3e audio A7/A7 Mono Amplifier Review

[Guddu]

Got it. Thank you so much.

So if I want to use these with Philharmonic Audio BMR monitors, which dip to 3.5 ohms a bit, I should stick with the A7.

The A7 stereo will have half the output of the mono right?

For about 4 ohm speakers, A7 SE is the best value you get for the money.
But A7 is the safe bet, not just for your current speaker but perhaps for the next one which might dip even lower.

 

[Alannn]

...Or even no volume control as far as I'm concerned. ...

That would severely limit the device's use as a desktop amp, and also for many hi-fi systems. It would make such a device significantly more expensive and perhaps even unsustainable for the manufacturer.

What would be the difference if you turned the volume control all the way up? And what would be the advantage?

There would be no difference in sound, and the disadvantage would be the loss of the ability to limit the maximum volume, for example, when using it with a DAC, or to adjust it for an AVR or other devices.

Right now 3e gives us the versatility of volume knob and it's defeat option. Many of us use the defeat setting all the time, so volume knob is the extra expense.

Using as a desktop amp, you obviously prefer reaching for a knob instead of using your mouse to control volume. Your choice. I happen to be an ardent volume knob fan in my car, btw.

But on the topic of limit to maximum volume, I use a digital setting on my Wiim app which is less vulnerable to getting accidently nudged than a physical knob on a desk which has other movable objects on lt.

 

[Roland68]

Got it. Thank you so much.

So if I want to use these with Philharmonic Audio BMR monitors, which dip to 3.5 ohms a bit, I should stick with the A7.

The A7 stereo will have half the output of the mono right?

I would prefer the A7.

The A7 has the same performance as two A7 Mono units.
Or, two half-units make one whole unit: 2 x A7 Mono = A7.

 

[Mort]

Is it worth paying for a better power adapter for the A7? On us Amazon there are only third party options. No 3e model in 10A.

 

[monsterlag]

No issues so far, happy with what I got, two 48 V 5 A gaN bricks are doing a good job. As I mentioned, started my AB comparison sessions but will have to wait for the next weekend to do a more proper one, i.e. level match with REW/Umik-1, and with selected DSD, HR PCM tracks etc.

So far has only done it in Mono, heard no difference whatsoever.

View attachment 503607

I am running my BMR Monitors with the A7 and 48v 10a PSU( you can see the small box next to the Center BMR) and haven’t noticed any issues. It can raise the volume to hearing damaging levels with no issues.

 

[Mort]

I am running my BMR Monitors

Are those the new cherry burl? I didn't like the stock photos but they look good!

Where did you order the 10A PS?

 

[peng]

Are those the new cherry burl? I didn't like the stock photos but they look good!

Where did you order the 10A PS?

amazon https://www.amazon.com/AIYIMA-Suppl...20a+aiyima+power+supply,industrial,142&sr=1-1

 

[ziggurcat]

Are those the new cherry burl? I didn't like the stock photos but they look good!

Where did you order the 10A PS?

AliExpress is another place you can order the 10A PSU. Go to the 3e Audio store there, and select the "Color" that is the PSU on its own for your region.

https://www.aliexpress.com/item/1005007964184254.html

 

[Mort]

AliExpress is another place you can order the 10A PSU. Go to the 3e Audio store there, and select the "Color" that is the PSU on its own for your region.

https://www.aliexpress.com/item/1005007964184254.html

Thanks. I see it now on Amazon. I think it just came back in stock.

A7 Stereo and 48v/10a power supply together are $335 before tax.

 

[harkpabst]

The A7 SE is rated for 4 ohm load so it can handle thise dips. Just about any 4 ohm nominal speakers will have dips below 4 ohms. The BMR’s impedance is not the issue, but the sensitivity is a bit low for sure. Get the 10 A brick that will help.

I generally agree, but impedance dips down to 2.9 or even 2.5 ohm are not acceptable for a 4 ohm rating. IEC 60268-5 and EIA/RS-299-A require the actual minimum impedance to be no lower than 0.8 times the nominal impedance.

I'm not pointing at Dennis Murphy, not at all. But I do recommend to rather go with the 3E AUDIO A7 in favor of the A7se in this case.

 

[Mort]

I generally agree, but impedance dips down to 2.9 or even 2.5 ohm are not acceptable for a 4 ohm rating. IEC 60268-5 and EIA/RS-299-A require the actual minimum impedance to be no lower than 0.8 times the nominal impedance.

I'm not pointing at Dennis Murphy, not at all. But I do recommend to rather go with the 3E AUDIO A7 in favor of the A7se in this case.

I think with the new driver, sensitivity is higher but the impedance dips lower. @peng may have been using Erin's data which is the older driver.

 

[harkpabst]

Higher sensitivity cannot compensate for a higher output impedance of the amplifier, though. I would still go with the A7 (and personally love the A5, which I did not compare to any other 3E AUDIO product).

 

[Mort]

Higher sensitivity cannot compensate for a higher output impedance of the amplifier, though. I would still go with the A7 (and personally love the A5, which I did not compare to any other 3E AUDIO product).

Didn't mean to imply that. Was just reiterating the differences. Yeah A7 stereo is the way to go.

 

[harkpabst]

Didn't mean to imply that.

Even if you did, you're free to contradict my opinion. No matter what, there's always someone more knowledgeable, and I'm well aware of that.

 

[monsterlag]

Are those the new cherry burl? I didn't like the stock photos but they look good!

Where did you order the 10A PS?

Yup, it’s the new Red Burl so technically I guess it’s the BMR V2.5

 

[peng]

I generally agree, but impedance dips down to 2.9 or even 2.5 ohm are not acceptable for a 4 ohm rating. IEC 60268-5 and EIA/RS-299-A require the actual minimum impedance to be no lower than 0.8 times the nominal impedance.

I'm not pointing at Dennis Murphy, not at all. But I do recommend to rather go with the 3E AUDIO A7 in favor of the A7se in this case.

I would agree but in this case, Mort said the 2.5 ohm dip was at 1220 Hz. I am not much concern about a dip at such relatively high frequency. I also think the A7 is better for Mort, and in fact I suggested that he gets the 10 A power supply for little more margin, than the 5 A one.

 

[peng]

I think with the new driver, sensitivity is higher but the impedance dips lower. @peng may have been using Erin's data which is the older driver.

I did read the Stereophile review so I know the new version is more demanding but the 2.5 ohm dip is at above 1 kHz, so I am less concerned, though still recommend the 10 A power supply for your use case. B

By the way, the original BMR also supposed to have 86 dB/2.83 V, but it feels more like 83 dB. As you know the minidsp flext Htx is limited to just a little more than 4 V max., that's more than enough, but because I use it with DLBC, that apparently grab 10 dB for reserve, so I have to listen at moderately loud SPL with volume at -6, and feel like to crank it up to 0, not really an issue but don't feel comfortable, psychologically speaking lol.. I am now tempted to use use a preamp with the HTx or with a desktop DAC, just to feel better...

 

[harkpabst]

I would agree but in this case, Mort said the 2.5 ohm dip was at 1220 Hz. I am much concern about a dip at such relatively high frequency. I also think the A7 is better for Mort, and in fact I suggested that he gets the 10 A power supply for little more margin, than the 5 A one.

At 1220 Hz I wouldn't be concerned about the power or current demand either. But I'd like to make sure that the amp's output impedance is as low as possible and that would lead me to the A7 or the A5, if the power output is sufficient.

 

[antcollinet]

I generally agree, but impedance dips down to 2.9 or even 2.5 ohm are not acceptable for a 4 ohm rating. IEC 60268-5 and EIA/RS-299-A require the actual minimum impedance to be no lower than 0.8 times the nominal impedance.

I'm not pointing at Dennis Murphy, not at all. But I do recommend to rather go with the 3E AUDIO A7 in favor of the A7se in this case.

Possibly - we don't have measurements, but since the A5 can happily drive 2ohm loads, I'd be surprised if the A7SE couldn't also:

 

[SnakeLord]

Possibly - we don't have measurements, but since the A5 can happily drive 2ohm loads, I'd be surprised if the A7SE couldn't also:

View attachment 503703

Both A5 and A7 are utilizing their double chips design in the PTBL configuration allowing them to drive much lover impedance.
A7/A5SE are mono single chip designs and wont dip that deep.