P3A - getting more power

[tobias_svensk]

Hi there !

I´m wondering a little bit over the P3A, I have 5 pcs of the
MJL4281A
MJL4302A
MJE15034
MJE15035 each

Let say that I want to double the effect, then its possible to just add one more section of the driver and power transistors and the 220 & 0.33 ohms resistors right?

and if I want to keep then cool I could even add one more section (3 total sections)

And of course buy a bigger transformer (maybe 500VA for 2 sections or 600-750VA for 3 sections)

Would this affect the soundquality?

Thanks in advance


P3A

 

[Freddie]

et say that I want to double the effect, then its possible to just add one more section of the driver and power transistors and the 220 & 0.33 ohms resistors right?

Do you want to double the power into the same impedance? If so you must increase the rail voltage quite much, and you will need to change a lot of parts.

/Freddie

 

[Freddie]

BTW: I'm running my P3A at +/-52V, it produces around 200W RMS into 4-ohms load, with a 500VA transformer and 2*47000uF caps per channel.

/Freddie

 

[tobias_svensk]

Thanks for the reply Freddie

Yes, something like +/- 50V

Are you running your with one pair/channel or more?

I just thought it could be good to parallell some more transistors if the single pair gets hot in the first place, maybe they doesn't?
The total heat would probably be the same, but it could lenghten the life of the transistors. (I´m a beginner in this so I´m only guessing 🙂 )

The JHL also looks great, maybe thinking of that piece to, or the AKSA 55/100 (are schematics available for them?)

Cheers

Tobias

 

[bigparsnip]

Hi, if you have a read through this thread you should find some answers on how to add more output devices sucessfuly to this design. IF you skip straight to the end there is also a ful schematic that I reworked with few different components to allow the design to be run stabily at a higer voltage than the initial circuit was bult for.

Andrew.