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Review: Ashly Audio pêma 4250

A powered processor for zoned sound systems. 11/03/2010 10:30 AM Eastern

Review: Ashly Audio pêma 4250

Nov 3, 2010 2:30 PM, By John McJunkin

A powered processor for zoned sound systems.




Ashly Audio pêma 4250

As we look back on the audio technology of yesteryear, sometimes we smile about how basic and simple some of it was. Imagine consoles with no moving faders, onboard signal processing, or recall. Or imagine near-field studio monitors with no amplifiers or DSP. OK, I’m being a little facetious here, but a world without certain audio technology conventions such as presets for outboard effects processors is unimaginable in the 21st century.

For a moment, imagine dialing up dozens of parameters with only knobs in a fast-paced live-sound environment—a daunting task at best. We have grown very accustomed to things that didn’t even exist 40 years ago, and didn’t become commonplace until 25 or 30 years ago. I’m curious as to at what point in the future we’ll fondly remember amplifiers without signal processing, matrix mixing, and network control. We’re definitely headed down that road.

There are still plenty of pure power amps, but increasingly, amps are incorporating an expanding spate of digital signal processing, internal mixing options, and remote control via networking. I know some will kvetch about “more things to go wrong” and certainly, the likelihood for failures increases along with complexity, but I would respectfully submit that the additional sophistication is worth it in the case of amplifiers. Ashly Audio has introduced the pêma (Protea Equipped Media Amplifier) line of amps, and these units do indeed feature substantially more sophistication than a plain vanilla amplifier. I evaluated a pêma 4250, and I discovered a useful device that contractors and integrators should consider.

Ashly touts the pêma series as “the world’s first powered processor.” It is debatable as to whether it’s an amp with processing or a processor with an amp, but either way, it’s intended primarily for zoned sound systems. There are four amps available: the 4125, 8125, 4250, and 8250. The leading figure in the designation refers to the number of amplifier channels the unit offers. The remaining three figures refer to the output power of the amplifiers, either 125W or 250W (double that available by bridging). Multiple configurations of each of these four basic models are available, with a 120VAC or 230VAC power mains option; a CobraNet or EtherSound networked digital audio option; and three constant voltage options of 25V, 70V, and 100V.

I evaluated a pêma 4250 with EtherSound and standard low-impedance outputs. All units offer eight inputs (either +4dBu balanced Euroblock or summed mono -10dBu RCA inputs for consumer or prosumer devices). All eight inputs have mic preamplifiers that deliver +15V phantom power (switchable in 4-channel blocks), and channel 1 can be configured as a transformer-isolated -20dBu TEL-PBX 600Ω input. The unit is controlled remotely by either Ashly’s Protea software or Ashly’s NE Ethernet, or by serial remote controllers. Although the system I evaluated did not include remote controllers, I’ve had prior experience with them, and they work nicely, offering some pretty sophisticated programmable control in particular with the neWR-5 controller. Although all parameters are accessible from the Protea control software, the pêma front panel also offers signal attenuation.

Owing to the intended remote control of all parameters, the pêma’s front panel is sparse and simple. At the left is a large power switch and LED indicators for power, standby, protect (indicating voltage or temperature faults), disable, and communications status. A cooling air-intake grille is situated in the middle of the front panel, and to the right are the aforementioned attenuator knobs, along with metering and current, temp, and bridge status LEDs for each of the system’s amp channels. From left to right, the rear panel of the pêma features a 10/100 Ethernet jack (RJ-45); a digital I/O section; and eight inputs, each with a balanced Euroblock connector and two RCA inputs. Above the inputs are the system’s preamp auxiliary outputs. To the right of the inputs and auxiliary outputs are the system’s main speaker outputs, again in the form of Euroblock connectors. Below those are logic and control-oriented Euroblock connectors, and finally in the upper right hand corner of the rear panel is the power mains inlet.


Review: Ashly Audio pêma 4250

Nov 3, 2010 2:30 PM, By John McJunkin

A powered processor for zoned sound systems.




The robust hardware of the pêma system is controlled by the comprehensive Protea application, which is unfortunately only available for the Windows platform. I was able to very easily connect the hardware to my computer and link it quickly. Once it was coupled, I had complete control of the system’s matrix mixing functions and powerful DSP. The system offers input source and gain selection, along with fully appointed brick wall limiters, compressors, autolevelers, ambient noise compensation, duckers, gates, gain, parametric and graphic equalizers and filters, feedback suppression, crossovers, delays, metering, and signal generation. The dynamics processors are sidechainable and offer comprehensive parametric control. The software also facilitates the use of up to five user IDs and associated passwords to accomplish system security, and also an event scheduler, with up to 100 events over a maximum one-week event calendar. The time resolution for events is 1 minute, and events can recall presets, change power, mute channels, select output sources, and change levels. The Protea software also facilitates the setup of automixing for PA and paging purposes. This software is comprehensive and powerful, and the graphical user interface clearly presents all the information about the system.

Internal audio is handled at up to a 96kHz sample rate, which with a Nyquist frequency of 48kHz, is somewhat overkill for most restaurant, retail, church, school, and governmental applications, but it’s available for applications that do require high-resolution audio. The 32-bit Analog Devices Sharc processors in the system provide high-quality audio indeed, and the processing algorithms are well-written to exploit the power of the Sharc hardware. The amplifiers are of great quality as well, so the entirety of the signal chain passes an excellent, clear signal. The processors facilitate a lot of control over signals in terms of dynamics, EQ, and automixing, making the pêma a good choice for installs where a lot of paging and PA is necessary. The Protea software grants clear, detailed control over the system, something I like very much; I want to have complete, unfettered access to all parameters and clear, meaningful feedback from the system. Pêma is also flexible in terms of hardware remote control, enabling the designer to create whatever custom scheme is required for the install. In summary, I’m impressed with the pêma system, and I definitely recommend taking a look if you need robust processing along with quality amplification.

Product Summary

  • Company: Ashly Audio
    www.ashly.com
  • Product: pêma 4250
  • Pros: Robust software-controlled DSP/amplifiers.
  • Cons: Protea software only available for Windows.
  • Applications: Distributed audio for restaurants, retail, houses of worship, schools, and government.
  • Price: $4,140

Specifications

  • Input sensitivity: 6.2dBu
  • Voltage gain: 26dB
  • Damping factor: >250 (8Ω load, <1kHz)
  • Distortion: <0.5% (THD-N)
  • Channel separation: -80dB
  • Signal-to-noise: >105dB
  • Frequency response: 20Hz-20kHz ±1dB
  • Balanced input impedance: 4.8kΩ
  • Maximum balanced input level: +21dBu
  • Unbalanced input impedance: 3.16kΩ
  • Maximum unbalanced input level: +11dBu
  • TEL-PBX input impedance: 3.9kΩ
  • Maximum TEL-PBX input level: +21dBu

John McJunkin is the principal of Avalon Podcasting in Chandler, Ariz. He has consulted in the development of studios and installations, and he provides high-quality podcast-production services.


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