Crescendo Elektor Modify Suggestions

robydream

Member
2010-07-12 12:02 pm
Hi.

I was reading article of Crescendo posted in Elektor 1982. I would like to improve it and then build.

Idea is to Make Input Stage complamentary differential with current-mirror and constant current source that is 2.2mA.

When i im simulating in CircuitMaker i im getting oscillations from output. How can i simulate input stage to see if it works and not oscilating...and how to measure Slew Rate and Noise.

If anyone needs i can redraw circuit in LTSpice...and attach here schematic.
Many Thanks.
 

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most of these circuits are hfe/beta and so on depending most of builders eventually end up with stability issues .Proper pcb, and far more important proper thermals , together with absolutely perfect semis matched really very closely may be able to produce some usable result .

It was enough to blow your breath above the input stages to create 100mv offset in the output .builder that made bigger version with blowers that actually blow air both in the heatsink and the board ( by design mistake ) made the amp impossible to stabilize ...

Costumer of mine described cresendo designs around 4 options :

Option 1: find the designer and hit him hard ( hospital level at least )
Option 2 : paint boards deep blue trash them in the sea
Option 3 : Use ready made boards as a fire starter in your fire place
Option 4: Issue white paper to study coloration /smell and variations of burned drivers /outputs

:D:D:D
Kind regards
sakis