AudioSource AMP200 - help needed

[Leo_Gnardo]

anyone care to guess what caused the failure in this amp? with R01 & R02 jumped and C10 replaced, the amp powers up.

is it worth thinking about upgrading the amp to a AMP300? there aren't that many components to replace, and as far as I can tell the transformer is the same.

Can take a guess that c10 just quit for no apparent reason. ##it happens...

About upgrading, your amp works now right? I'd say, don't press your luck.

[Dave H]

It looked like Spam-o-matic DID work here

Thanks a million Steve

[Jiji]

@Leo_Gnardo
yes it works. it's been on for about 6hrs.
as I'm chilling out and waiting for someone to encourage me to upgrade it , I am making 2 little heat sinks for the IC01 & IC02 (7815&7915).



Thanks Steve A.

[Leo_Gnardo]

It looked like Spam-o-matic DID work here so thread is still open.

And thanx X 26.77 million here! YOU DA MAN!

[g1]

Thanks Steve.

[Jiji]

Heat Sink for IC01 & IC02



in the end I decided to go w/ a single heat sink not 2 smaller ones. it's made out of a AMD CPU heat sink. it's shape is intended to draw the heat away from the components around... it feels sturdy mounted on; there is no need to anchor it on the actual board. it acts like a springy clamp... the little screws are for security reasons and looks
used a little silicon based thermal compound even though the fit and surfaces are smooth.



because I didn't get the enthusiasm I was hoping for (haha) regarding an amp300 upgrade, what should I replace before I close the amp?
the schematics say 0.1uF/100V for C09 & C10. as far as I can tell, the board was fitted w/ ceramic-disks, 50V.
also, should I replace the little caps C07 & C08 w/ bigger ones?
should I use the recommended values for the R01 & R02?

Jazz P Bass, DrGonz78, The Dude, mozwell, Steve A, Leo_Gnardo, thanks everyone for your time. I appreciate it!

[g1]

Did you use insulation between the regulators and the heatsink (mica or silpads)? If not, you are shorting the 2 regulators together which may blow things up.
Also, you will need to secure the heatsink to the board. It may seem that the components can hold the weight, but when the amp gets moved around, the weight of the heatsink may cause broken legs on those components.

[DrGonz78]

Did you use insulation between the regulators and the heatsink (mica or silpads)? If not, you are shorting the 2 regulators together which may blow things up.
Also, you will need to secure the heatsink to the board. It may seem that the components can hold the weight, but when the amp gets moved around, the weight of the heatsink may cause broken legs on those components.

Very good point indeed!! yikes!! I think the OP has good knowledge thus far and would not have made such a mistake. Besides it seems like those TO-220IS packages are all plastic without the metal backing tabs. Here is the datasheet, I think... Jiji please confirm that they are all plastic tabbed versions, like my attached photo.

Edit: G1's point about securing the heat sink to the board is very important and the weight of that thing over time is not going to be a good thing. There are some slip on heat sinks available online that fit snug right onto the regulators.

[Jiji]

@DrGonz78 & g1
it is non conductive material as DrGonz78 stated. these regulators use one of their legs for cooling purposes, saw it somewhere in a data sheet. thank you very much for pointing this aspect out!!!

I soldered the regulators after I attached the sink so there is no permanent torsion on the legs. the weight (inertia) of the assembly seemed negligible considering it's soldered in 6 points. I'm willing to reconsider the whole approach :]

[Tom Phillips]

...I'm willing to reconsider the whole approach :]

My thoughts... Although there are always better and more robust fixes, the more you mess with it the more chance there is to introduce another problem. If it were my amp I'd use it as is because it's going to live on a shelf in low vibration conditions AND you, as the owner, now know how to work on it if there are further problems.

[Jazz P Bass]

TO220 heatsink options: https://www.google.com/search?q=to22...7qD10Q_AUIBygC

[g1]

Ok, if those are the plastic encapsulated regulators then you don't need insulators.
And as Tom Phillips noted, if it's going to sit somewhere and never get moved around much, then go ahead and use it like that. My concern was that the heatsink looked very top-heavy.

[Jiji]

http://www.head-fi.org/t/198564/pape...5#post_2387348
post #22

@Jazz P Bass
thank you for the link. look what I found. a study. beautiful.


this is version 2. it rests on the board. it can be glued w/ a drop of silicon. it has increased surface and airflow, reduced top weight. it looks sexy.
anyone care to guess the weight of the heatsink? ;]



the work started on v3. it's retarded.

[DrGonz78]

[ATTACH=CONFIG]37409[/ATTACH]
http://www.head-fi.org/t/198564/pape...5#post_2387348

I especially like the paper clips!! Also, what I have read is that you need to find old copper pennies to really make them great heat sinks.

Jiji I have to commend you as well on your abilities to cut metals and create your own heat sinks out of left over materials, very cool.

[Jazz P Bass]

A 1909S VDB penny should work rather well.

1909 s VDB ICG MS63 RB Lincoln Wheat Cent 617NAM | eBay