NCC300 NAP 135 Avondale Upgrade/Tuning

[Joe Hart]

Was at Avondale Towers briefly before christmas and got some slightly blurry phone photos of a NAP135 with the NCC300 board Les has invented, has some clever tricks like a fan that adjusts it's speed when it needs to.
Apparently these run at ~120w, with loads of output current.
Also has speaker thump protection - I think.
All you need is a NAP135 chassis - unsure if transformer is OEM or not.
It fits perfectly onto the NAP135 heatsink

Anyway sounds like a cool project so thought i'd share some photo's.

 

[chiily]

Wow... they look the biz... I'm hoping PCBs are available.

 

[LesW]

Blabbermouth.....

 

[Joe Hart]

Blabbermouth.....

Haha you did give me permission.
It's an exciting project

 

[Pete MB&D]

Les, are you turning the caps round to reduce the length of wire between the rectifiers and caps?

Pete

 

[LesW]

Les, are you turning the caps round to reduce the length of wire between the rectifiers and caps?

Pete

No Pete, the extra small resistance of the cable form helps in some cases to reduce the charging spikes.

Tip: don't be too anxious about interface losses - they can sometimes help.

Where I have eliminated a log jam however, is to dial the thermal trip and its thin cabling
out of the equation. It seems nonsensical to pay £££s in special mains cables only to
have the current pinched off by a length of 3A cabling. The thermal trip in this example
only carries relay current for the soft start.

 

[337alant]

They look absolutely superb Les

Alan