Maplin MosFET Amplifier Ga28f construction thread

Hello

Just made the new heat sink bracket .. this is just a trial fitment, better 3mm bolts will be used and the mounting bracket will be polished
Just shows what you can achieve when you put your mind on to it and stay focused

Is it made from one or two pieces of metal ?
Its quite a thick piece of metal to try to bend.
 
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Shame Maplins went under they were great for the non-corporate electronics enthusiast.

Yes totally agree .. they really helped me with my electronic journey, loved all the projects -- sound to light units etc
ended up selling cheap chinese crap just like Tandy / toys / helicopters etc

Shame they did not have a business plan like RS / Rapid / Farnell just to name a few ... Altronics and Jaycar from Australia are another good alternatives, even Velleman are going the same way in my opinion, could be the same for them if they are not careful, but I suppose electronics as a hobby is long gone - but you would think differently with the about of activity on this forum :)
 
I had a Maplin about a mile down the road from me.
They were great if I was missing a component for a build and I needed it straight away.
They were expensive so I bought most of my components from RS and Farnell.
It was pretty sad towards the end, 2 or 3 staff on and just me looking around in a huge building. The overheads must have been huge.
I was a customer since about 1980. In those days you went through the catalogue and filled in an order form with item codes and quantities, sent it off and 3 days later you would get back your order with some of the stuff missing !
 
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Might have a go at bridging a couple of amps now that I have my own supply of PCB's ..
 

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Bespoke Constructor
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A little progress tonight a few resistors mounted .. really like making this amplifier it's very satisfying / easy to make and mod if required ... no spider thin PCB tracks on this board or surface mount S*** ... who cares if there is a little bit of hum when compared to all the mass produced chip stuff and all the people who listen to music on their iphones over bluetooth !
I bet you a couple of these in mono block form with good quality components would give the owner many listening years of pleasure and would still be working 20 years plus when most stuff ends up in the tip. I feel like I have just gone back to 1985 to my local maplins store ... all warm and fuzzy
 

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Bespoke Constructor
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Hello just a few pictures to show very slow progress ... have used NOS 2sk176 / 2sj56 mosfets .. have a few in the workshop never been used.
 

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Bespoke Constructor
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Hello Nigel .. quick question for resistor R15 it states 4.7 ohm wire wound ? does it need to be wire wound or could I use a metal oxide resistor ? I did read at some point that it should be a wire wound resistor ? all the kits had been supplied with a wire wound type for R15 ? ... your thoughts ?
 

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Hello Nigel .. quick question for resistor R15 it states 4.7 ohm wire wound ? does it need to be wire wound or could I use a metal oxide resistor ? I did read at some point that it should be a wire wound resistor ? all the kits had been supplied with a wire wound type for R15 ? ... your thoughts ?

So long as it is 3 watts any type should be fine.
I would try not to use WW if possible.