boXem A series

[boXem]

Hi,
Thanks for the reply. No, I don't have a use case. But I think 210 watts per channel isn't 380 watts. And I just like to have more performance. It's just a good feeling to drive a Porsche 911.

Then wait for the Purifi 1ET9040BA based amp. It's just a good feeling to drive a Ferrari

Hi, by the way. Ampollos Mono Amp 7040 Purify delivers 250 Watts/8 Ohms. What is the reason for the differnce to yours (210 Watts)

Apollon Audio Purifi 1ET7040SA M Monoblock Amplifier

The Apollon Audio 1ET7040SA M Stereo Amplifier is built around the powerful Purifi 1ET7040SA amplifier module in a very compact and light weight design with amazing clarity and brutally linear sound.

apollonaudio.com

It's a good question. Performance is power supply supply limited and they use the same power supply as we do.

 

[Stereoed]

Then wait for the Purifi 1ET9040BA based amp. It's just a good feeling to drive a Ferrari

It's a good question. Performance is power supply supply limited and they use the same power supply as we do.

When will you offer the 1ET9040BA in your monos?

 

[boXem]

When will you offer the 1ET9040BA in your monos?

When Purifi will decide to sell it to their customers ...

 

[Stereoed]

When Purifi will decide to sell it to their customers ...

Ahh. I understand. I am whatching you

 

[Stereoed]

Hi,
another question. What is meant when you write in your news "In early 2024, a larger case will enter production, allowing two, three, four and five channels variants A-Series" ?

 

[boXem]

Hi,
another question. What is meant when you write in your news "In early 2024, a larger case will enter production, allowing two, three, four and five channels variants A-Series" ?

That the case used for the 5517/N2 and 5519/N1 has a 233 mm width and that a full size (435 mm) case will come and allow new variants.

 

[Acerun]

Two levels gain setting (boXem stage II buffer only)​

A switch on the rear of the amplifier allows you to set two different levels of gain. Depending on the output capability of your source (pre-amplifier, processor or DAC with volume control) the system gain structure can be optimized for two main targets.
The first is to have the lowest noise, the second the smoothest volume setting as possible.
While the noise levels of modern audio gear has become so low that noise optimization for home audio is often purely academic, having a smooth volume control is something we find so enjoyable that it was our main motivation for integrating the gain control switch.

Can you explain this more? I don't understand what I would be getting and what the dependency is to the output level of the source.

I would be using one with a Denon x8500h AVR if that helps

Edit: I do see 2.6v input sensitivity and 26.5 dB gain. So I think that is standard and is all I would ever need for my AVR.

 

[boXem]

Two levels gain setting (boXem stage II buffer only)​

A switch on the rear of the amplifier allows you to set two different levels of gain. Depending on the output capability of your source (pre-amplifier, processor or DAC with volume control) the system gain structure can be optimized for two main targets.
The first is to have the lowest noise, the second the smoothest volume setting as possible.
While the noise levels of modern audio gear has become so low that noise optimization for home audio is often purely academic, having a smooth volume control is something we find so enjoyable that it was our main motivation for integrating the gain control switch.

Can you explain this more? I don't understand what I would be getting and what the dependency is to the output level of the source.

I would be using one with a Denon x8500h AVR if that helps

Edit: I do see 2.6v input sensitivity and 26.5 dB gain. So I think that is standard and is all I would ever need for my AVR.

The basic function of a power amplifier is gain, i.e. output voltage = input voltage x gain.
By changing the gain, one can adapt the amplifier in order to obtain the maximum output voltage (as a consequence the maximum power) according to the capabilities of the upstream component.

As you saw, the standard setting by Hypex is 2.6 V sensitivity and 26.5 dB gain. This means that the amplifier needs 2.6 V at it's input to deliver it's max power into 8 Ohm. 26.5 dB gain means a multiplication factor of 21.13 between the input and the output. Vout = Vin x 21.13.
If you take the x8500h pre out, it is able to deliver a maximum voltage of 2 V. When using the standard gain setting, 2 x 21.13 = 42.27 V RMS.
P = V x V / load = 42.27 x 42.27 / 8 = 223 W. Which is plenty of power, but not the max power that the amp can deliver.

People who would like to be able to reach the max power with a pre delivering 2 V can choose the optional buffer that offers a gain of 28.8 dB.

 

[Acerun]

The basic function of a power amplifier is gain, i.e. output voltage = input voltage x gain.
By changing the gain, one can adapt the amplifier in order to obtain the maximum output voltage (as a consequence the maximum power) according to the capabilities of the upstream component.

As you saw, the standard setting by Hypex is 2.6 V sensitivity and 26.5 dB gain. This means that the amplifier needs 2.6 V at it's input to deliver it's max power into 8 Ohm. 26.5 dB gain means a multiplication factor of 21.13 between the input and the output. Vout = Vin x 21.13.
If you take the x8500h pre out, it is able to deliver a maximum voltage of 2 V. When using the standard gain setting, 2 x 21.13 = 42.27 V RMS.
P = V x V / load = 42.27 x 42.27 / 8 = 223 W. Which is plenty of power, but not the max power that the amp can deliver.

People who would like to be able to reach the max power with a pre delivering 2 V can choose the optional buffer that offers a gain of 28.8 dB.

That's a very nice explanation, thank you very much. I think I can safely say that 223 watts will be enough power for my needs. I very rarely listen over 80db with 86 sensitivity speakers.

 

[HarmonicTHD]

That's a very nice explanation, thank you very much. I think I can safely say that 223 watts will be enough power for my needs. I very rarely listen over 80db with 86 sensitivity speakers.

223W will get you 103.7dB SPL Peaks (assuming 9ft listening distance) so you have more than 20dB headroom for e.g. very dynamic music or movies versus your desired 80dB average listening level. This is good. Plus many bookshelf speaker reach their limit past ca. 96dB, some even earlier (where distortion goes up exponentially).

(Again sorry for that I confused the default settings on that Audiophonics amp and got your hopes up).

 

[makak]

People who would like to be able to reach the max power with a pre delivering 2 V can choose the optional buffer that offers a gain of 28.8 dB.

I’m a little bit confused. The (preliminary) data sheet at https://boxem-audio.eu/en/stereo-amplifiers/42-boxem-a-5517n2.html says:
Gain: 26.5 dB (opt. 20.8 dB by gain switch) and matching Input sensitivity 8 Ohm: 2.6 V (opt. 5V by gain switch), not 28.8 dB.
What gains are possible, when bought with the option “Input and gain stage: boXem stage II (gain switch active)”?

 

[boXem]

I’m a little bit confused. The (preliminary) data sheet at https://boxem-audio.eu/en/stereo-amplifiers/42-boxem-a-5517n2.html says:
Gain: 26.5 dB (opt. 20.8 dB by gain switch) and matching Input sensitivity 8 Ohm: 2.6 V (opt. 5V by gain switch), not 28.8 dB.
What gains are possible, when bought with the option “Input and gain stage: boXem stage II (gain switch active)”?

20.8 and 28.8 dB for a sensitivity of 5 and 2 V in 8R.

 

[Nordling]

About the output connectors: I have the following question: will the hybrid (both Speakon and banana) output be an option in the future? I would like both so I can connect my subwoofers via high level. Also a disadvantage of the Speakon is that the maximum wire size is 4 mm2 or 11 AWG (source).

Not until we have received the final faceplates. For the moment it's an hybrid allowing both speakon and banana connectors.

 

[boXem]

About the output connectors: I have the following question: will the hybrid (both Speakon and banana) output be an option in the future? I would like both so I can connect my subwoofers via high level. Also a disadvantage of the Speakon is that the maximum wire size is 4 mm2 or 11 AWG (source).

There is a bit of physical overlap between the Speakon and banana. For prototyping the Speakon had to endure some trimming, not something we would do on customer units.

 

[Nordling]

I understand, thanks.

 

[Mnyb]

Would your XLR to RCA cable work with this amp ? will it perform ok used this way , or what is the performance penalty for unbalanced input . I undertand that one migth need to opt for the higer gain option to in this case ?

 

[boXem]

Performance: the main issue with RCA is succeptibility to ground loops. Sensing the reference point of the transmitter like our RCA-XLR cables do is indeed an advantage over RCA only cabling.
Gain: if one wants to extract the max power of the amplifier from a 2V out, the high gain is necessary.

 

[boXem]

Just a quick note to mention that the gain/sensitivity values for the optional gain switch were revised on production boards.
The low gain option is now 22.8 dB, allowing a sensitivity of 4 V instead of the previous 5 V. This was done to ensure a better compatibility with the home audio de facto standard of 4 V for balanced outs.

 

[ObjectiveSubjectivist]

Simple yet elegant, I really like new "budget" design.

 

[makak]

My preordered A 5517/N2 should be delivered by tomorrow.
It will replace an old but reliable PA300 from BV Audio, driving a pair of even older infinity Kappa 9.2i Series II (with it’s impedance dip to 1.6 ohm, extended bass switched on ).
I’m looking forward to it.