3e audio A7/A7 Mono Amplifier Review

[john61ct]

using a measurement microphone positioned precisely at ear level and at a consistent distance.

Yes, thanks and my question is, is it possible to get a reasonably accurate result from UMIK-2 without using a full blown PC, just a reco app on an Android?

 

[Roland68]

Yes, thanks and my question is, is it possible to get a reasonably accurate result from UMIK-2 without using a full blown PC, just a reco app on an Android?

The UMIK-2 is a self-contained system that converts the analog measurement signal into a digital result via an ADC, completely independently of the device being used.
The only factor to consider is the application of the calibration file, but that simply ensures the linearity of the frequency response, not the repeatability of the measurement accuracy.

 

[john61ct]

Yes, but it does require a host + software to display the measurements and store the resulting history, correct?

That can be done with Android, amirite?

I'm asking for app reco's, from anyone here.

 

[Bernard23]

Yes, thanks and my question is, is it possible to get a reasonably accurate result from UMIK-2 without using a full blown PC, just a reco app on an Android?

Yes.
I use Spectroid app and a Dayton mic.

My room EQ process as follows

Wiim roomfit using Android phone and Dayton mic (I use the B&K target)

Low frequency sweeps (Spotify test tracks) with Spectroid app and Dayton mic -> add a manual PEQ profile to flatten any remaining lumps. Rerun the test and adjust loop until you've got it within a couple of dB or so. Then add filters to taste - I add a high shelf to mitigate old ears HF losses

 

[john61ct]

Thanks but, I'm sorry I failed to repeat that I'm only looking to do full spectrum SPL metering, not RTA EQ / DSP related stuff.

For that I'll use a PC with REW and properly interfaced XLR calibrated mic.

And apparently Spectroid doesn't even support mic calibration files ?

 

[Bernard23]

Thanks but, I'm sorry I failed to repeat that I'm only looking to do full spectrum SPL metering, not RTA EQ / DSP related stuff.

For that I'll use a PC with REW and properly interfaced XLR calibrated mic.

And apparently Spectroid doesn't even support mic calibration files ?

Ah OK.

No it doesn't but I'm suspicious of the cal files anyway so haven't bothered. I use room fit and Spectroid as semi quantitative methods anyway. Given it's not a laboratory experiment then knowing the measurement uncertainty isn't important in this case (Amirs words not mine from different thread!)

 

[john61ct]

I trust most sellers wrt calibration files.

Some only do on-axis 0°, but UMIK gets two, Sonarworks SoundID gets three.

Cross-Spectrum Labs is probably the best stateside, at least national mass market.

There are local calibrators as well, usualky at least $60 though

 

[Ruediger]

Re. different feet for the A7.

When stacking them a bit more distance than the little rubbers is desirable. Had these 30mm alu speaker feet lying around. This is the small variant, two sizes are available. They simply go over the rubbers as their inner diameter = rubber outer diameter. Or could go on with extra 3m tape.

DolDer Aluminium Device Feet HiFi Absorber, 4 Pieces, 30 x 23 mm, Black | High stability, rubber damper, speaker shock absorber feet: Amazon.de: Electronics & Photo

DolDer Aluminium Device Feet HiFi Absorber, 4 Pieces, 30 x 23 mm, Black | High stability, rubber damper, speaker shock absorber feet: Amazon.de: Electronics & Photo

www.amazon.de

 

[CptKaos]

I cut up one of those inexpensive Mini Media Stands and added 120mm PC case fans to make coolers for my A7's

 

[LambdaCDM]

Re. different feet for the A7.

Looks nice, so just ordered the same on AliExpress for 10$. Right now, I’m using clear silicone feet, which doesn't look all that attractive.

Mini Media Stands and added 120mm PC case fans

Doubtfull... But ok. This is because a mono unit runs cooler than a stereo one, whose heatsink heats up to 55°C. Consequently, active cooling seems unnecessary. Moreover, a fan creates unwanted noise and draws dust into the chassis.

 

[john61ct]

The Mono can go up to 51V PSU, so while shooting for max output the cooler design (better heat dissipation?) is likely needed.

 

[CptKaos]

Looks nice, so just ordered the same on AliExpress for 10$. Right now, I’m using clear silicone feet, which doesn't look all that attractive.


Doubtfull... But ok. This is because a mono unit runs cooler than a stereo one, whose heatsink heats up to 55°C. Consequently, active cooling seems unnecessary. Moreover, a fan creates unwanted noise and draws dust into the chassis.

hahaha, then dont

 

[Shotgun Rico]

I put some isolation feet I had lying around to get some air under my A7 stereo.

 

[Bleib]

I use Aliexpress silicone-feet, it raises it up quite a bit more than the default. Mine are a bit deeper in, so they are very hard to see

 

[LambdaCDM]

Right now, I’m using clear silicone feet, which doesn't look all that attractive.

hahaha, then dont

Doesn't the fan noise bother you?

 

[maxchau]

Agreed. There are theoretical benefits of a GaN FET over a MOSFET, that's just the physics. How it is implemented is critical, it's an entirely new technology. Is it worth it for consumer audio? Who knows, probably if you're a manufacturer because placebo sells. There would likely be measurable differences, but are they audible? Personally I like the idea of 500+W in a box that isn't the size of a small fridge and weighs 100kg.

In this case, I suggest check out Icepower 1200AS2, and use 2 of them for dual mono, which I have been listening to. They sound phenomenal, especially on large speakers. 1200AS2 has total control over every speakers I have not experienced before. I also own 3E 480-1-129 and 260-2-29 amps in dual mono configurations. My point is Class D amps will benefit greatly with dual mono setup, which out perform stereo amp noticeably in every regards.

 

[Ruediger]

Doesn't the fan noise bother you?

I guess a fan could be tuned to be barely noticeable. But I would not want the use one with this amp either. The case of the A7 is designed for air convection. The openings are too big to use a fan, even at very low rpm. Stuff will get in there. Not all of it tiny dust. Depends on the household if that is a topic. I have wool carpets and cats. They smile at me while I write this. Very suspicious.

 

[CptKaos]

View attachment 542088




Doesn't the fan noise bother you?

no, they are Arctic Bionix case fans with variable speed controllers, virtually silent at the RPM's I have them set to run

 

[metal4ever]

Hey! If I purchase dual 3e A7 mono amps will the RCA connection indicate RED for right amp and WHITE for the left amp? Or will both amps have the RED . I just figured if you purchase dual, one amp will have a red RCA and the other will have a white RCA.

 

[CptKaos]

Hey! If I purchase dual 3e A7 mono amps will the RCA connection indicate RED for right amp and WHITE for the left amp? Or will both amps have the RED . I just figured if you purchase dual, one amp will have a red RCA and the other will have a white RCA.

all of the LED's are red, there is no specific left or right amp