3e audio A7/A7 Mono Amplifier Review

[somebodyelse]

Probably the 10A PSU can also. 10A is a continuous rating. It will almost certainly be capable of higher transient peaks - even for some time.

Didn't someone track down the datasheet for it? Without that it's speculation what it'll do with transient overload - some will trigger over-current protection. Even within MeanWell models we see significant differences in short term overload behaviour.

 

[Ruediger]

GAN is not a quality indicator. You can get nasty gan power supplies just as you can nasty power stages with conventional power switches. Gan just buys you higher efficiency and/or smaller size.

Just get make sure the PSU is a quality device from a reputable supplier - whether GAN or not.

Yes, I wouldn't wonder if there are also offers for terrible GaN psu for these specs.

The ones mentioned are known to be good.

At work we recently renovated our "juicer station" - 18 x USB-C PD 100w - to GaN bricks. The reduced heat alone .. and half the size. If there is a choice and it has no other drawbacks, GaN is currently the thing for (high) power bricks.

 

[antcollinet]

Without that it's speculation

I agree - hence "almost".

 

[Pulkass]

So I finally order both fosi za3 and e3 A7 yesterday and did some good listening session.

One thing for sure the za3 plays definitly louder… to hit 90dB with A7 i had to put preamp at 90% volume while za3 preamp volume was at 70% for same dB

Yes absolutely. I have both too. And the Fosi audio is much louder

 

[Ruediger]

Yes absolutely. I have both too. And the Fosi audio is much louder

Gain levels would need to be matched.

If you read the review, it talks about the rather high gain. Just 1.2v to reach clipping. The A7 has "normal" gains from xlr low with opamp bypass to rca low and high. I guess even opamp high is below what the Fosi does.

Is it a feature? Personally I want the gain where it produces better sinad. Not turn the preamp down and have the amp produce a lot of gain on a "weak" signal. That's why I would prefer the 3 proper gain options of the A7. Needless to say these amps are in different price classes.

 

[Bernard23]

Forgive me for possibly repeating a question already asked, but I read the first 10 and last 8 or so pages and didn't see the answer to the question:
Are the 48V 5A PSUs adequate for the mono amp? That's what is bundled on Amazon UK right now. Or would I benefit from getting a 10A unit for each amp?
I regularly listen at 80+dB SPL at the mlp via Linton Heritage boxes. I do have a couple of BK subs that handle things below 60Hz so in truth my yamaha a-s501 is likely more than adequate but I want smaller form and a simpler setup. It's also possible that I might not keep the subs forever as we're rearranging our domestic spaces!

 

[LambdaCDM]

regularly listen at 80+dB SPL at the mlp via Linton Heritage boxes.

Sensitivity 90db, 6ohm. So 48v 5a is enough.

 

[Bernard23]

Sensitivity 90db, 6ohm. So 48v 5a is enough.

Linton's measured below that, at least Erin did, more like 87 IIRC

 

[Bernard23]

The difference in PSUs is just a math problem. These class D amps with switching power bricks are pretty clean right up until they run out of power.

Here is the napkin math in my room:
87 dB/2.83V is the 1 meter sensitvity of F206 speakers
- 3 dB to convert 2.83V to 1 watt for 4 ohm speakers
+ 3 dB for two speakers (both channels driven)
- 9 dB because I listen at 2.5 - 3.0 meters
= 78 dB at my listening position with 1 watt per channel

Amir tested the e3 A5 with 38V5A PSU to reach 92 watts x 2 channels. log10(92 watts) x 10 dB/bel = 19.6 dB. An e3 A5 can reach 78 + 19 dB = 97 dB in my room.

In this review Amir tested an A7 mono with 52V9A PSU (468 watts) to reach 208 watts. log10(208) x 10 =23.2 dB. 78 + 23 =101 dB in my room.

A 48V5A PSU comes right in between at around 99dB in my room. For music with 14 dB dynamic range, I can play at 85 dB. I live in an apartment so reality is much below this.

So, in my case, where the Lintons drop to below 4 ohm, and I frequently listen at 85dB sometimes higher the 10A brick would be a reasonable headroom insurance; though I'm going to use 2 x mono which will have their own 5A brick, plus subs already have their own 400W amps each. I guess I'll find out when I get them and try to launch my speakers into space.

 

[john61ct]

In the exact right confluence of factors the larger ampacity CAN make an audible difference.

Personally in that case I would buy an amp with more headroom, designed to put out a higher clean power level

 

[Ruediger]

With these amps I would always get the 48v 10a psu (where 48v is applicable). Just for the versatility of it.

The specs list several output power ratings beyond the 48v 5a psu capability for the A7 mono. I know the match does not have to be exact there, but personally I would not pair a psu under the amps capability. In reality though it is probably no difference for 99% of the users.

 

[Bernard23]

Logically, given one 10A brick drives the stereo amp, so 2 x 5A bricks for 2 x mono compares given the architecture of the stereo amp?

 

[john61ct]

It can be hard to find trustworthy 10A listings under $80 delivered.

Whereas the 5A ones might only add $15 to tge no-PSU price.

 

[john61ct]

Please post suggested models / sources here

PSUs for TPA3255 amps when max power desired

Please post purchase links to reasonably priced units, for non-US sources, specify whether US tariffs are an issue. Context: https://www.audiosciencereview.com/forum/index.php?threads/ampapa-d1-stereo-amplifier-review.69682/post-2533335 If you have constructive feedback on the back & forth...

www.audiosciencereview.com

Since that dedicated thread is useful to all standalone amps using these TPA3255 not just 3e

 

[Bernard23]

It can be hard to find trustworthy 10A listings under $80 delivered.

Whereas the 5A ones might only add $15 to tge no-PSU price.

The ones I've bought come with the psu included, £300 for the pair delivered.

 

[Ruediger]

Please post suggested models / sources here

PSUs for TPA3255 amps when max power desired

Please post purchase links to reasonably priced units, for non-US sources, specify whether US tariffs are an issue. Context: https://www.audiosciencereview.com/forum/index.php?threads/ampapa-d1-stereo-amplifier-review.69682/post-2533335 If you have constructive feedback on the back & forth...

www.audiosciencereview.com

Since that dedicated thread is useful to all standalone amps using these TPA3255 not just 3e

Added an entry there for the 48v 10a GaN psu I got from audiophonics.

But I think it is already known from Aiyima and is the same that is available around $80 from Ali, amazon, ..

The very low cost for the bundled 48v 5a psu is a real argument though.

 

[LambdaCDM]

Linton's measured below that, at least Erin did, more like 87 IIRC

It's not critical. What is you room dimensions? How far from speakers your listening position?

 

[Bernard23]

8m x 5m

3m

I already looked at the online room power calcs. Taken as a rough estimate 2 x 150W gets me 105dB at 3m so the 5A PSU is fine.

 

[LambdaCDM]

8m x 5m

3m

I already looked at the online room power calcs. Taken as a rough estimate 2 x 150W gets me 105dB at 3m so the 5A PSU is fine.

105dB it's too loud in my opinion, even peak. Some calculation from google at 85db Continuous and 100db peak at your room and sweet spot.. So yes, if you like so much SPL, then 10A per/amp PSU will be better in some cases.

 

[Bernard23]

105dB it's too loud in my opinion, even peak. Some calculation from google at 85db Continuous and 100db peak at your room and sweet spot.. So yes, if you like so much SPL, then 10A per/amp PSU will be better in some cases.

Assuming a 90% efficiency of each monoblack, the 5A PSU will yield 214W. That exceeds the max power handling spec of the Lintons, but given they're not doing anything below 65Hz (or whatever crossover f I set) then there's even less need for that much power. As much as I like SPL, I'm not about to start venturing above 100dB for any length of time. The assumption here in the calculation is that mine is a "typical listening room"

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