my little QUASI AMP

[sekhar]

Here is the schematiccs for Little QUASi AMp in simulator it run fine with THD ratings as low as 0.01% lets see wat do experienced people have to say

An externally hosted image should be here but it was not working when we last tested it.

regards
sekhar

 

[event horizon]

Give it some emitter degeneration on the LTP & check the distortion then, should make the whole thing more linear.

100 ohm should be fine on each emitter 🙂

 

[sekhar]

here is updated schematic as suggested by EVENT HORIZON .............. sorry to say but after addding the resistor in emitter of the LPT the THD rating actually increased from 0.01 to 0.03


regards
sekhar

 

[sekhar]

the schematics

An externally hosted image should be here but it was not working when we last tested it.

regards
sekhar

 

[event horizon]

lol, can't win them all i guess 😀

 

[AndrewT]

Try increasing the LTP tail current to restore the LTP gain to what it was.

Then try adding a low value emitter resistor to the VAS.

 

[sekhar]

seems that I should go and make pcbs straight forward the design seems to good enough wat say every body any more modification needed ?????????????????



regards
sekhar

 

[godfrey]

I don't think you need the diode between the emitter of the BD140 and the output. That is good for bipolar quasis, but not with mosfets.

Otherwise it looks OK, so long as the output bias is set correctly.