500W PA amplifier with Limiter

Request for a Subwoofer amplifier

Hi all,

it has been a nice read from past few days, lot of designs, and special thanks to apexaudio for sharing his designs with the community.

i love to DIY, and built a few of DIY amps out of
fw stk's
TDA7294,
lm3886
2N2955/2N3055, around 70W RMS, one pair of transistors(+- 35Vdc)
2n3773/2N3773 around 70W RMS, one pair of transistors(+- 35Vdc)

these are still doing their duty fine to drive mid and high frequencies,

i am in lookout for a amp to cover the lower frequencies, with power ratings for around 300W into 4Ohm load nominal usage would never reach this level, but i want some headroom while driving a subwoofer.

i have not procured any stuff so i can do it ground up,

regards
harsha
 
i have made b500.when i supplied -+24v the is ok.but when i supplied -+55v the + fuse blown.what could b wrong in here?
try to follow this as mr.apex said (try this one you can adjust bias with different value of R23 (use 1k trim-pot), and use 10R instead fuses, set bias to get 1V on 10R, measure value of trim-pot resistans and replace trim-pot with same value resistor or two to get same value). hope it can help :)
 
b500 tef tested with p.audio ,challenger c18el 1200w one sub and one top per channel,(300w per speaker in top)
powerful sound,
for diy members pls try to buy 15 inch speakers or 18 inch speaker, without good speakers u cant hear the powerfull sound.
useless of making powerfull amps.
 

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b500 tef tested with p.audio ,challenger c18el 1200w one sub and one top per channel,(300w per speaker in top)
powerful sound,
for diy members pls try to buy 15 inch speakers or 18 inch speaker, without good speakers u cant hear the powerfull sound.
useless of making powerfull amps.

Nice work, I suggest some of my speaker box design for more powerfull sound.
Regards
 
Member
Joined 2010
Paid Member
Toshiba 2SC3281/A1302 have been obsolete more than 13 years. Virtually all these parts still available have been fakes for many years. Perhaps you have no clue what you really have and so it would not make sense to compare them with anything unless you really can test them at high power. At 500w, you are playing with fire using bogus components.
Wingshing and Mospec (Taiwan) make fair clones, however. You can use them though Vceo is only 200V compared to 230V. Who is the manufacturer marked on your transistors?

If the Toshiba 3281/1302 parts are genuine, they will be worth more to you as collector items to sell, than any 500W amplifier!
 
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Toshiba 2SC3281/A1302 have been obsolete more than 13 years. Virtually all these parts still available have been fakes for many years. Perhaps you have no clue what you really have and so it would not make sense to compare them with anything unless you really can test them at high power. At 500w, you are playing with fire using bogus components.
Wingshing and Mospec (Taiwan) make fair clones, however. You can use them though Vceo is only 200V compared to 230V. Who is the manufacturer marked on your transistors?

If the Toshiba 3281/1302 parts are genuine, they will be worth more to you as collector items to sell, than any 500W amplifier!
=) thanks for the reply, this one is toshiba made in japan.. i have four of this..=)