Hey,

It costed me 50 dollars per board. And you can have two channel from one board. So including PSU and Tranny, the total cost of the amp was about 100 bucks. I think it is really good way to try out SMD stuffs. The bad part is that everything is SMD. So you better have some SMD resistors and caps lying around, because you gotta change some values to get it working as headphone amp.

T

630 parts....

Guy's you must read more carefully! All transistors are doubled or even tripled! In all places I have made room for TO-92 types and SOT23. The input stage has even room for SOT363, these tiny matched transistors.

Not 630 parts! but not few.....

Those of you who wonders, I have made two discrete opamps. The first is a preamp and the second one is the correction amp.

The preamp has parallel connected input transistors in order to get low noise with cheap transistors. You can also use MAT02/03 and even get those in parallel in order to ger ultra low noise.

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Okay, sorry, I just checked the # of items in the excell spreadsheet, I didn't realize you put alternate parts there too. Just how many parts are there?

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< 500 parts.

BTW: Where is the war? Not here! Where are the minimalists?

Peranders -

My pseudo-diy amp has about 20 parts. I guess in your eyes, I am a minimalist. ... ok ok ok ... I am a lazy person.

Just curious, why not use MAT02 and MAT03? They are supposed to be super high grade matched transistor pairs. I am assuming you use differential pair inputs. They could be replaced with them. Supposedly these make noise level below the level of passive noise of resistors according to TNT site.

(I am just mentioning because last night I just declined to sample MAT02/03 from AD. ... Yeah I am already regretting my choice.)

Tomo

Oh,

I forget. I can build 3 para-pushpull mosfet amplifier with one CHEAP chip. 74HCU04.

Heehee, my laziness never cease to amaze me.

Tomo

P.S. Some dude stacked them really high to make a speaker amp. Call that a crazy man. (He had to make a heatsink just for it.)

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MAT0x fits in the pcb, if you check closely.

Peranders -

That is not what I meant. What I mean is that wouldn't it be more expedient to have MAT02/03 than to have many transistors which you will have to match deligently? Spec says that MAT02/03 might offer lower noise level.

Tomo

My intention was to use only "normal" parts but option for "special" ones. I will get 400 pcs. of BC5xx to the cost of one MAT0x.

If you prefer MAT0x for some reason, just use them!