| odysseybmx414 |
| anybody try opa549 biased into class A?? |
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| sss |
how can u bias the chip intu class A?:rolleyes:
the bias is internally set for class ab operation |
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| carlosfm |
| quote: | Originally posted by sss
how can u bias the chip intu class A?:rolleyes:
the bias is internally set for class ab operation |
The same way as you can bias any op-amp.;) |
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| odysseybmx414 |
| how exactly would that be done if im using a +-21v supply? i dont have any transistors so thats out of the picture unless thats the only way to do it. is there any other way? i heard of using a resistor from the neg sup rail to output but i dont know what size etc. any tips? |
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| carlosfm |
Search around, I tried it with the LM1875.
Didn't like the results, though...
Yes, you can use high wattage resistors. |
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| sss |
| quote: | Originally posted by carlosfm
The same way as you can bias any op-amp.;) |
oh , u mean that way , thats not really a class a operation .
anyway all thats gonna do is heat up the poor chip . |
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| carlosfm |
| quote: | Originally posted by sss
oh , u mean that way , thats not really a class a operation .
anyway all thats gonna do is heat up the poor chip . |
Yes, it heats a lot. It's not pure class-A, of course.
If I remember, I biased up to around 500ma.
Hot heatsinks...:hot:
The sound was too smoooooth for my taste, the more the bias the more the smooothness. Then the detail vanished.
It will surely work better (but probably not well) with VERY easy to drive and sensitive speakers, but why bother? |
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| tschrama |
no no no no that's a .. well let's say.. less elegant way to do it.. but ...NP has published a few pdf ideas to play around with chipsamps .. one of those ideas was to use 2 power opamp in a balanced config, eg 2x lm3886 , biasing them at some arbitrairy Iq.. so that the work in class A PushPull ...
anybody remember that theads' name? |
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| odysseybmx414 |
| NP?? whats this pdf? |
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