Help with basic amp design

[Mooly]

Thanks Mooly . Soldering is a problem for me now . I would have just soldered it up in the past . In have tried a capacitor to replace the resistor . I must learn this simulation stuff . I have never asked my friend to see that circuit . I imagine he remembers it as it got him his BSc . From what he said it was basically that . I have knock it together many times without success . I have found a properly biased class A or B works well with an op amp . Often I don't use loop feedback . I fancy in chips they have mastered this idea . It is usually said to be a distortion cancelling mechanism with no details ( OPA 604 if I remember . ) . I will do valves in future as I should be able to solder them . DIN plugs are out .

SANSUI AU-alpha 607NRAII

That Sansui write up is funny

On simulation...
That's how I felt and each time I looked at LTSpice it just seemed daunting but after reading Bob Cordells new book and the chapters on using Spice then it all started to make sense.

I would say try it. Download LTSpice and just run the file of this amp I posted and have a play.

 

[nigel pearson]

I thought I was going to get a great truth from Sansui as they seem to have solved feed forward . Nothing . The circuit makes no sense . Liked the ideas and it shows the Japanese have imagination . Forgive me if I am wrong , I think Sansui means clear mountain spring water .

http://keith-snook.info/Wireless-Wo...Current dumping - does it really work DCD.pdf

Andrew are you good at this type of maths ? I can do it however I haven't for years now ( 30 ) . Can we get a minimalist current dumper to work ? I have input if anyone wants to do this ? It would be a lovely gift to the penniless .

 

[AndrewT]

I am OK with simple arithmetic.
I cannot get my head around the hundreds of equations involved in AC analysis.

 

[nigel pearson]

My friend can do the type of maths . If it get's interesting I am sure he will help . I want to use this idea below as dumpers . I would even attempt germanium as in feed forward speed is not always so important . Realistically it will be BC 550/560 and BD 135/136 .

The below example is a slight variation on a common circuit . It has profound implications in a circuit like this . Perhaps class B will be preferred . Who knows ? Class G , now you are talking ( ultimate current dumper and better than most class D ) .

Anybody want to run with this ? Aim is 14 W into 4 ohms .

http://www.diyaudio.com/forums/solid-state/74861-single-darlington-line-preamp.html#post856982

 

[nigel pearson]

Simple amp

If I was new to electronics I think I would start with this . It might save years of trying other things . The distortion is the type I like best . I like zero distortion amps also . Not sure about the rest .

http://www.diyaudio.com/forums/solid-state/210116-tssa-simplest-symmetrical-amplifier.html