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Crown XLS1002 Amplifier Teardown

amirm

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I recently reviewed the Crown XLS1002 Amplifier. This is a teardown of the same. Let's get right into it with the overview shot:

Crown XLS1002 Rackmounted Pro Amplifier stereo teardown schematic.jpg


A single board contains the entire guts of the machine, sans the front panel display. Using one board lowers labor cost and increases reliability due to elimination of cables. Down side is that if you are going to do a board swap, you are basically replacing everything which likely will cost as much as buying a new amp!

Overall layout is quite logical and nice. Right side has beefy noise and EMI filtering. Once past that, the AC voltage is converted to DC, rectified, filters and then switched at high frequencies. The high frequency allows much smaller inductors to be used than the 50/60 Hz Mains transformers. The switched signal is then converted back to lower voltage DC with rectification, filtering and regulation.

The power supply then feeds the amplifier on the left, the heart of which is the TI controller:

Crown XLS1002 Rackmounted Pro Amplifier stereo teardown amplifier zoomed class d.jpg


You can buy the TI SN6112B5 ($7 in quantity) but there is no spec for it. It was a joint development between Harman and TI and likely kept as a proprietary part.

Output duty is performed by a pair of transistors on the diagonal heatsinks. They get decent air flow from the fan but obviously not optimal given the inductors that are in the way. Still, they likely do the job.

I don't like the pair of capacitors next to it which are part of the power supply. They are only rated at 85 degree C and in fwclose proximity to those heatsinks:

Crown XLS1002 Rackmounted Pro Amplifier stereo teardown teapo capacitor PS 2.jpg


If there was no fan, I would say this amp/capacitor would not last long. But seeing how the fan did not even come on and the unit ran very cool, it should be OK. In a commercial install though with uncontrolled environment, it will likely die.

For completeness, there is another pair of caps from another low tier manufacturer in the power supply:

Crown XLS1002 Rackmounted Pro Amplifier stereo teardown teapo capacitor PS.jpg


This one is well away from heat sources and the brand seems OK so should be fine.

I was impressed with the design of these beefy binding post connectors:

Crown XLS1002 Rackmounted Pro Amplifier stereo teardown speaker binding posts.jpg


These things are designed to a) stay connected and b) carry a ton of current.

Conclusions
The Crown XLS1002 has a clean design which obviously has gone through proper design and certification reviews. While I wish a better grade capacitor was used in the power supply and from a better brand, given the incredibly low price of this amplifier it is fine.

------------
As always, questions, comments, recommendations, etc. are welcome.

I know what some of you are thinking. "Amir doesn't really have a garden. He must be buying a bit of fruit here and there and pretend he does." Well, feast your eyes on the harvest from early in the week in pouring rain:

Amir Fruit Harvest.jpg


And there was a box of apple on the seat of the Quad! Had just picked the Zucchini a week ago but of course they grow like mad. Those huge ones have been sliced and are drying in the dehydrator as I type this. 14 jars of pear were preserved yesterday in syrup. I make everything from smoothies to sorbet with them.

As usual, I could use all the money I can pocket from you all so please donate using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

restorer-john

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Teapo as a brand were arguably the worst capacitor in terms of failure rate I have ever seen. Perhaps they have improved, but everything from small SMPS supplies, to CFL/LED supplies, laptop, PC ATX, and network hardware used them and paid the price in dead equipment.

Jamicon have always been a middle tier, but decent capacitor brand. I've never seen a catastrophic Jamicon-caused failure event.

There appears to be an unpopulated place for a pair of dual (half bridge) diodes on the lower heatsink. Perhaps not-needed flyback.
 

martin900

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Feels like yet another amp with planned life cycle, either a capacitor will die and take out the PSU or it might have a 'killswitch' IC built in.
TEAPO was a low tier capacitor brand most commonly found in cheap computer PSU's, not sure how good they're now.

For home use I think I'd rather grab a dirt cheap (100-200 bucks) old Hitachi MOSfet beast like a Harrison, HH or even Ashly.
 

pavuol

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Finally we get to know that Amir is not Nwavguy as some speculated, his real name is Ivan Vladimirovich Michurin Jr.

Anyway, there should be a switch on the back for "fan always on" in this type of device, imo.. (I have such switch on the back of my computer PSU, namely Seasonic Focus)
 

Colonel7

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I recently reviewed the Crown XLS1002 Amplifier. This is a teardown of the same. Let's get right into it with the overview shot:

View attachment 85008

A single board contains the entire guts of the machine, sans the front panel display. Using one board lowers labor cost and increases reliability due to elimination of cables. Down side is that if you are going to do a board swap, you are basically replacing everything which likely will cost as much as buying a new amp!

Overall layout is quite logical and nice. Right side has beefy noise and EMI filtering. Once past that, the AC voltage is converted to DC, rectified, filters and then switched at high frequencies. The high frequency allows much smaller inductors to be used than the 50/60 Hz Mains transformers. The switched signal is then converted back to lower voltage DC with rectification, filtering and regulation.

The power supply then feeds the amplifier on the left, the heart of which is the TI controller:

View attachment 85009

You can buy the TI SN6112B5 ($7 in quantity) but there is no spec for it. It was a joint development between Harman and TI and likely kept as a proprietary part.

Output duty is performed by a pair of transistors on the diagonal heatsinks. The get decent air flow from the fan but obviously not optimal given the inductors that in the way. Still, they likely do the job.

I don't like the pair of capacitors next to it which are part of the power supply. They are only rated at 85 degree C and close proximity to those heatsinks:

View attachment 85010

If there was no fan, I would say this amp/capacitor would not last long. But seeing how the fan did not even come on and the unit ran very cool, it should be OK. In a commercial install though with uncontrolled environment, it will likely die.

For completeness, there is another pair of caps from another low tier manufacturer in the power supply:

View attachment 85011

This one is well away from heat sources and the brand seems OK so should be fine.

I was impressed with the design of these beefy binding post connectors:

View attachment 85012

These things are designed to a) stay connected and b) carry a ton of current.

Conclusions
The Crown XLS1002 has a clean design which obviously has gone through proper design and certification reviews. While I wish better grad capacitor was used in the power supply and from a better brand, given the incredibly low price of this amplifier it is fine.

------------
As always, questions, comments, recommendations, etc. are welcome.

I know what some of you are thinking. "Amir doesn't really have a garden. He must be buying a bit of fruit here and there and pretend he does." Well, feast your eyes on the harvest from early in the week in pouring rain:

View attachment 85013

And there was a box of apple on the seat of the Quad! Had just picked the Zucchini a week ago but of course they grow like mad. Those huge ones have been sliced and are drying in the dehydrator as I type this. 14 jars of pear were preserved yesterday in syrup. I make everything from smoothies to sorbet with them.

As usual, I could use all the money I can pocket from you all so please donate using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Save yourself from the zucchini giants by picking the flowers early, stuffing them with herbed goat cheese, and pan frying them...
 

YSC

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Why can’t they just charge extra with more reliable parts...
 

MediumRare

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Teapo as a brand were arguably the worst capacitor in terms of failure rate I have ever seen. Perhaps they have improved, but everything from small SMPS supplies, to CFL/LED supplies, laptop, PC ATX, and network hardware used them and paid the price in dead equipment.

Jamicon have always been a middle tier, but decent capacitor brand. I've never seen a catastrophic Jamicon-caused failure event.

There appears to be an unpopulated place for a pair of dual (half bridge) diodes on the lower heatsink. Perhaps not-needed flyback.
John, what would you do to improve on the one channel with higher output distortion at 4 ohms? The THD was more typical and lower at 8 ohms.
 

PeteL

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Why can’t they just charge extra with more reliable parts...
I am sure they do, Crown have a series in many price brackets. They also don't have a history of being unreliable. The goal here was to be cheap, but yes, if someone is willing to pay more for a better amp, they are able to satisfy your will.
 

PeteL

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John, what would you do to improve on the one channel with higher output distortion at 4 ohms? The THD was more typical and lower at 8 ohms.
Just intuitively, those 2 unshielded power links for the fan passing right above the exposed audio signal post of the right channel jack connector, almost touching, is not something I like. Even tough XLR was tested, I don't see relays there at the inputs.
 

MediumRare

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Just intuitively, those 2 unshielded power links for the fan passing right above the exposed audio signal post of the right channel jack connector, almost touching, is not something I like. Even tough XLR was tested, I don't see relays there at the inputs.
So, what to do to fix that?
 

PeteL

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So, what to do to fix that?
Not sure, as I said it's only intuition and yes John would be a better reference than me. Maybe it worth trying longer leads and redirect them, maybe it won't change a thing. In all cases, all electrical motors are inductive to some extent. and generally the audio signal is what you want to isolate as much as you can. Even the fan itself I find it close, too close, and it does seam to be the right channel that perform less.
Edit: Maybe just unplug it and see if it makes a difference in the measurments? And if it does, maybe for your use case it's not even necessary? It's still a class D amp.
The rise of distortion in 4 ohms seams to start at 50W, maybe when the fan starts rolling? Maybe in 8 ohms, with less current draw, it doesn't start at all in the test?
 
Last edited:

Kachda

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Teaco... rhymes with cheapo...
 

Billy Budapest

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I am sure they do, Crown have a series in many price brackets. They also don't have a history of being unreliable. The goal here was to be cheap, but yes, if someone is willing to pay more for a better amp, they are able to satisfy your will.
The Crown 2502 was measured relatively recently and had similar mediocre noise and distortion performance.
 

EJ3

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The Crown 2502 was measured relatively recently and had similar mediocre noise and distortion performance.

In the 70's & 80's CROWN had some stuff that sounded real good (possibly even great). Without testing, I don't know for sure but it seems that I have not heard any recent CROWN equipment that sounds even real good.
I know that my hearing is not as acute now but I still seem to have a sense of what sounds real good to me. Some equipment that I have had refurbished from back then still sounds real good (some even better & some about the same). Other things that didn't sound good to me then, still don't, even if they have been refurbished.
I "may" not still be able to tell great equipment from greater equipment but I seem to still be able to tell good and great equipment from not so good & great equipment. CROWN may still produce some really good or great equipment and I have just not run across it.
 

restorer-john

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The rise and shape in distortion in one channel is similar to another Class D @amirm tested recently. Can't rememeber which one. But the pattern was the same IIRC, but for both channels.

As they are both channel driven tests, we don't know if one is affecting the other or the results are the same in single channel driven modes. The placement of the switchers, the output inductors and the power supply filter caps mean one channel will have different impedance traces no matter what. As the issue manifests at elevated power, where a lot more current is flowing, I'd put my money of poor trace layout, especially in relation to the output inductors and filters. One takes a way more direct path (if you can call it that).

There also appears to be output inductor feedback traces running alongside high current traces and we don't know what's on the back side of the board in even how many layers it has.

I know there are arguments against identical or mirror imaged layouts, but interchannel performance is usually very consistent in those designs. PSU in the middle, channels either side with the input circuitry away from mains cabling. Plenty of low impedance, twisted cables, shielding where needed, and canned/potted transformers or truly excellent SMPSs. Look at the Benchmark for example.
 
Last edited:

YSC

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You get what you pay for.
Well, when decent and great capacitors are available dirt cheap nowadays I don’t really see any justification on using some 85 degrees rated famous crap caps I don’t expect very expensive audiophile ones but in any device which will get anywhere near hot shouldn’t use those crap branded caps anyway
 
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