how to convert this amplifier to an 15/18V supply?

[No ideas]

my attemps werent succesfull and i also dont own an big enough heatsink and an transformer to complete it as is, by attempts i meant copy-ing the circuit into ltspice and changing the values, i also didnt have enough time.

 

[jan.didden]

Unfortunately, I also don't have a lot of time. 😀

Jan

 

[rayma]

You probably could scale it down successfully for moderate or high impedance headphones.

 

[ejp]

Define “weren’t successful”.

 

[No ideas]

output swing was awfull and it distorted a lot

 

[No ideas]

You probably could scale it down successfully for moderate or high impedance headphones.

no i just wanted an little around 5 watt amplifier

 

[jan.didden]

So why don't you show us what you got?
There may be a few easy things to complete it.

Jan

 

[No ideas]

nevermind i should stop wasting peoples time and just use ltspice for few minutes

 

[jan.didden]

Yes you did waste peoples time. Not nice.

Jan

 

[No ideas]

im sorry and i promise i wont do that again, im just an impatient teenager./gen

 

[xXBrunoXx]

Well I wanted to post the schematic .asc but looks like you already made it .
Model for MPSA92 here if u want it.

 

[No ideas]

i dont have the mpsa transistor so id rather substitute it

EDIT: i have one at school that is of dubious quality (to spec knockoff)

 

[xXBrunoXx]

660mA Quiss current . R7 will get hot . if u make it 0.33R the current will be a few tens of amps.

 

[No ideas]

im gonna use it for speakers it will get hot and thats why i have the apropriate 3w resistor

 

[No ideas]

and here it is an fully scaled down nelson pass zen amplifier, vr1 adjusts the output voltage to be at half of the supply, i heard you could add an extra poly or mkt cap or connect two output capacitors in parallel with eacch other and so on, an source resistor to decrease distortion and it seems to be quite good at it.

 

[No ideas]

the efficiency is horrible though

 

[xXBrunoXx]

and here it is an fully scaled down nelson pass zen amplifier, vr1 adjusts the output voltage to be at half of the supply, i heard you could add an extra poly or mkt cap or connect two output capacitors in parallel with eacch other and so on, an source resistor to decrease distortion and it seems to be quite good at it.
View attachment 1369843

Have you measured if you have half of the supply voltage before the speaker cap ? C1.
Also the current on M2. ?.

 

[rayma]

Isn't the Iq still too high for a small heat sink?

 

[rayma]

the efficiency is horrible though

It's a single ended amplifier, that is its nature.

 

[No ideas]

Isn't the Iq still too high for a small heat sink?

its not that small of an heatsink and im gonna use one per fet, my school has an container filled with old thermomix power supplies and they have these cool heatsinks that are 9x3,5cm