P68 ...upgrade ( ??? )

[east electronics]

i am well known to like simple circuits ...(ROD is also probably well known not to like people to f@@ck up with his circuits ...a thing that i find reasonable ... but for diy's sake ....lets have an argument )

how about common heatsink drivers and vas then add a VBE multipler not that really neded but a BD 139 can be fitted in about 5 seconds compaired to the two f@@cking diodes that no matter how many times or many ways that i had to be inovative never actually managed properly ....

then add an extra pair on the allready existing 4 outputs ( rod claims that even with 70 volt rails amp will be very happily producing 250W taking as a fact proper coolingand never go lower than typical of 8 ohms )

and then add a VI limmiter on the amp to make sure that you are half way done also taking as a fact that you will not go lower than typical of 8ohm and any case better safe than sorry ...

Question :
never seen a bootstrap that i recal with a VI limmiter and i dont really know exactly where the vi limmiter can be applied since the amplifier doesnt feature current sources there might be an issue with the Vi limmiter and it might be providing assymetrical limiting ...

to refresh your memory here is the schematic of P68 and let us have a nice argument after that

happy regards sakis

 

[east electronics]

anyone ???

 

[djk]

It might be interesting to use the ON Semiconductor ThermalTrak devices for the drivers.

http://www.onsemi.com/pub_link/Collateral/NJL0281D-D.PDF

VI limiting with a bootstrap CCS? Done all the time (page 17).

http://www2.yamaha.co.jp/manual/pdf/av/english/AFR/CR-420.pdf

 

[east electronics]

thanks djk i will make a few testings and post my results here

thanks

 

[danspy]

Hire is Something abut VI limiting in the P3a.

ESP Projects and Articles • View topic - P3A : short circuit protection on speaker output?

Good lack