We thought you might be interested in how we ensure that every Mack amp is ready for the real world of gigs, recording sessions and late night bedroom jams!  You might be surprised at the level of quality testing that we submit our amps to before we box them up and ship them on their way to a life of producing inspiring tone.

The first thing to note is that we take quality and safety testing VERY seriously.  There are three stages to the process: a bench test, a safety certification inspection and playing tests.

Every Mack amp undergoes a 59 point bench test before it's "OK" sticker is affixed to the circuit board.  This test involves checking the electrical integrity of the amp from the power supply to the output transformer.  Key components are measured in-circuit to verify their integrity before the power is turned on. 

Next, with the power on, voltages are checked throughout the amp - without the tubes in place.  After installing the tubes the same voltages are re-checked. 

The final stage in the bench test involves connecting a signal generator to the amp input, a dummy load to the speaker output to simulate a speaker and an oscilloscope and a distortion analyzer across the dummy load to observe the amp's output signal and determine if it is operating exactly as it should.  The amp is put through it's paces while observing and checking its output against a standard set of performance criteria.

If all of the above tests produce results that are within standard operating parameters an OK sticker is applied to the circuit board and the amp is ready for its safety inspection.

The safety inspection is conducted by a third-party company that is brought in to inspect each batch of Mack amps.  True to the Mack philosophy of building amps in such a way as to reduce cost - and price - we build our amps in batches.  When a batch of amps has passed the bench test, we call in the inspector to do his thing.  This results in each amp chassis having an ETL sticker applied.  This is the equivalent of a UL or CSA sticker and confirms that the amp has been designed and built in conformance with all applicable North American electrical safety standards.

Next is the fun part!  Each amp is plugged into a cab, fired up and played.  The chassis is then scheduled to be 'stuffed' into its cabinet.  The final step of the quality process is to play the amp again just prior to shipping ... this final playing test is conducted by me - I personally ensure that every amp that goes out the door performs as I expect it to for each of our customers.

Hopefully, this glimpse into the inner workings of Mack shows that we are as serious about producing a quality product as we are about producing stellar tone!

Virtuoso Tone Without The Prima Donna Price!