T3 stereo 300W amplifer board

[tech9_79]

yeah, i talked to cristi about it, its over current protection kickin in on startup. i placed a 10r and a 1r resistor(what i had on hand) on the dc rail and both clicked on fine. been running them for 2 days like this, perhaps after some break in? cuz this is just a temp fix,

Should i be using the powerdown feature to turn the amp on/off? right now i just a have a switch on the Ac lines.

thanks guys,

[NissanSR20Man]

Originally Posted by tech9_79

Should i be using the powerdown feature to turn the amp on/off? right now i just a have a switch on the Ac lines.
thanks guys,

This might be your problem. If you have jumpered out the start up circuit on the SMPS, you might be pushing it into protection when you flick the ac mains on. Wire a basic light switch to the start up (or something that will work) and try to see if it works without the resistors. Meaning, turn on ac power, then turn on SMPS via powerdown feature and then see if it works

[muhkuh86]

I finally finished my first ever diy-amp last weekend. I know it's a while ago when I wrote, that it might take me "two more weeks" to finish the amp, but it took me a lot longer than I had expected

Below you can see some photos. The box without any knobs and switches is the power supply for the amp.







Concerning the sound, I can say that it's OK for me. During the last week I could barely take some time to listen to it, but I can say that it sounds much better than my Yamaha RX-V396RDS and also a little better than my Marantz PM8000 (but only a tiny little bit) especially for the bass.
I don't have anything "high-end" available, which I could compare it with.


The following is a quote from Saarmichel:

Sonically, the Hifimediy-T3S is a disappointment for me. The sound is too technical and unnatural. The Hifimediy-T2 sounds much better.

A Hifimediy T2-amp also costs significantly less than a Hifimediy T3S-amp.

It would be nice if you could describe a little bit more, why you would prefer the T2 instead of the T3S. In the description on the hifimediy website it's said, that the T3S is almost the same as T2 but with a larger output stage. Perhaps I will also order a T2 to hear the difference myself since its not that costly :-)

[platenspeler]

I'm also interested in some more opinions/reviews of the T3s. To me the T3s sounds ok (i built one with a PGA2310 preamp board) but i still prefer the t2 or the irs2092 amps.

Maarten

[nigelwright7557]

Originally Posted by platenspeler

but i still prefer the t2 or the irs2092 amps.

Maarten

The 2092's sound good.
They can be fun to get working for the uninitiated.
It took me a few revisions of pcb before getting it right.
The 2092 is a bit fussy about layout and decoupling.

I eventually came up with a design with buffers to drive irfb4227's and I can get upto a 1000watts out of one.