If you can keep your head when all around you are losing theirs, the chances are you're not monitoring loud enough! Paul White listens in on Samson's Q5 headphone amp.
You must have seen that TV ad — the one where you watch paint dry for 30 seconds, then a message comes up telling you that's about as exciting as house insurance gets? Well, that ad is Oscar‑nomination material compared with headphone amplifiers. In the fun stakes, headphone amps rate right alongside mic stand clips — but just like mic stand clips, they're a vital part of any recording studio.
Virtually every mixing desk ever made has a headphone outlet, but unless you're a solo musician recording your own material this probably won't be enough. A dedicated headphone amplifier, on the other hand, allows you to take the output of a foldback send (or any other line source), and route it to a number of headphone outlets, each with its own volume control. This is clearly essential when two or more people are playing at the same time.
There are lots of fancy tricks you can do to extend the flexibility of a headphone amplifier, but the half‑rack, 1U‑high Samson Q5 delivers just the basic necessities in order to keep the price down. Indeed, this is one of the cheapest headphone amps I've come across. As is the case with most headphone amps, the Q5 is stereo and features balanced TRS jack inputs. If you were to use a single aux send to feed the unit, this would result in only one side of the phones being fed, so a global mono switch is fitted to the front panel, allowing both phones to be fed from the same source (or from a mono mix of the two inputs if a stereo feed is available).
Five separate headphone‑output TRS jacks, each with its own level control, are accessible from the front panel, and a master input gain control, doubling as a power switch, provides a means of matching the incoming signal level. However, there's no input clip LED — a facility that I would have found useful. Power for the Q5 comes from a hefty mains adaptor included in the price, and sharing the rear panel is a pair of balanced linking jacks that allow two or more Q5s to be hooked together and fed from the same source.
The audio performance of the amplifiers is actually very good, featuring a full 20Hz‑20kHz frequency response, accurate to within 1dB, and a worst‑case total distortion figure of less than 0.006%. The maximum output level is +24dB, to accommodate high‑Z headphones, and the power supply includes a voltage‑doubling circuit to maximise the available headroom.
In general, the sound quality available from the Samson Q5 is comparable with what you'd expect from the phones output of a typical hi‑fi system, and for most home recording purposes, or for overdubbing, the level is adequate. However, when I tested the Q5 with 150Ω headphones, I found the maximum level before distortion to be a little short of what I'd anticipate needing in a recording session involving drums. Lower‑impedance headphones would help, of course, but probably not by a huge amount. What's more, I found that if the input gain was advanced too far, overload distortion was evident regardless of the settings of the individual output levels. This is a perfectly normal 'gain structure' problem, but without the benefit of a clip LED it takes a little longer to figure out where the distortion is coming from. To be perfectly fair, some of the distortion may have been due to pushing the headphones too hard, but without clip LEDs there's simply no way to tell.
In the Q5 headphone amp, Samson have produced a cost‑effective solution to multiple headphone monitoring in situations where each performer needs to hear the same mix, but where the level requirements might differ. The build quality of the unit is good, and the ease of use is compromised only by the lack of a peak clip LED. Having a mono button and link sockets to add further units is useful, and, other than the possible lack of sufficient level when using some less‑sensitive high‑impedance 'phones in a high sound‑level environment, the sonic performance is as good as you could ask for. In a home studio, where most of the work involves vocals, MIDI instruments and DI'd instruments, the Q5 is a practical and cost‑effective headphone monitoring solution. If, however, you need to feed different mixes to different performers, be prepared to spend more money on a more flexible unit.
One potential problem when designing a headphone amplifier is that headphones come in a wide range of impedances, from less than 50Ω to over 600Ω. The circuitry used in the Q5 is based around a 500mW stereo amplifier per outlet, and is designed to run into virtually any conventional headphone, down to 8Ω impedance, without mismatch. However, low‑impedance phones will produce a much higher sound level than high‑impedance phones, so if you do have an odd assortment of cans in your studio, be prepared for the front‑panel gain controls to end up in totally different positions.
- Very good value.
- Nicely built.
- Good sound quality.
- Five outputs.
- Lack of input clip indicator.
- May be insufficiently loud when used with less sensitive, high‑Z 'phones.
An ideal headphone amplifier for use in project studio situations where all the performers are happy receiving the same mix.