Very simple quasi complimentary MOSFET amplifier

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AKSA

AKSA

Member
Joined 2001
aksaonline.com
Yes, Gareth, I know what you mean...... I spend tens of hours on my layouts, and the last 10% of this effort seems to add a brilliant sheen to the final artform.
I certainly know about it; but others may not notice because they don't know the evolution. To me, this is the best aspect of amplifier design. The schematic is dashed off on napkinns in cafes after three coffees..... then honed in frequent ten minute sessions over a year.

Then careful analysis with LTSpice, then the pcb, then the proto, and then the production proto with all the refinements inserted to make it easy to make.

All this takes about a year. It's very slow work. But you know all this!

Cheers,

Hugh
 
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prasi

prasi

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Joined 2014
sites.google.com/site/analogdesign1234/
Paid Member
Bigun said:
There's something proper about making a layout 'look and feel right' if you know what I mean. Electrical or not, it's that feeling when something is right that often makes a project special.
Click to expand...

Hi,
I get that feeling when I join all 90 deg traces and pads with a more elegant 45 deg angle. Dont know if its electrically significant but I like doing it and spend way too much time on it.
reg
prasi
 

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thimios

Member
Joined 2009
very simple

It is singing!
Using a 500R trimer for offset set i'm getting -250mV offset.
Increasing 33k to 51k it was possible to get 0mV.offset.
 

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thimios

Member
Joined 2009
very simple

The rest.
1st Offset with 500R trimer and 33k to base of inp tran.(-250mV)
2nd increasing 33K to 51K.(0mV)
In this first test two regulated power supply was used starting from +/-10v and ended up to +/-20v
 

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thimios

Member
Joined 2009
Ranchu32 said:
Great work Thimios & thanks for sharing pics!!

Different rail voltages will require some fine tuning of these values as you have noted.
Click to expand...
Hi Ranch thanks you,AKSA and Prasi.What is the optimum bias setting?
What is the normal and what the maximum voltage for this amplifier?
My opinion about this amplifier (from a little hearing test) is that play lovely, something like a tube amplifier.
 

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nzlowie

Member
Joined 2015
Hi guys, I've Hugh has recommended I check out this amp.... I'm going to print all these posts at work tomorrow so I can study them.... is the final PCB available from anyone?

Thanks for now..... sure there will be more questions to come!

Regards Dave

Sent from my D5833 using Tapatalk
 
xrk971

xrk971

Founder of XSA-Labs
Joined 2012
etsy.com/shop/XRKAudio
Paid Member
thimios said:
Hi Ranch thanks you,AKSA and Prasi.What is the optimum bias setting?
What is the normal and what the maximum voltage for this amplifier?
My opinion about this amplifier (from a little hearing test) is that play lovely, something like a tube amplifier.
Click to expand...

The 20v rail voltage is nice from standpoint of cheap and easy to use PC SMPS bricks. Mine are 19.5v 4.6amp and two in series makes for a pretty slick little amp. This definitely looks like a lot of fun - tube sound is nice :)
 
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