FS: Maplin derivative 75WRMS lateral mosfet amp.
New build Maplin 75WRMS lateral mosfet power amp.
Uses Exicon laterals which cost me £20 for the pair.
Choice of TO3 or cheaper TO247 output transistors.
Requires power supply and heat sink.
Asking £29.99 plus p+p
p+p is £4.20 to UK and £12.99 to Europe and £18 to rest of world.
Nice detailed sound.
I took Maplin (Hitachi) circuit and added extra decoupling on front end. Added DC offset adjust.
Uses modern easy to find components.
New build Maplin 75WRMS lateral mosfet power amp.
Uses Exicon laterals which cost me £20 for the pair.
Choice of TO3 or cheaper TO247 output transistors.
Requires power supply and heat sink.
Asking £29.99 plus p+p
p+p is £4.20 to UK and £12.99 to Europe and £18 to rest of world.
Nice detailed sound.
I took Maplin (Hitachi) circuit and added extra decoupling on front end. Added DC offset adjust.
Uses modern easy to find components.
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Hi Nigel,
Is that a fully-built & tested stereo board. I guess it'll need a more substantial heatsink too. What are the psu requirements?
Is that a fully-built & tested stereo board. I guess it'll need a more substantial heatsink too. What are the psu requirements?
Its a mono pcb.
The small heatsinks were used just to test it.
Requires 18-0-18 VAC 150VA transformer, bridge rectifier, 10000uf smoothing capacitors and heat sink for 4 ohm version.
Requires 24-0-24 VAC 150VA transformer, bridge rectifier, 10000uf smoothing capacitors. and heat sink for 8 ohm version.
It was sold about an hour ago.
I have some bare pcb's if you fancy building your own ?
The small heatsinks were used just to test it.
Requires 18-0-18 VAC 150VA transformer, bridge rectifier, 10000uf smoothing capacitors and heat sink for 4 ohm version.
Requires 24-0-24 VAC 150VA transformer, bridge rectifier, 10000uf smoothing capacitors. and heat sink for 8 ohm version.
It was sold about an hour ago.
I have some bare pcb's if you fancy building your own ?
Hello nigelwright,
Any schematic and is there any unique feature about the amp ? what is the build difficulty ?
thanks
Any schematic and is there any unique feature about the amp ? what is the build difficulty ?
thanks
Last edited:
Its the same circuit as the Maplin amp.
I added extra RC decoupling to front end to get rid of hum.
I added DC offset pot.
I added footprints for both TO3 and TO247 footprints.
Its easy to build especially if using TO247 laterals.
I added extra RC decoupling to front end to get rid of hum.
I added DC offset pot.
I added footprints for both TO3 and TO247 footprints.
Its easy to build especially if using TO247 laterals.
I have some blank pcb's too. 100mm by 100mm
Comes with build instructions, parts list, schematic, power supply diagram.
£6.99 each plus p+p
p+p is £2.50 to UK and £9.99 to rest of world.
Comes with build instructions, parts list, schematic, power supply diagram.
£6.99 each plus p+p
p+p is £2.50 to UK and £9.99 to rest of world.
Based on 1980's Maplin 75WRMS lateral mosfet amplifier but with modern components.
Exicon lateral's fitted.
Improved front end decoupling to stop hum.
DC offset adjust.
Choice of TO3 or TO247 pcb footprints.
Exicon lateral's fitted.
Improved front end decoupling to stop hum.
DC offset adjust.
Choice of TO3 or TO247 pcb footprints.
