1000 watts amp

[rrrhhs]

http://www.afiata.com/wp-content/uploads/2010/05/Power-Amp-1000w-circuit-diagram.jpg


  Good day po sa lahat.............kailangan ko po ng opinion regarding this amp. circuit maganda po kaya to?

   isa po kasi sa mga choice ko to para sa project ko.........

  ano pa po kaya dapat baguhin dito if ever na may dapat baguhin....especially ung mga TO-92s balak ko po sana palitan ng
  A92s lahat ....at ung BD681 po ano po kaya magandang substitute para dito? ...............salamat po.

[TinTopHack]

http://www.afiata.com/wp-content/uploads/2010/05/Power-Amp-1000w-circuit-diagram.jpg


  Good day po sa lahat.............kailangan ko po ng opinion regarding this amp. circuit maganda po kaya to?

   isa po kasi sa mga choice ko to para sa project ko.........

  ano pa po kaya dapat baguhin dito if ever na may dapat baguhin....especially ung mga TO-92s balak ko po sana palitan ng
  A92s lahat ....at ung BD681 po ano po kaya magandang substitute para dito? ...............salamat po.

With +/-70V supply you could probably get 400W into 4 ohms. No way you can get 1000W.
 

[Roland]

With +/-70V supply you could probably get 400W into 4 ohms. No way you can get 1000W.
 

@ 1 ohm maybe you can get 1000w
Just add power tranny and install a pipe from your heatsink going to your refrigerator.

wherever your amp  your refrigerator must also be there. 

just kidding...
Subscribing......

[j a y k e z]

@ts ung link di ko maopen T_T

@ 1 ohm maybe you can get 1000w
Just add power tranny and install a pipe from your heatsink going to your refrigerator.
wherever your amp  your refrigerator must also be there.  

hehehe d2 ako natawa     

[rrrhhs]

        Tama nga sir ......................question is maganda po kaya ito kasi parang hawig ng konti sa isang amp ng altec lancing eh? cerrect me if i am wrong.....


http://www.schematicsunlimited.com/download.php?manu=altec-lansing&file=altec-lansing-9442-power-amplifier-schematic.pdf

paki enter nalang po ung code sa box.....

ano po sa palagay nyo sir.........may advice po ba kayo for parts subtitution?....salamat po sa mga reply..

[tony]

mali ang pagkakadrawing ng input ltp at cascodes.....

pwede kang gumamit ng mpsa92, or 2SC2240 na to-92's.....

wag mo masyadong pansinin ang watts, paganahin mo muna...

sa drawing kasi hindi maliwanag kung yung rails nya ay fully loaded or on stand-by...

yung pioneer spec2 power amp, ang standby rails nya ay +/-91 volts pero ang fully loaded rails nya ay +/-72 volts.....malaki ang psu sag nya.....

so sa schematic hindi mo malalaman ang power hanggang hindi mo na-aasemble, napapagana at nate-testing....

[tony]

ito yung sinagot kong post sa taas....

http://www.afiata.com/wp-content/uploads/2010/05/Power-Amp-1000w-circuit-diagram.jpg


  Good day po sa lahat.............kailangan ko po ng opinion regarding this amp. circuit maganda po kaya to?

   isa po kasi sa mga choice ko to para sa project ko.........

  ano pa po kaya dapat baguhin dito if ever na may dapat baguhin....especially ung mga TO-92s balak ko po sana palitan ng
  A92s lahat ....at ung BD681 po ano po kaya magandang substitute para dito? ...............salamat po.

[TinTopHack]

I agree with Tony. Initial look at the schematic reveals the following problems. As it is the amp will not work. If you are an adventurous type you can modify it to make it work. If not you are better off building other amps presented in this forum

[tony]

the questionable trannies MJE340 are current mirrors, the designer has a queer way of drawing schematics....the bias comepensation is likewise wrong...

[TinTopHack]

Tony, you are right. they are current mirrors if the ckt is redrawn.  On my first glance it looked like the cold junction compensation we used for thermocoouples. Thanks for pointing that out.

[rrrhhs]

 Thank you po sa mga inputs nyo mga sir..........kung ganon po pala eh...... dun nalang ako sa westrak amp.

mahirap na pong makipagsapalaran....... meron po ba kaung PCB ng westrak?....baka po pwede nyo akong bigyan ng kopya.....malaking tulong po un may katagalan po kasi mag design.... isa pa eh hindi ako sigurado kung tama ba magiging design ko hehe........eto po pala e-mail ko....... rrrhhs@yahoo.com

 maraming salamat po uli......thanks in advance!!

[TinTopHack]

Below I have redrawn the schematic to correct the mistakes seen so far so that the adventurous ones can build it. After a second look at this schematic, and considering the power transistors used (5 pairs), this amp could very well deliver 1000W into 2-ohm load because:

+/-70V rail could deliver 130V peak to peak or 46Vrms at the amp's output. With a 2-ohm load, 46Vrms will result in 23Arms load current. That's 1058 watts into 2 ohms.

[tony]

good job, TTH, i guess depending on the trannies used, the max rails +/-93 volts can be used on this topology using classAB, any demand for higher power needs operation using rail switchers, in 2 or 3 tiers and more output trannies.....

 i may yet build one of these myself....

[TinTopHack]

Tony, the 200V Vceo rating of the output transistors should allow +/-93V rails. But the input stage transistors, BC546 especially the upper part of the cascode input stage will see a Vcb of 93V - 15V = 78V (15V comes from the 15V zener at the base) and a Vce voltage of 93 - 14.4V = 78.6V. The BC546 can not handle this because its Vceo rating is 65V max and Vcbo rating is 80V max. The current source at the bottom will also see almost the same voltages so we need to modify the input stage to work with +/-93V.

The MJE350s of the VAS stage with their 300V Vceo/Vcbo ratings should have no problem with that. The same with the pre-driver transistors.

Build it? I wish I could also build this too but I can not afford it at the moment.

[tony]

mpsa42 can replace bc546 at higher rails...

[jiggins20]

subscribing.......

[tony]

there are a lot more issues wrt audio power amps, "power rating" is not the end-all and be-all......

such issues are sound quality, relates to how the amplifier recovers from overload, clipping behavior......

frequency response, slew rate also falls into this category......damping factor, which is the ability of the amplifier to control the speaker cones' movements....

thermal stability, is there enough heatsinking so that the output transistors do not go into "thermal run-away"

efficiency, how much power is drawn out from the power utility.....

power supply quality is also important, it is one-halp of the power amplifier, it determines if the power rating promised on paper can be realized in practice....

only by examining the completed amp can we know......untill you build any amp, you will never know how it performs......not by just looking at schematic diagrams.....these diagrams mean nothing on paper, the real or actual amp is what counts....

do not obsess with schematics, it does not really tell you anything at all.......

[rrrhhs]

 wow!!!!!!!! asssstig talaga ni sir.