Behringer EP2500 Professional Power Amplifier

I'll start with an overview of the unit pictured below:



The unit is built to a good standard, the metal work is of good quality and the PCB's are of a suitable grade.

The internal cabling is good for the PSU circuit and associated connections however I feel some screened cable would have been a better option for some internal signal interconnects.

The unit itself looks well and offers the visual appearance of a more expensive amplifier.
The rear has all the info silk screened onto the back panel so setup is very easy and straight forward, quite why many users need to seek further information about DIP settings surprises me as the information is very plain detailing which DIPS do what. (See image below)

Before I continue on various details I will offer a look-down view of the internals which indicate a clean logical layout with enough open space left to store a few sausage rolls on those long cold gigs we find ourselves doing.

Now onto a few minor points I thought could be improved upon:



The Transformer is of a good quality recognised brand with separate windings for each channel drive, my only improvement here would be to move the heatsink and PCB assembly towards the centre and fit two slightly smaller transformers into the unit thus achieving a true dual channel amp with separate power supplies, thus allowing for totaly redundancy should one side completely fail.

Also the Bridge rectifiers are substantial for the job in hand and there are 4 fitted into the EP2500 by means of a nut and bolt directly through the base plate or chassis, this give a secure fixing as well as providing efficient cooling.

The next item is the Speaker output assembly.

This amp is fitted with Speakons which are the Neutrik ones, so no problems with quality there and it also has Binding posts which really only suit installs. Personally I would have welcomed the absence of the binding posts.
The thing I think could be improved is the method in which the PCB is supported to the back panel. Next to the binding posts the PCB is bolted in place using some pillars, however next to the Speakons it is merely soldered in place. Bearing in mind the forces that can be applied when inserting, twisting and releasing speakons I would like to have seen PCB Pillars on both sides.(see image below)

Next on the virtual tour of the EP2500 internals are the signal input connections

Here we have the choice of using Stereo 1/4" Jacks or 3-pin XLR's.
The good thing here is they are simply wired in parallel, meaning you can use the XLR's as the main input and use the Jacks to daisy chain the signal to a second amp or more.
I measured the continuity between the sockets and concluded they are directly connected.
As can be seen in the adjoining photo the Jacks are bolted to the rear panel as would be expected with their Sleeve nut and the XLR are secured with two screws each making them more robust than the speakons mentioned earlier.

This brings me to the internal signal loom

Here Behringer have opted to use a flat ribbon cable, sure this is acceptable and provided the screening effect of the case is maintained no apparent problems will arise, however due to the nature of harmonics in any power driven circuit I would like to have seen screened cable used for a signal run of this length so close to the actual power circuits. The extra costs would have been fractions of a pence on the scale of their manufacturing per unit and provided that little piece of extra margin against signal colouration, the ribbon can be see in this photo running against the side of the amplifier, so for those with obscure mounting habits, do not go drilling or screwing through the Right side of the amplifier case without moving this ribbon first.

Finally we move to the component level

On the whole we find reasonable components, nothing special in reality just well chosen items that hopefully will provide the end user with many years of problem free service.
There are 4 power caps per channel obvisouly fitted in series per voltage rail which is designed not to exceed 120V per rail.

The outputs use the ubiquitous MOSFET topology and form a Class-H amplifer stage. The only thing I can find to comment on this area is the use of only one thermal sensor per channel which is secured under the very first FET, so if another output FET developed a fault and started over-heating it might be a delayed fault before it is shown on the front panel, however on a design such as this I am sure the circuit will detect the rise in current consumption under such a condition and shut the channel down accordingly.
This presents us now with the final two photo's of which show the Capacitors for the Right Channel and the First bank of MOSFETs for the Left Channel.