Amp5 build journal: amplifier module finished

[enigma_swe]

Good day forum people, out of pure "luck" i decided to build the amp5 as a learning project. My intentions are to go slow and get to understand the whole process and enjoy my time doing so.

Which lead me to start off as in the picture..


So ok, the mood is set

I decided to check all components and stick em to a piece of paper showing which component it is and where it's supposed to go. This lead me to a few question marks that i just wanted confirmed before i continue putting things together. There are a few capacitors i'm a bit unsure of. So i decided to show it all in pictures (3 of them).

I wrote all the info on the pictures themselves, i hope they are easy to understand. Like on this first one with the 12 capacitors i'm not sure if they all are 0.1 pF 50V etc..








Many thanks in advance, i just want to confirm that i have right component at the right place, first step

/Andreas

[krilli]

Hi!

quote:Originally posted by enigma_swe

Those components look right [|)]

quote:Originally posted by enigma_swe

I decided to check all components and stick em to a piece of paper showing which component it is and where it's supposed to go. This lead me to a few question marks that i just wanted confirmed before i continue putting things together. There are a few capacitors i'm a bit unsure of. So i decided to show it all in pictures (3 of them).

I wrote all the info on the pictures themselves, i hope they are easy to understand. Like on this first one with the 12 capacitors i'm not sure if they all are 0.1 pF 50V etc..

That looks OK too

quote:Originally posted by enigma_swe

1 and 2 are OK - at least the same type of substitution has always worked for me in the past. Sometimes the kits are shipped with slightly higher value capacitors. Re. 3, it's probably OK to swap for slightly less capacitance -- does the BOM or assembly information say anything about that component's role or range of acceptable values?

quote:Originally posted by enigma_swe

That looks right



Ps. - the best way to make sure of this is to correlate the parts with what bag they came out of -- you should see either labels with the bag contents on the bags, or a BOM with the part type / bag number. For instance, this is about the only easy way to be sure about some capacitors in the surface-mount kit.



Pps. - I haven't built an amp5, and I'm not 100% sure about anything I'm saying, but I would build the amp like that myself, and all my amps are working, except for one I blew up - and that wasn't due to wrong parts, it was another type of stupid.

[pepolman]

The larger electrolytic caps can be considered an upgrade.
The larger the caps the greater the "smoothing" of the dc voltage.

[enigma_swe]

Ah that's perfect. all the capacitors that differed from the BOM had a higher capacitance (with the same voltage). So that's good then.. And there were numbers on the bags, but there're weren't any notes about what each bag contained in the bom, so i decided to just measure and write it down instead.

Just found it a little strange not knowing the voltage tolerances of some of the 0.1F capacitors, so i guess all 12 of them are rated for 50V's and the two separate 0.1F are for 100V since they are quite a lot fatter. L11 and L4 (last picture) are both non-polar i guess? (didn't see any markings on them, so i thought it was better to ask)

Thanks a bunch! Hopefully i'll continue making it into a complete build-thread.

[pepolman]

Yep, inductors are non-polar.
They will have some small amount of magnetic field that can interact with other components, but that generally only happens with larger values or much higher frequencies.

[Scratchy]

You must have read this article before starting the AMP5 [)]
http://hephaestusaudio.com/delphi/20...nd-amplifiers/

***It's so easy, everyone should be doing it***

[enigma_swe]

Allright, i'm starting to get somewhere. I am almost at the stage were i can connect the transformator to check the 5V from the lm317 (still waiting for the transformer to get here plus some connectors)



This of course raises some thoughts and questions which i thought i would post before setting up things.

So hopefully up until now i've put the right components at the right place and correct polarity on components that needs it. So my next step is to solder on those connectors and hook up the transformer with a slow fuse. It looks like i've done an allright job on the solder part so far, but what if there is a joint which isn't perfect what is the worst case scenario? (don't scare me here..

I am not 100% sure about where to measure the +5 is it on J10, and would this "close" the circuit and let the voltage pass-through which probably isn't a good thing since the board isn't fully assembled yet.

So yeah i'm still going slow trying to get a hang of the schematic on my path to knowledge

And i'll stay off the beer when i connect the power

[pepolman]

Until you close the J10 jumper, there will be no 5V to the amplifier section. If you measure from one pad of the J10 jumper to the power common you hopefully will see very close to 5V or nothing if you're on the wrong pad.

The pad that physically connects to the regulator outlet should be almost spot on 5V.

[enigma_swe]

Allright so let me see if i got this straight, i'm having the schematic in my hand while writing

The 5 volts should be measured between pad1 on J10, and the power common. The power common would be the "analog GND" (G1 or G2 on J2) or the "Power GND" which would be PGND1 or PGND2 on J3?

And apologize for these most likely trivial questions, but we're taking baby steps here

[pepolman]

The 5V power section is actually separated from the "power" section by the little inductor.

The measurement should be the same if you were to use either ground but technically you should use the agnd.