how to upgrade amplifier for more power?

[DigiSoft]

It is car amplifier.

Ok so I've re-winded the toroid transformer and now I get +-50V
I've added bigger and stronger rectifiers and I added +1 switching driver for the frequency. It is using TL494 for the pulses. It is running very cool.

Now what wattage can I get from these 50V. I can't go over 50V because my toroid is small and will start to warm.

I want to know what wattage can I get because when I know that I'll know what amp stage to look for.

 

[wahab]

Be aware that TIP2955/3055 and their likes are not
100V Vce devices..
besides, they won t stand the possible power of 130W to 140W/8 ohm
allowed with such a high voltage.

You should use two pairs at least, and more rugged devices, like the
TIP35C/36C.

Same applies to the drivers, they must be 100V as well and
powerfull enough...TIP41C/42C should do it..

 

[DigiSoft]

Be aware that TIP2955/3055 and their likes are not
100V Vce devices..
besides, they won t stand the possible power of 130W to 140W/8 ohm
allowed with such a high voltage.

You should use two pairs at least, and more rugged devices, like the
TIP35C/36C.

Same applies to the drivers, they must be 100V as well and
powerfull enough...TIP41C/42C should do it..

That's what I wanted to hear. So now I should use another pair right?

Ok, I'll make separate PCB and I'll attach another pair of these + 5W 0,22 ohm resistors and hope it works .

When you say drivers, do you mean drivers for the TIP transistors right?
Right now the drivers are B631 and D600. Are they ok to drive two pairs of TIP transistors?

I'll make picture so you can help me out.

 

[wahab]

Right now the drivers are B631 and D600. Are they ok to drive two pairs of TIP transistors?

.

They are 120V, so they will hold the voltage, but they are
only 1W TDP if not used with a heatspreader.

They should be fixed on a radiator as well, so they can disspitate 8W
maximum..

I would add that personaly, i would use more rugged devices
to drive the power trannies.

 

[DigiSoft]

Wahab thank you so much my friend here is the picture to help you out.

Please, what should I change?

I want to use another pair of 3055/2955 and I want to have amp capable to deliver 120W in 8 ohm.
I am sorry I don't have schematic. This is some noname amplifier but I want to make it stronger. I know I can buy another but I really want to make this one.

Thank you to all.

 

[wahab]

TIP2955/3055 of STmicro are 60Vonly, so there s a big risk
of breakdown.

Yo should use higher voltage devices , TIP33C/34C are the same
devices as these ones ,but with a 100V vce...

Also, check that the caps can hold the increased voltage;
particularly the big ones, which are connected to the supply rails.
They must be 50V.. If they are 35V only, it will be unsafe..



TIP3055 Datasheet pdf - COMPLEMENTARY SILICON POWER TRANSISTORS - SGS Thomson Microelectronics

http://www.datasheetcatalog.com/datasheets_pdf/T/I/P/3/TIP33C.shtml

 

[DigiSoft]

Ok thanks, but what should I do about those small transistors like A1266 or C3198. Are they save to operate at 50V. Should I replace them too.

 

[wahab]

Ok thanks, but what should I do about those small transistors like A1266 or C3198. Are they save to operate at 50V. Should I replace them too.

They are 50V, and should hold the voltage , as they
are surely used for the differential and its current sources.

To be cautious, i would replace them with 2SA970/2SC2240
which are 120V devices.

 

[richie00boy]

You can find their datasheet and check the Vceo rating. It must be at least 100V to be safe with +-50V rails.

Be careful with this project, the current will go up a lot so tracks may burn on the PCB.

 

[DigiSoft]

You can find their datasheet and check the Vceo rating. It must be at least 100V to be safe with +-50V rails.

Be careful with this project, the current will go up a lot so tracks may burn on the PCB.

Ok I'll check that but do you think I should also change resistors?
I am not concerned about the Wattage of the resistors I am concerned about their value. Because I changed the voltage, maybe some resistors need to increase value?

 

[richie00boy]

I would leave them, it may be better to change their value but it becomes a redesign if you start going that way, turning into a monster project.