Eversolo AMP-F2 Class D Power Amplifier (Coming Soon)

[Ze Frog]

Maybe I missed something in between, but I measured the amp some time ago, and it has done well so far in terms of power output. Just go back to page one, and you'll find it.

That's interesting, could there possibly be different SKU's of these?

 

[Karl-Heinz Fink]

That's interesting, could there possibly be different SKU's of these?

Mine came straight from the German distributor—it was the first delivery. The load dependency is typical for designs without the second feedback loop, including the inductor. The second feedback was already mentioned in the original TI literature, but it took years before somebody implemented it. So, as far as I remember, there is a DIY module and now the FOSI Mono - not more. If those survive, we will see more.
When I had the first documents about the chip in my hand, I wondered why TI did not implement it in their evaluation board, and it was just mentioned in an additional paper. Maybe patent issue or perhaps it was not stable? No idea......

 

[daniboun]

Maybe I missed something in between, but I measured the amp some time ago, and it has done well so far in terms of power output. Just go back to page one, and you'll find it.

What is the PSU inside the Eversolo ? 250W RMS (4Ω) 1% THD+N could only be reached with a 48V/10A PSU in the best scenario...

 

[daniboun]

Would be interesting to see one with a modified PSU, wonder if anyone has gone to the trouble...

To be fair to Eversolo it's not their amp design, so hopefully in future they create their own or use something that's more fitting with their own casework. I'd have concerns about this one even if I required lower power output, according to a YouTube review from just 75dB the issues start to be apparent, and that should in theory be under 1W. Going by that and the review here for the amp it's merely a rebadge of and it seems there must be really wild load dependency. It would be really interesting to see an expert tear one down and see where the faults lie just for the technical education side.

The Eversolo is just a single TPA3255 without any PFFB implementation. Get any Aiyima A07 and you have something similar for 7X time cheaper

 

[Karl-Heinz Fink]

What is the PSU inside the Eversolo ? 250W RMS (4Ω) 1% THD+N could only be reached with a 48V/10A PSU in the best scenario...

So, what is your point? I did not open the amp, but I measured it with both channels driven on my AP. Is there any reason NOT to believe the data, or why are you questioning it?

 

[daniboun]

So, what is your point? I did not open the amp, but I measured it with both channels driven on my AP. Is there any reason NOT to believe the data, or why are you questioning it?

That was out of curiousity. I read your measurements -) thx

 

[fotogrofur]

That TPA3255 chip is in so many amps now. Pretty good sound out of my Fosi V3.

 

[Fastnet]

You better don't use 8 Ohm speakers with the amp. It's a bit surprising that Eversolo was happy with the amp as it is. I remember I have seen other TAS 3255 amps here that have been better.
However, the combination with the A6 streamer works pretty well, so you have a modern, easy-to-use set for not too much money.

'Better not to use with 8 Ohm speakers.'
'Surprising Eversolo was happy with the amp.'

For not too much money? This thing costs 799.00 €, that's a good one month salary (1k pay / 800 € take home) for descent jobs in the EU for anyone under 30. Perspective.

Edit: Many thanks for sharing the measurements.

 

[Karl-Heinz Fink]

'Better not to use with 8 Ohm speakers.'
'Surprising Eversolo was happy with the amp.'

For not too much money? This thing costs 799.00 €, that's a good one month salary (1k pay / 800 € take home) for descent jobs in the EU for anyone under 30. Perspective.

Edit: Many thanks for sharing the measurements.

I still believe it's not too much money compared with a lot of other things available on the market. And I don't know where you get your 1k per month thing from. The minimum wage in Germany is 12.x€ per hour, and the average hours per month are 160, so we are more @ 2000€.
The amp works better with 4 Ohm (at high frequencies) but gives full power on both channels driven together. Using the second feedback loop to make the amp less sensitive to the speaker load is tricky. If you are unlucky, the amp starts to oscillate and dies. I think that is what happens with the Fosi amp @ Erin. There is a reason why TI never added this second loop to the initial paperwork, and not many companies have implemented it (yet).

 

[V.b.]

Mine came straight from the German distributor—it was the first delivery. The load dependency is typical for designs without the second feedback loop, including the inductor. The second feedback was already mentioned in the original TI literature, but it took years before somebody implemented it. So, as far as I remember, there is a DIY module and now the FOSI Mono - not more. If those survive, we will see more.
When I had the first documents about the chip in my hand, I wondered why TI did not implement it in their evaluation board, and it was just mentioned in an additional paper. Maybe patent issue or perhaps it was not stable? No idea......

First it was the Topping PA5, now you have available PA5 II and PA7, also Aiyima has the A70 and Audiophonics packages the 3e module in a finished product.

 

[Karl-Heinz Fink]

First it was the Topping PA5, now you have available PA5 II and PA7, also Aiyima has the A70 and Audiophonics packages the 3e module in a finished product.

OK, understood. Let's hope they are all safe. Will get me one and test them.

 

[martin900]

I'm asking myself - what is wrong with the F2? I've seen multiple being listed for sale just after a month or two after original purchase with guys moving back to AB amps.

 

[Audiophonics]

So, what is your point? I did not open the amp, but I measured it with both channels driven on my AP. Is there any reason NOT to believe the data, or why are you questioning it?

We also did a quick measurement of a sample from the 1st batch and found the correct power output.