Sixteen and Spectrum DI, provided you use undersaddle pickups and load images appropriate to your instruments. You could also look at the D-TAR Mama Bear, but that particular unit is a serious investment for a guitar-only solution.

Pros

  • Superb sonic quality.
  • Range control covers a wide variety of acoustic instruments.
  • Switchable input impedance handles all types of active or passive pickup systems.
  • Easy to use, especially the EDM1.

Cons

  • The EDM1 can’t be phantom-powered from a mixer when its earth is lifted.
  • Other than that, there’s really none!

Summary

Two extremely useful acoustic preamps, marked by excellent sound quality, great features and, especially in the case of the EDM1, remarkable ease of use.

information

EDM1 £149.95; EDB2 £249.95. Prices include VAT.

Headway +44 (0)1869 338404

sales@headwaymusicaudio.com

www.headwaymusicaudio.com