I tried the eBay MX50 DIY Kit, Class AB 100W+100W; Worked but problem

[denbret]

a link please,i want try this version

I also ordered a pair of the latest version 2021.

Here is the seller's link, more than once I buy from him. Good communication and service.

MX50X2 2021

 

[denbret]

I received my MX50X2 2021.

 

[odisy]

Waiting for sound quality feedback..

 

[nigelwright7557]

What a terrible design and missing decoupling too !

That is typical of the lottery when you buy Chinese items.

 

[ljm_ljm]

What a terrible design and missing decoupling too !

That is typical of the lottery when you buy Chinese items.

ha-ha. Many years have passed. I see you are still so healthy and have a temper
I recommend eating more vegetarian food.

 

[Hennady Kovalsky]

a-ha. Many years have passed.

How many implementations of amplifiers I see, many shunt electrolytes on the board in such a way as to reduce the influence of parasitic inductance. Can these capacitors be immediately provided on the printed circuit board?

 

[ljm_ljm]

How many implementations of amplifiers I see, many shunt electrolytes on the board in such a way as to reduce the influence of parasitic inductance. Can these capacitors be immediately provided on the printed circuit board?

I don't think it's useful. The biggest significance of this is that the psychological feeling is more comfortable.
But it doesn't do any harm.
If you like it. No problem.

 

[Hennady Kovalsky]

The biggest significance of this is that the psychological feeling is more comfortable.

Yes, you are right when you see low-quality blocking capacitors that work with difficulty at frequencies near the unity gain frequency of several megahertz, indeed, "to calm the soul" you have to solder film capacitors.

But it doesn't do any harm.
If you like it. No problem.

Seriously, this is a problem - the power supply voltage wires of the amplifier with a length of more than 12 cm already have significant inductance, because. + and - are connected in series, the inductance increases, it also increases in your board design due to the far spacing of the input + and - on the board, no more than 1.5 cm is allowed, you have more than 6 cm .... That is, the closer the conductors go + and - on the board, the less inductance, you have them on the board with the letter O, so shunting with film capacitors is mandatory.

P.S. I would really like you to improve the quality of your products, then a higher quality will be available to radio amateurs all over the world. If you do not need it, then I am not an assistant ...

 

[odisy]

In my 35 yrs of diy amplifier-preamplifier journey,mx50x2 with some minor mods is the best sounding amplifier i ever made,i think beats every comercial one.The mods its not that proposed from Mr Henandy.Cheers!

 

[odisy]

The soundstage & 3d sound of this amplifier is enormous,maybe the couse is that every power transistor has his own driver! Also the bass is superb..

 

[Hennady Kovalsky]

The mods its not that proposed from Mr Henandy.Cheers!

it's like in the movie "don't look up"
so do not look at the top - it will be ok....

 

[Hennady Kovalsky]

Also the bass is superb..

what Bias current of output transistors is used?

 

[odisy]

16ma per transistor..for mx50x2..

 

[odisy]

also the ljm dac is superb with big clear sound..enjoy the sound of the combination..

 

[Hennady Kovalsky]

16ma per transistor..for mx50x2..

I think it's a small current, but if you like it, then ok

also the ljm dac is superb with big clear sound..enjoy the sound of the combination..

Thanks, I use Electrocompaniet ECM-2

 

[GT40]

This is an updated version of mx50x2 2021 design update.
Four ST - 2sc5200 are used. The price is lower. Better performance.

Just ordered these 2021 diy boards, may be possible to have the schematic ?

 

[odisy]

Just ordered these 2021 diy boards, may be possible to have the schematic ?

Pls give a feedback how it sounds.

 

[odisy]

I try the new version of mx50x2 ,superb sound ,just need minor modifications.Replace the C11 (10uf electrolytic) with 1uf MLCC (multilayer) like the old version and need a trimmer pot for biassing current at 15ma per output transistor...

 

[denbret]

I mounted the new MX50X2 in a case.

No hissing even very close to the tweeters. Listen only on test bench .

I finish properly and will test more advanced listening on my new Wavecor "Lambic V3" bookshelf (6" 4 ohm woofer and 1.25" tweeter, fc 1.5khz).

The ultimate test will be on my main speakers, the Focal Chora 826.

 

[odisy]

It's better than previous version,lower distortion,more punch & can drive everything.i change all the electrolytics on the board.