This is a review and detailed measurements of the Crown XLS 1502 "PA" Power Amplifier. It is on a kind loan from a member who bought it new and drop shipped it to me. It retails for USD $349 including free Prime shipping from Amazon. At that price, it seems like an incredible value.​

I have to say, while the unit looks industrial/military, it does not at all feel cheap. As expected it comes in 19 inch rack mount configuration but very shallow:Not only do you get a high power amplifier with front graphical display and such, but also a built-in DSP. It is not a fancy subsystem but allows you to dial in crossovers and such which is very handy in live sound. At may company (Madrona Digital) we use a ton of Crown amps not for hifi applications but for music distribution in the home. The built-in DSPs come in handy for limiting the frequency range, max output, etc..Unlike home units, the XLS 1502 has a built-in fan with tons of holes for ventilation as you see. Fortunately it is temperature controlled and barely came on during my nearly 50 watt soak time. And when it came on, it was very quiet.Here are the guts of the unit (click on the image for larger size):Man, is this clean! Look at the beefy mains chokes to keep noise at bay. The power supply is integrated on the same board as the power amplifier so you can't swap one to fix the unit although at these prices, getting a new unit is more economical anyway. The fan is placed not only in front of the heatsinks for the power transistors but also the output filter inductors which is nice as far as keeping them cool too.I noticed that the output stage is depopulated. Seems then that the step up model just has a few more parts in it and that is that:There are tons of connectors in the back which I let you read about elsewhere. Overall, this is jaw droppingly nice unit and unbelievable at the price that is being charged.I did a lot of searching and was surprised that there were no measurements of these units. A lot of empty reviews, yes. But no measurements. So you get to have an exclusive set of data in this review!So let's get into that.I started by cooking the unit for a while at 48 watts with kind permission from its owner:Unlike some other amps, bringing the unit up to temp ever so slightly worsens performance. There are also some interesting thermal effects from time to time represented by the spikes. Anyone who thinks they can predict what thousands of components do as they warm up should get into predicting the weather on tuesday next week, 10 years from now!Anyway, let's look at our dashboard at 5 watts of output:Sorry I did not set the reference in the FFT. But the news is there in the SINAD (signal over distortion and noise) of just 75 dB. We have seen worse but also much, much better. Gain is about 30 dB by the way.Signal to noise ratio is decent but again, nothing high-end about it:Let's look at power versus distortion+noise:So we see that the Crown XLS 1502 easily outperforms the no-name Chinese class D amp we recently tested (IRAUD350) . It has a well behaved response with sloping down curve and then onset of clipping. Power was around 336 watts @ 0.008% distortion. I say "around" as there are not enough points in these measurements to find the exact onset of clipping. The number is therefore a bit understated. Crown specs the unit at 525 watts though at 4 ohm and we are not going to get there without a lot of distortion.The hypex Hyped DIY Nc400 amplifier far outperforms the XLS 1502 . It has far lower noise and distortion although not as much power before clipping. It costs nearly four times as much though.I thought I do a comparison against the Behringer A500. The A500 feels a lot more cheaply made but is also priced at $199:We see that the Crown XLS 1502 is better in every regard with lower noise and much more usable power before clipping.I thought the continuous power would be a walk in the part for the XLS 1502 but did present a surprise:The red "thermal" light came on the front panel but instead of shutting down, the power was reduced a bit. "The show must go on" seems to be the rule here and nice to see instead of full shutdown we saw with Hypex Nc400. As you see, I let the unit keep going and it went to 8+ minute maintaining that status.Frequency response was surprising but easily explainable:We have a "brickwall" style filter which indicates our analog input is digitized first through an ADC running at 48 kHz sampling, processed through DSP (or not), and then converted back to analog before amplification. Both the ADC and DAC therefore sharply limit the bandwidth to 48 kHz. I was surprised to see some roll off at 20 Hz too.Wideband FFT (without AES filter) as usual shows a lot of activity in higher frequencies:The first peak is very nicely truncated at a little less than 100 kHz to pass emissions standards (by 60 dB). Crown class I devices interleave the output stages which would explain the energy spread over four quadrants at multiples of that ~100 kHz pulses. Since the XLS 1502 has passed emissions standards I would not worry too much about them.It is hard to fathom that a properly engineered and produced mainstream brand amplifier with so much power can be sold for so little money. This is a robust but bargain amplifier designed for heavy punishment in live sound. Can it be used for hi-fi use? Sure but it will severely limit both the resolution and potentially bandwidth of upstream sources. Its best use would be as a subwoofer amplifier. If you need an all in one unit, Hypex NC400/NC500 designs are so far my choice among amplifiers tested.-------------As always, questions, comments, recommendations, etc. are welcome.If you like this review, or even if you don't but wish for me to escape the rain in Seattle and go somewhere sunny, please considerusing: https://www.patreon.com/audiosciencereview ), or https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054 ).