boXem A 4216/E2 Stereo Amplifier Review

[kyuu]

Not often someone's first post is enough to earn a place on the ignore list...

 

[jcarys]

Reports are coming in of Milton Friedman rolling in his grave rather often lately, and kind of violently. Apparently the neighbors are complaining.

 

[capslock]

Not directly comparable. Specs are taken at different gains (20dB vs 27dB for the 1ET400), hence noise specs will be different.

I wasn't talking about noise, I was talking about harmonics. When they stick this far out of the noise, they are not influenced by the gain setting unless the buffer is of questionable quality.

I don't care about SINAD beyond a certain threshold.

 

[Rja4000]

Thanks for the info. Alas, when I look at the site, I am not sure I see the VAT since my IP address is from US. Should I just add 20% to whatever price I see in Euros?

For Boxem, it says "Tax included" for me.

 

[Oniiz86]

I know that as a seller, my credibility is limited, but people expecting all 1ET6525SA integrations to measure the same are just in the wrong. These modules have such low noise and distortion that the input buffer design has become a lot more critical. As an illustration, the 1ET9040BA has similar performance than the 1ET6525SA. When paired to the reference design buffer, its 5W 4R SINAD is 104 dB while we were able to reach 112 dB with our own buffer design. At same gain obviously.

@boXem Congrats on the wonderful review, I was just wondering is the 104dB figure accurate, that suggests it's no better than the previous 1ET400A reference design buffer which I believe Amir had measured it to be around 104dB at a Gain level of 27.5dB?
I was curious do your amps employ soft-start muting relay circuitry similar to Buckeye Amps?
I noticed Amir had noted it is absolutely silent powering up, that's absolutely fantastic, I wish my 1ET6525SA amps were quiet upon start up but I get a moderate snap, crackle, pop but perhaps that has more to do with my Klipsch RF-7 IIIs but I don't know why as they're only moderately sensitive at 93dB.

 

[RickS]

Some clean up done of off topic posts here and one troll banned. Trolls are best subdued by moderator light - please report them as responding only sustains them!

We have a thread for general tariff discussions and so can discuss non-Boxem stuff there.

Thanks!

 

[boXem]

@boXem Congrats on the wonderful review, I was just wondering is the 104dB figure accurate, that suggests it's no better than the previous 1ET400A reference design buffer which I believe Amir had measured it to be around 104dB at a Gain level of 27.5dB?
I was curious do your amps employ soft-start muting relay circuitry similar to Buckeye Amps?
I noticed Amir had noted it is absolutely silent powering up, that's absolutely fantastic, I wish my 1ET6525SA amps were quiet upon start up but I get a moderate snap, crackle, pop but perhaps that has more to do with my Klipsch RF-7 IIIs but I don't know why as they're only moderately sensitive at 93dB.

The 1et9040ba and 1et6525sa are quiter than the 1et400a, but the 1et9040ba reference buffer is noisier than the 1et400a ref buffer due to the use of opa1656 instead of opa1612, so at the end they perform the same regarding noise.
We do not use muting relays, neither @Buckeye Amps I believe. These modules have a soft start included and pop noise usually come from DC coming from the buffer or the upstream components. We pay a lot of attention to limit the DC produced by the buffer because pops at startup and shutdown are far more real than differences between socketable opamps.

 

[Human1]

Awesome to see. I'm in Canada ordered one July 9 got it by July 20 in my hands.

Got it with the boxem xlr to rca cable (70 euro). Total with shipping was 1,278 euros (43 euros I believe). My credit card charged me 2,138 cad. I think there is 100 or so bucks in conversion there.

I then had to pay 276 cad in taxes when it got here. So not very cheap for Canadians, but cheaper than the NAD stuff at the same power level.

I have the amplifier with kef r3 mets and a wiim ultra. Also using an svs sb 1000 pro. Love the app of the wiim ultra. Also hooked up to my tv which is also hooked up to my pc. Wiim ultra is connected to ethernet.

Note that the xlr to rca cable sold by boxem will not work with the wiim ultra unfortunately. I didn't realize these things have different lengths for the connectors. I'm using cheap amazon xlr to rca and they work fine.

I originally wanted a buckeye but the 25% tarrif and trump nonsense just made a euro amp more viable. The 30 business day build time from Appollon is just ridiculous so it was a hard pass for them. I'd still be waiting.

I can't even see the amp with where it is placed so who cares about looks. Even so I find it looks better in person than the photos and it's pretty small.

The autosense works great. I can hear it click about a minute before the wiim shuts down on in its own.

My biggest gripe? I didn't get a three channel because now I want a center channel.

I was originally thinking of getting a wiim amp ultra but the extra dollars spent are fine as who knows, mabe I will upgrade the speakers one day. I admit a little fomo at play there.

 

[ninja1]

@boXem :
1. Could you be so kind to explain why in your stereo amps you mostly use 1et6525sa (and NCx) vs 7040sa (only as mono /dual mono ?) both in A and Arthur series.
Is it problem with availability, price, power supply...? or 1et6525sa has some benefits (generally or in your implementation) or something else ?

2. I know general opinion about mono / dual mono implementation in amps, but would appreciate to here yours as well . (other than more power, shorter speaker cables...)
So if I am a potentional buyer (and I am), why I should get a pair of monoblocks or dual mono vs stereo ?

Thank you in advance
BR

 

[boXem]

@boXem :
1. Could you be so kind to explain why in your stereo amps you mostly use 1et6525sa (and NCx) vs 7040sa (only as mono /dual mono ?) both in A and Arthur series.
Is it problem with availability, price, power supply...? or 1et6525sa has some benefits (generally or in your implementation) or something else ?

2. I know general opinion about mono / dual mono implementation in amps, but would appreciate to here yours as well . (other than more power, shorter speaker cables...)
So if I am a potentional buyer, why I should get a pair of monoblocks or dual mono vs stereo ?

Thank you in advance
BR

1. the advantage of the 1ET7040SA over the 1ET6525SA is it's ability to deliver a lot of current. To build a stereo amp based on this module, one needs a strong enough power supply. The SMPS3k could make it, but it doesn't fit in the Arthur chassis neither in the A series small chassis. It would be possible with the A series big chassis but from marketing standpoint, it's preferable to have a dual mono setup.
There is also the fact that SMPS3k requires channels to be run out of phase, so a special stereo buffer with connectors compatible with the 1ET7040SA would be needed. For the moment we manage to do all models with only 2 configurable buffer boards, one stereo for 1ET6525SA and NCx500, one mono for 1ET6525SA, 1ET7040SA and NCx500. Making the stereo board 1ET7040SA compatible is technically easy, but it would negatively impact the cost for the "cheap" 1ET6525SA and NCx500, all this for a model that would not sell.
2. a dual mono is literally 2 mono amps in a single box, so power is not impacted. A dual mono amp with bad wiring layout won't perform as well as a mono amp (distortion and channel separation). A dual mono allows the convenience of a stereo amp (single box, single mains cable) and is a bit cheaper than a pair of monos. But needs longer speaker cables.

 

[ninja1]

1. the advantage of the 1ET7040SA over the 1ET6525SA is it's ability to deliver a lot of current. To build a stereo amp based on this module, one needs a strong enough power supply. The SMPS3k could make it, but it doesn't fit in the Arthur chassis neither in the A series small chassis. It would be possible with the A series big chassis but from marketing standpoint, it's preferable to have a dual mono setup.
There is also the fact that SMPS3k requires channels to be run out of phase, so a special stereo buffer with connectors compatible with the 1ET7040SA would be needed. For the moment we manage to do all models with only 2 configurable buffer boards, one stereo for 1ET6525SA and NCx500, one mono for 1ET6525SA, 1ET7040SA and NCx500. Making the stereo board 1ET7040SA compatible is technically easy, but it would negatively impact the cost for the "cheap" 1ET6525SA and NCx500, all this for a model that would not sell.
2. a dual mono is literally 2 mono amps in a single box, so power is not impacted. A dual mono amp with bad wiring layout won't perform as well as a mono amp (distortion and channel separation). A dual mono allows the convenience of a stereo amp (single box, single mains cable) and is a bit cheaper than a pair of monos. But needs longer speaker cables.

Thank you for quick and detailed answer !

 

[daniboun]

2. a dual mono is literally 2 mono amps in a single box, so power is not impacted. A dual mono amp with bad wiring layout won't perform as well as a mono amp (distortion and channel separation). A dual mono allows the convenience of a stereo amp (single box, single mains cable) and is a bit cheaper than a pair of monos. But needs longer speaker cables.

Just to clarify : true dual Mono amp is two 2 mono modules + two dedicated PSU (one per module).

 

[ninja1]

Note that the xlr to rca cable sold by boxem will not work with the wiim ultra unfortunately. I didn't realize these things have different lengths for the connectors. I'm using cheap amazon xlr to rca and they work fine.

Could you please explain...is it on xlr or rca side ? or both ?

EDIT: Obviously the RCA side.....different length ??

Does anyone use boxem rca to XLR with any wiim device ?

 

[boXem]

I would also be curious to have a clearer explanation, never heard such a thing before.

 

[Sokel]

I would also be curious to have a clearer explanation, never heard such a thing before.

Probably because Wiim's connectors are recessed and there's no room for them on the outer side.
If I got it right.

 

[boXem]

Probably because Wiim's connectors are recessed and there's no room for them on the outer side.
If I got it right.

Oh, you are probably right. Never paid attention to this.

 

[ninja1]

I have several rca cables, including one(or two) with Neutrik connectors and they all fit to wiim pro plus...Maybe Wiim Ultra is different...

 

[kyuu]

I have several rca cables, including one(or two) with Neutrik connectors and they all fit to wiim pro plus...Maybe Wiim Ultra is different...

Wiim Pro Plus:

Wiim Ultra:

The Pro Plus has an oval cutout that encompasses both RCA jacks, whereas the Ultra has an individual round cutout for each RCA jack. Not sure if that would affect the fit of these particular Neutrik RCAs, but it seems like both would have issues. For reference, these are the particular Neutrik RCAs we're talking about:

I haven't used cables with these terminations before, but I believe the way it works is that, when fully seated, the shield/ground will be retracted into the body of the connector. This means that if the body is too large in diameter, it won't fit into the recesses for the RCA jacks. It's a nice connector, but quite likely Wiim didn't take it into account when designing the recessed connections since that's not how 99.99% of RCA terminations work.

 

[poopy]

Wiim Pro Plus:

View attachment 470968

Wiim Ultra:

View attachment 470969

The Pro Plus has an oval cutout that encompasses both RCA jacks, whereas the Ultra has an individual round cutout for each RCA jack. Not sure if that would affect the fit of these particular Neutrik RCAs, but it seems like both would have issues. For reference, these are the particular Neutrik RCAs we're talking about:

View attachment 470970
I haven't used cables with these terminations before, but I believe the way it works is that, when fully seated, the shield/ground will be retracted into the body of the connector. This means that if the body is too large in diameter, it won't fit into the recesses for the RCA jacks. It's a nice connector, but quite likely Wiim didn't take it into account when designing the recessed connections since that's not how 99.99% of RCA terminations work.

Looks like TV aerial type

 

[SKNG]

Wiim Pro Plus:

View attachment 470968

Wiim Ultra:

View attachment 470969

The Pro Plus has an oval cutout that encompasses both RCA jacks, whereas the Ultra has an individual round cutout for each RCA jack. Not sure if that would affect the fit of these particular Neutrik RCAs, but it seems like both would have issues. For reference, these are the particular Neutrik RCAs we're talking about:

View attachment 470970
I haven't used cables with these terminations before, but I believe the way it works is that, when fully seated, the shield/ground will be retracted into the body of the connector. This means that if the body is too large in diameter, it won't fit into the recesses for the RCA jacks. It's a nice connector, but quite likely Wiim didn't take it into account when designing the recessed connections since that's not how 99.99% of RCA terminations work.

I'm using RCA to XLR cable from the WiiM Ultra to power amp(from another maker to be clear) with this particular RCA connector, same Neutrik XLR connector on the other end without any issues.