AMP6 Sneaky - BOM does not match, does it?

[kai_sch]

Hi everybody,

I just started soldering my first amp. A AMP6 Basic Sneaky rev 1.2. Of course the sneaky does not contain the mounts and the connectors, but there are still a few things that do not add up between the part I received, the BOM and the drawing.

a) The BOM (and my delivery) contains 6 "Cap 50V Cer 0.1uF" in Bag 1, but there are only 5 references to the drawing (C16, C17, C20, C36, C50). Were does the sixth cap go? I guess C200, but could somebody please confirm.

b) My delivery did not contain the 2 "Res Ax. Met. Film 0.125W 3.4mm 931R" for R8 and R11 from Bag 1. These are new for rev. 1.2 of the AMP6. I wonder if it was an error, that they were not included, or if they are somehow part of the connectors and therefore are not included in the Sneaky version.

c) same as b), but for the red LED from Bag 5. Not needed for Sneaky or an accidental omission from the delivery?

I hope somebody can answer these questions, or should I write directly to the support?

Ciao

Kai

[FFF]

Not good.
a) -- (edit: it IS on the 6basic12 schematic, should be on that BOM too)
b) not good, got a 1k spare yourselves (or to construct it or via scavenging) ? else support.
c) should be there, LED2, error, 3mm. no spare yourselves? support.

[kai_sch]

Thanks for the quick reply FFF. I contacted support about the missing parts. I don even own a soldering iron, let alone spare electronic parts

C200 is in the AMP6-BASIC 1.2 schematic on the top left, just right of C20 and J2. Or just next to C20 on the BOTTOM board layout.

On an unrelated question: I plan to drive two 15W/8Ohm speakers and power the AMP6 from the 12V rail of my PC power supply, using the PC as a signal source. Anything that I should be aware of? (It'll be used in the low to mid volume range)

[FFF]

Yep, been stupid: was amp6rev12, not the basic. Forgot I'm on the netbook...stupid, stupid.
Euh...how're you gonna put the amp together with no iron?

8ohm on 12V. About 8Wrms. Should suffice, yes it will suffice.
Don't even have to consider speaker sensitivity. You'll hear.

Edit: 8Wrms is OK !! Don't fret, get busy.

[kai_sch]

I borrowed a good soldering station, because I figuered it would be a bad idea to learn soldering with a cheap one. But that also means that I have no electronic parts.

I did some reading, but have no experience at all. What will I hear? Is 8Wrms even too little to use it as 2.0 system on my PC?

[tuo]

a) The BOM (and my delivery) contains 6 "Cap 50V Cer 0.1uF" in Bag 1, but there are only 5 references to the drawing (C16, C17, C20, C36, C50). Were does the sixth cap go? I guess C200, but could somebody please confirm.

Yup, there it goes. See step 5 here: http://www.41hz.com/forums/entry.php...6-BASIC-SNEAKY

That capacitor reference has been changed, as you can see, in the picture there's rev 1.1 board which says C21 instead of C200.

[FFF]

Maybe I was not clear: 8Wrms is OK, you will hear good sound with good volume.

I did some reading, but have no experience at all. What will I hear?
Is 8Wrms even too little to use it as 2.0 system on my PC?

[tuo]

Yes, 8Wrms is quite much indeed. A normal sensitivity reading for a hifi speakers range from 85 to 95 dB/1W measured at one meter distance. At least here in Finland the working safety rules dictate that ear protection *must* be used when working in environments where sound pressure is above 85dB.

And another link to my blog: http://www.41hz.com/forums/entry.php...-Demonstration

Those speakers were driven by the AMP6-B that I assembled on site and they are also 8 ohm speakers. And yes, that was enough to fill the end of the lobby where we were with some radio noise. First, third and last picture give some indication of the space there.

[Scratchy]

BTW, the heatsink clamped onto the TA2020 in the blog pictures posted above is total overkill for this amp.
Some people run this without a heatsink, but a simple flat plate of aluminum (case?) will suffice in your implementation.

[kai_sch]

Just to report back: Jan was quick with a reply.
- The additional cap is indeed C200
- The LED and R931 are not part of the "sneaky"

I´ll keep "soldering" on then