--- In
Homebrew_PCBs@yahoogroups.com, "d1camero" <a8723@...> wrote:
>
> Hi all, I am building a tube guitar amp PCB. It requires heavy
> copper on thick boards. I would like to use 1/8" boards, but cannot
> find any locally. Anyways, here are my plans:
>
> Toner transfer method using Phoenix TTS paper (all I can get here in
> Canada). Then I plan to etch using MG Chemicals Sodium Persulphate
> and hand agitation.
>
> Is this reasonable for this thick of copper, or should I try a
> different method. Any hints, tips, or related sites would be
appreciated!
>
> thanks
> Don
>
You could probably get this to work, but for thick through hole parts
in tube amps, I believe the reason for 1/8" board is stability in the
face of higher heat levels. Single sided is not going to cut it
though, as one thing that helps is having plated through holes to
hold the part mechanically in place. Supposedly, you should use
double sided just to have a solid metal eyelet holding the part to
the pcb. This is even if traces only run on one side. So for a high
quality tube amp built on a pcb, you should farm out the pcb
construction for the plated through holes.
Read this for more info:
http://www.aikenamps.com/PCBorPTP.htmIf you're going to homebrew you might want to try eyelets through a
plain (no copper) pcb. Here's more info:
http://www.eham.net/articles/16053Although using eyelets seems rather low tech, it looks like it is
considered a high quality (though labor intensive) construction
technique. Old Fender amps in the 50s and 60s (preCBS) used eyelets
and apparently they are still reliable.
Cheers,
Don