oh sorry, they're right here... guess i should have looked first!
http://www.siliconchip.com.au/html/pcb04feb.htm
http://www.siliconchip.com.au/html/pcb04feb.htm
Hi,
the amp is firstly designed for MJ15003/MJ15004 output transistors. If I use 2SC5200/2SA1943, the currents could be lower, because the 2sc/2sa pair has higher gain.
Anyway the circut works fine with 2sa/2sc outputs too, but 2×12mA current in the second diffamp is unnecessary. We can use only for example 2×6mA, and than the MJE340/350 transistors shouldn't be heatsinked.
This design is not the state of art, but as I wrote, for PA purpouse its enough.
But we can keep the currents higher, with heatsinked MJE trans'. Higher current here means better quality.
If the offset isn't bigger than +/-100mV (in the most cases it not higher, but I don't matching the transistors, so it can be), the 100k resistor (that goes from the offset-circut to the input) need to be eliminated, because offset adjust is unnecessary.
Regards,
the amp is firstly designed for MJ15003/MJ15004 output transistors. If I use 2SC5200/2SA1943, the currents could be lower, because the 2sc/2sa pair has higher gain.
Anyway the circut works fine with 2sa/2sc outputs too, but 2×12mA current in the second diffamp is unnecessary. We can use only for example 2×6mA, and than the MJE340/350 transistors shouldn't be heatsinked.
This design is not the state of art, but as I wrote, for PA purpouse its enough.
But we can keep the currents higher, with heatsinked MJE trans'. Higher current here means better quality.
If the offset isn't bigger than +/-100mV (in the most cases it not higher, but I don't matching the transistors, so it can be), the 100k resistor (that goes from the offset-circut to the input) need to be eliminated, because offset adjust is unnecessary.
Regards,
hello guys
seen this studio 350 and since i like so much simple constructions i wonder if i can get any more information specified about this amp .....
i ve been reading the post through ....and my applications are small pa application where power stability and capabilty on working 100% of power for many hours is the target ( often above quality )
supposed that the rest of the construction is perfect (proper trafo , caps , softstarts cooling ,ground loops and goes on ) is correct do you recoment this amp to my applications ???
thank you sakis....
seen this studio 350 and since i like so much simple constructions i wonder if i can get any more information specified about this amp .....
i ve been reading the post through ....and my applications are small pa application where power stability and capabilty on working 100% of power for many hours is the target ( often above quality )
supposed that the rest of the construction is perfect (proper trafo , caps , softstarts cooling ,ground loops and goes on ) is correct do you recoment this amp to my applications ???
thank you sakis....
sc350
The Studio 350 is 200W/Ch. 8 ohms and 350W/Ch. 4 ohms
Electronics Australia no longer exists. EA copyright is now owned by Silicon Chip, who also have their back issue articles.
The Studio 350 is streets ahead of those old EA designs.
Carlos, surely you are joking about any modern amplifier with any pretensions to quality, using those slow and antiquated 2N3055/2N2955 ?
Regards
Sandyk
The Studio 350 is 200W/Ch. 8 ohms and 350W/Ch. 4 ohms
Electronics Australia no longer exists. EA copyright is now owned by Silicon Chip, who also have their back issue articles.
The Studio 350 is streets ahead of those old EA designs.
Carlos, surely you are joking about any modern amplifier with any pretensions to quality, using those slow and antiquated 2N3055/2N2955 ?
Regards
Sandyk
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