Inv Gain Clone with on board PSU

[cb951303]

thanks

 

[anbello]

at last i did it

After near six month of inactivity on this front i found the time to send eagle file to olimex to have my pcb professionally done.
The first listening impressions are really positive, i have to try it without the .1 Rout and/or zobel network.
In the attached images the end result.

 

[anbello]

img2

 

[anbello]

img3

 

[anbello]

img4

 

[Greg Erskine]

hi anbello,

Looks really good. I great to actually finish a project especially when it works well.

Any comments on Olimex. Did you have any issues with the silkscreen?

regards

 

[Russ White]

Nice amp! Very good work. Enjoy!

 

[anbello]

Thanks a lot Greg and Russ really nice comments for my first work.
As for Olimex i can say good overall quality for the price. The silkscreen is not so good, especially with one of the two boards as you can see.

 

[anbello]

second board

 

[Greg Erskine]

Thanks anbello for the feedback on Olimex. They look good value for DIYing, especailly during the prototyping stages. Did you increase the thickness of the silkscreen to 10 mil before sending it to Olimex?

Anymore listening tests?

regards

 

[anbello]

Thanks anbello for the feedback on Olimex. They look good value for DIYing, especailly during the prototyping stages. Did you increase the thickness of the silkscreen to 10 mil before sending it to Olimex?

Anymore listening tests?

regards

Hi Greg,
for the silkscreen i used the ulp script from olimex on this link:
http://olimex.com/pcb/silk.html
to have it how they require.

New listening tests: double blind with a famous NIGC (LM3886), for me no difference, for my wife (better ears then mine) my amp is a lttle bit more "open" and "airy" (these terms are my bad translation, i don't know if are correct to understand).
Of course these are only our opinions.
I'am waiting for my friend (the guru) with golden ears for a more complete review.

ciao
andrea

 

[Greg Erskine]

Thanks again.

 

[peranders]

Thanks a lot Greg and Russ really nice comments for my first work.
As for Olimex i can say good overall quality for the price. The silkscreen is not so good, especially with one of the two boards as you can see.

Olimex uses real silkscreen but many manufactures have stopped using this method. My supplier uses white photorestist which means that you can "print" really small details.

Nice job, anabello! up:

 

[anbello]

Olimex uses real silkscreen but many manufactures have stopped using this method. My supplier uses white photorestist which means that you can "print" really small details.

Is your supplier an internet based service (like olimex)?
In this case can i have the name?

Nice job, anabello! up:

Thanks a lot P-A

ciao
andrea

 

[Nordic]

... for my wife (better ears then mine) my amp is a lttle bit more "open" and "airy" ...

She's supposed to say that... anything else whould be like you saying "those jeans makes your behind look big honey" even if its true...

 

[dfdye]

She's supposed to say that... anything else whould be like you saying "those jeans makes your behind look big honey" even if its true...

LOL!!! My wife just wonders how much it cost, asks me why I wasted so much time "messing with something that works fine now," complains that I never built grills for my speakers, and then takes my recliner in the sweet spot of the den since "it sounds better in your chair."

 

[Burnedfingers]

I may have overlooked it but do you have the printed circuit board files that you might share? I would like to have the board manufacturer that made your boards make up several for me to try. I like the concept that you have come up with.

 

[jpg]

burnedfingers,

Andrea kindly shared this back in April:

http://www.diyaudio.com/forums/showthread.php?postid=895880#post895880

This obviously isn't the exact file that he sent to Olimex, though (I see a couple of minor tweaks and one different part value, C8).

Andrea might want to comment on this or share the latest revision of his layout.

jpg

 

[anbello]

This is the version i sent to Olimex to obtain what you see in posts 48 and 49. I only added the name of my project and site.
Anyway there are some thing to modify:
- the package of the LM3886 is wrong (in pads positions an drill), i got it on the net i don't remeber where, and i had some problems to fit this component
- the pads diameter for the resistance from the eagle lib rcl.lbr is too small (the drill is ok).

I am working (in the spare time of the spare time of the spare time ...) to get a better layout with better package and then make a kit to offer on my site.

ciao
andrea

 

[anbello]

I forgot to say that i release my projects as "open source" only for DIY purpose and not for commercial use.

ciao
andrea