boXem A series

[boXem]

Hey!
The SMPS1200 is an unregulated SMPS, meaning that it's output voltage decreases with load. When the output voltage is too low, it will consider that it is overloaded and shut down. Fact is that the output voltage decrease is stronger when low frequencies are reproduced. So, in case of difficult loads, when reproducing low frequencies on both channels, it is possible to get the power supply to shut down. At higher frequencies, the NCx500 current limit will trigger first.
Now, to be clear, this is a behavior that is easily reproducible on bench when not taking into account distorsion preceding the shutdown. In real life, audible voltage clipping will occur well before and if these amps have tons of qualities, their clipping is audibly quite nasty. I am sure that people will lower the volume before the power supply shuts down.
So, from user standpoint the difference between a 5517/N2, a 5519/N2 and a 5519/N2M is power before clipping at 500, 600 and 700 W into 2 Ohm.

 

[boXem]

A custom installer - customer of us - was searching for an amplification solution able to deliver 1kW into 8 Ohm.

Here enter the A 5519/N2 and A 5519/N4 bridged using an Y cable (phases are already internally inverted):

 

[boXem]

Finally took the time to run some measurements on the production boards. Quite happy with the result.
High gain has a sensitivity of 2V, measured SINAD 5W 4R at 107.6 dB
Low gain has a sensitivity of 4V, measured SINAD 5W 4R at 109.2 dB
So better than competition at equivalent gain if memory serves.
@Matias do you need other data for your table?

 

[Matias]

Power at 1% THD+N 4 ohms, and price.

 

[amper42]

Finally took the time to run some measurements on the production boards. Quite happy with the result.
High gain has a sensitivity of 2V, measured SINAD 5W 4R at 107.6 dB
Low gain has a sensitivity of 4V, measured SINAD 5W 4R at 109.2 dB
So better than competition at equivalent gain if memory serves.
@Matias do you need other data for your table?

View attachment 364417View attachment 364418

Fred,
Is that the Boxem A 5517/N2?
Thank you!

 

[boXem]

It is the 2 channels {interface board + 2 NCx500} used in the A 5517/N2 - A 5519/N2 - A 5519/N3 - A 5519/N4 and A 5519/N5. Measurement was made on a A 5519/N2.

 

[boXem]

Purifi modules make their entrance in the boXem A series with 2 new amps:
- the boXem A 4222/E1 monoblock
- the boXem A 4222/E2M dual mono
Both are based on the Purifi 1ET7040SA and can be immediately ordered with 2 weeks manufacturing delay.

 

[zdykstra]

Purifi modules make their entrance in the boXem A series with 2 new amps:
- the boXem A 4222/E1 monoblock
- the boXem A 4222/E2M dual mono
Both are based on the Purifi 1ET7040SA and can be immediately ordered with 2 weeks manufacturing delay.

On the `Product Details` tab for both of those links, the Power stage(s) and Power supply rows reference Hypex related values. There are also references to A5519 on the Description page.

Are the Arthur amps coming back in stock, or are they being phased out? The site no longer has a currency selector (that I can find) - are sales to US customers still available?

 

[boXem]

On the `Product Details` tab for both of those links, the Power stage(s) and Power supply rows reference Hypex related values. There are also references to A5519 on the Description page.

Are the Arthur amps coming back in stock, or are they being phased out? The site no longer has a currency selector (that I can find) - are sales to US customers still available?

Thanks for spotting these mistake. They are corrected now. The currency selector is back.
Arthur will be back end of May with some minor external changes (slightly modernized front plate with the new logo) and more important internal ones. Can't say more at the moment.

 

[vicenzo_del_paris]

A Boxem "A" 5517/N2 (ncx500) just replaced an Boxem Arthur 3409/N2 (nc252mp) !

In the end, I ended with a Boxem A 5519/N3 to simplify my 3.2 setup.

Very pleased once again with Boxem amps !

What is impressing with these ncx500 modules, it is how loud they could go.

Tried to play some music to insane volume (-5db, high gain with 2v input) on my Focal Kanta 2, while being indeed too loud for the room, the Kantas kept up with the power and produced extremely clean sound

Little side notes:
- the trigger wakes up the amplifier but does not switch it off. The amplifier goes in standby after 10 mns without signal (same as the auto sense feature).
- 3 ncx500 modules + SMPS3k indeed draw more watts when idling compared to my previous Arthur 3409 based on nc252mp.

To summarize, happy Boxem customer here

 

[amper42]

In the end, I ended with a Boxem A 5519/N3 to simplify my 3.2 setup.

Very pleased once again with Boxem amps !

What is impressing with these ncx500 modules, it is how loud they could go.

Tried to play some music to insane volume (-5db, high gain with 2v input) on my Focal Kanta 2, while being indeed too loud for the room, the Kantas kept up with the power and produced extremely clean sound

Little side notes:
- the trigger wakes up the amplifier but does not switch it off. The amplifier goes in standby after 10 mns without signal (same as the auto sense feature).
- 3 ncx500 modules + SMPS3k indeed draw more watts when idling compared to my previous Arthur 3409 based on nc252mp.

To summarize, happy Boxem customer here

Yes, Boxem is great!
How many watts did you measure for the Boxem A 5519/N3 while idle (before 10min auto sense mode kicks in)?
Did you use Kill-a-watt to measure?
Does the chassis get warm to the touch after an hour of playing at normal volumes?
Thank you!

 

[vicenzo_del_paris]

Yes, Boxem is great! How many watts did you measure for the Boxem A 5519/N3 while idle? Did you use Kill-a-watt?
Does the chassis get warm to the touch after an hour of playing at normal volumes?
Thank you!

I have a smart plug with live wattage stats.
With the 5519/N3 it is about approx. 20w more than with previous Boxem 3409 (nc252mp).

I have to check with just the amp on the plug as currently I am many devices on that plug.

From hypex spec, it should be about 16w difference:
NC252MP : 15.5w -> 8.5 (smps) + 2x 3.5 (modules)
5519/N3 : 31.5w -> 15 (smps) + 3x 5.5 (modules)

 

[vicenzo_del_paris]

@amper42 about the chassis temperature, the top of the new A series line chassis will feel warmer than other Boxem products by design, as smps and modules are mounted on top instead being mounted on the bottom.
After a long running session, it is slightly warm but still way less than an AVR for example.
I don't have a way to measure it but the thermal design seems working very well . I am quite pretty sure that the module internal temperature is much less. It will be interesting to test it.

For example, I kept the 5517/N2 just one day. After my first listening session, the top was warmer than what I was used to with the Arthur 3409. But the bottom was completely cold.
Waiting for the 5519/N3, I used the Arthur. Following a similar session, the top was less warm but the bottom was as warm as the 5517/N2 while idle loss of 5517 is greater.