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BOXEM Audio | Arthur 4215/E2 Purifi Amplifier | Owners' Thread

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groovybassist

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ComasSky

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I have pop on start and shutdown of my Audiophonics HPA ET400, there is some pop on boxem ?
 

Bobesku

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What would be the best way to connect this amp with a Topping E50 DAC? RCA -> XLR or TRS -> XLR? (good/recommended cables will be used)


Topping E50 specs extract below:



MEASUREMENTS @ USB, 96KHZ
THD+N @ A-WeightingSingle-ended: < 0.0001% @ 1kHz
Balanced : < 0.00009% @ 1kHz
THD @ No-Weighting 90kBwSingle-ended: < 0.0003% @ 20Hz-20kHz
Balanced : < 0.0003% @ 20Hz-20kHz
SNR @ A-WeightingSingle-ended : 124dB @ 1kHz
Balanced : 126dB @ 1kHz
Dynamic range @ A-WeightingSingle-ended : 124dB @ 1kHz
Balanced : 126dB @ 1kHz
Frequency responseSingle-ended : 20Hz-40kHz (±0.3dB)
Balanced : 20Hz-40kHz (±0.3dB)
Output levelSingle-ended : 2Vrms @ 0dBFS
Balanced : 4Vrms @ 0dBFS
Noise @ A-WeightingSingle-ended : < 1.3µVrms
Balanced : < 2.3µVrms
CrosstalkSingle-ended : -130dB @ 1kHz
Balanced : -139dB @ 1kHz
Output impedanceSingle-ended : 20Ω
Balanced : 100Ω
 

boXem

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What would be the best way to connect this amp with a Topping E50 DAC? RCA -> XLR or TRS -> XLR? (good/recommended cables will be used)


Topping E50 specs extract below:



MEASUREMENTS @ USB, 96KHZ
THD+N @ A-WeightingSingle-ended: < 0.0001% @ 1kHz
Balanced : < 0.00009% @ 1kHz
THD @ No-Weighting 90kBwSingle-ended: < 0.0003% @ 20Hz-20kHz
Balanced : < 0.0003% @ 20Hz-20kHz
SNR @ A-WeightingSingle-ended : 124dB @ 1kHz
Balanced : 126dB @ 1kHz
Dynamic range @ A-WeightingSingle-ended : 124dB @ 1kHz
Balanced : 126dB @ 1kHz
Frequency responseSingle-ended : 20Hz-40kHz (±0.3dB)
Balanced : 20Hz-40kHz (±0.3dB)
Output levelSingle-ended : 2Vrms @ 0dBFS
Balanced : 4Vrms @ 0dBFS
Noise @ A-WeightingSingle-ended : < 1.3µVrms
Balanced : < 2.3µVrms
CrosstalkSingle-ended : -130dB @ 1kHz
Balanced : -139dB @ 1kHz
Output impedanceSingle-ended : 20Ω
Balanced : 100Ω
TRS, no doubt.
 

boXem

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@boXem Is there a relay and a soft start during startup and shutdown ?
Soft start is done by the module itself. Effect is a slight "click" at startup and a completely silent shutdown.
Noisy startup and shutdown are created by a relatively important DC voltage at the output. Since the modules outputs are themselves almost DC free, DC comes from the input buffer or/and upstream components. A relay won't do anything against this.
For the 4215 we paid attention not to create DC with the input module. That is one of the advantages of the OPA1656. In the 4222/E1 the buffer is AC coupled to the module, so that even DC from the outside world is filtered.
 

ComasSky

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Soft start is done by the module itself. Effect is a slight "click" at startup and a completely silent shutdown.
Noisy startup and shutdown are created by a relatively important DC voltage at the output. Since the modules outputs are themselves almost DC free, DC comes from the input buffer or/and upstream components. A relay won't do anything against this.
For the 4215 we paid attention not to create DC with the input module. That is one of the advantages of the OPA1656. In the 4222/E1 the buffer is AC coupled to the module, so that even DC from the outside world is filtered.
Thanks for the answers!

Let's just say that I want to avoid this kind of problem (at the end, I turn the amp on and off, and we hear the big pop).

 

boXem

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Thanks for the answers!

Let's just say that I want to avoid this kind of problem (at the end, I turn the amp on and off, and we hear the big pop).

If the source is the amplifier, it's not a boXem. This is one of the tests we perform before packing the amp.
 

ComasSky

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If the source is the amplifier, it's not a boXem. This is one of the tests we perform before packing the amp.
In this case, it's a Atoll ST300 + Audiophonics.
The pop is present even without a source at switch-on / switch-off.
This was to show you an example of the pop that Audiophonics makes at startup/shutdown and that I try not to have with the next amp.
 

daniboun

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Thanks for the answers!

Let's just say that I want to avoid this kind of problem (at the end, I turn the amp on and off, and we hear the big pop).


Yeah I see an Atlantis Labs AT23 speaker, right ? La classe mec ))
If I were you, I would send back the Audiophonics to warranty
 

daniboun

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Haha yes AT23 (Coucou de Bordeaux ! ).
I will send back the amp

Nice (I am from Lyon). Enjoy your system) and take a look at my threads, you will find some very nice discoveries)
 

Sokel

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Thanks for the answers!

Let's just say that I want to avoid this kind of problem (at the end, I turn the amp on and off, and we hear the big pop).

That sounds like a bad source to me.
If you on and off the amp with nothing connected to it except the speakers does the same?
 

csup

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I've been using a Boxem 4215/E2 for a little over 6 months and it has been flawless. It runs cool, the auto on/off feature works well, doesn't take up a lot of space, and it sounds great. Visually it's not an eye-catching centerpiece, but it does its job so well that it doesn't need to be ostentatious.

photo_2023-11-26_10-51-06.jpg
 
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