Rolls PM50S Personal Monitor Amp

Control your own level in your cans, on-stage or in the studio

By Phil O'Keefe


"More me please." Anyone who has mixed live sound or tracked musicians in the studio is probably very familiar with the phrase. Musicians need to be able to not only hear the monitor cue mix, but their own parts in order to perform their best. Giving them the ability to control their relative volume level in the mix not only frees the engineer up from having to do the adjustments for them, but more importantly, it allows the performer to achieve the balance that is most comfortable for them - and that usually results in happier musicians and better performances.

Rolls has long been building handy little "problem-solver" boxes that allow musicians and engineers to address issues such as this. One such box is the Rolls PM50s Personal Monitor Amp. This affordable little box is designed to help with the "more me" issue. Let's take a look at the details.

What You Need To Know

• The PM50S is essentially a small mixer and headphone amplifier in one compact unit.

• The mixing functions are fairly basic and very straightforward. There are two knobs - one, labeled "Monitor Level" that adjusts the level of whatever is connected to the 1/4" TRS stereo/mono Monitor Input jack, and a second knob labeled Mic Level, for controlling the level of whatever is connected to the Mic In (microphone input) jack.

• A Mic Thru jack allows the Mic In signal to be routed out to the recording or PA mixer. Worried about tonal changes or phantom power? Don't be! There's no change to the tone of the microphone, and the mic can still receive phantom power from the mixing console through the hardwired pass-through of the PM50S's Mic In and Mic Thru jacks.

• Power is supplied to the unit via an included DC power adapter. The adapter uses a 2.1mm center-negative plug, and the PM50s can operate on anything from 9-18V DC. A power LED next to the Mic Level knob illuminates when the unit is powered up. A Rolls PS16 can be used as an alternate power source - more on that later.

• The most obvious use for the PM50s is as a "more me" monitoring solution. For example, a singer can use one when tracking to adjust the relative levels of the cue mix and their own mic in their headphones. A great cue mix that the singer is comfortable with can make a huge difference in their performance, and with the PM50s, they can take control of their own monitoring volume levels.

• You can also use it with instrument microphones. For example, a saxophonist can use it to adjust the level of the sax mic in their headphones relative to the rest of the cue or monitor mix. 

• While it's not designed to accept instrument-level input directly, a direct box can be used to run an instrument into the Mic In on the PM50s, allowing bass players and other instrumentalists to control how much of themselves they hear in their headphones.

• Drummers who need to monitor the main monitor mix as well as a click track from a drum machine or other source can feed the output from the drum machine into a direct box and run that into the Mic In on the PM50s. Not only is this great for live applications, but can also reduce drummer frustration in the studio by allowing them to set the exact balance of cue mix and click that they prefer in their headphones.

• There is plenty of gain on tap to drive most headphones and ear buds to very loud levels. The overall sound quality of the monitoring is quite good, with low noise levels and a full-bandwidth frequency response.

• The optional MSC106 allows the PM50s to be mounted directly to a microphone stand.

Limitations

• While the PM50S supports a stereo line input for the Monitor mix, stereo sound sources from the musician are not supported - just a single mono Mic Input. 

• This is also potentially an issue when attempting to use the PM50S with a musician who sings and plays at the same time. For a singing guitarist who needs to monitor both their vocals and guitar simultaneously, the headphone level of one or the other would need to be controlled at the mixing console, while allowing the musician to control the level of the other part with the PM50s.

• While it can play back stereo monitor input signals, you're still limited to one mono mic input on the PM50s. You can use that with an instrument by using a direct box to feed it into the PM50s, but that leaves you without the mic input for a vocal (or instrument) mic. For players who need to be able to monitor their instrument as well as a vocal/instrument mic simultaneously, Rolls makes the PM351 Personal Monitor System, which allows you to adjust the relative levels of a mic input (with hard wired pass-thru), a 1/4" TRS stereo/mono instrument input, and 1/4" stereo/mono monitor mix input in the headphones.

• Unfortunately the DC adapter's cable is pretty short. An optional accessory, the Rolls PS16 Power Center (about $50 "street"), can provide power for multiple PM50s / PM351 units while also distributing the monitor signal to them - all through standard 1/4" TRS cables - thus reducing the number of wall wart adapters needed to power everything while simultaneously allowing individual PM50s units to be moved much further away from a power source.

Conclusions

This is one handy, clever, cost-effective and very useful little box. Every studio should have at least a few of these on hand, and drummers and live sound techs should strongly consider owning one too. Church musicians, theatrical musicians / orchestra pit members and other live performers who need to keep on-stage levels under control and who don't mind using headphones or earbuds / in-ear monitors while playing will also appreciate the utility and effectiveness of the Rolls PM50s for live use. 

The PM50s is built rock-solid, pumps out prodigious amounts of volume, sounds great, and saves time… and most importantly, it allows musicians to better hear themselves and to be more comfortable with their cue mix because with the PM50s they can easily control it themselves. Comfortable musicians who can hear themselves tend to play better than frustrated ones who can't hear what's going on. That's always a huge plus in my book, and in many situations, the PM50s is a nearly ideal tool that will allow them to experience just that. Short of getting a far more expensive system that allows for individual control of multiple inputs, this is one of the best solutions whenever someone asks to hear "more me", and is highly recommended.


Resources

Musician's Friend Rolls PM50s Personal Monitor Amp online catalog page ($70 MSRP, $44.95 "street")

Rolls PM50s product web page


Specifications

Inputs: -20dB max XLR 1k balanced, 20dB monitor
Outputs: 1/4", and 1/8" (3.5mm) 8 ohm or greater headphone outputs
Gain: 20dB 1/4", 50dB XLR
Bandwidth: 20Hz - 20kHz
S/N Ratio: 90dB
Power: 9-18V DC
Current Draw: 60ma nominal, no load 15V DC
Size: 3" x 2.5" x 1.25"
Weight: 1 lb