I just finished my inverted gainclone using OPA541AP, 16V-0-16V 5A tran and 100K TKD step. The sound is really impressive.
But I wondering I have to turn on the step around 1.00-3.00 o'clock to get the same loundness as 9.00-11.00 o'clock from my other int'amp. Is there anything wrong? [ I normally found gainclone with step is enough gain for int' amp]
My amp is truely humless, even connected to my 97db isophon fullrange. I measured DC at my bidingpost around .4 and .5 mV. And voltage +- 24V after diod.
Any suggestion ???
But I wondering I have to turn on the step around 1.00-3.00 o'clock to get the same loundness as 9.00-11.00 o'clock from my other int'amp. Is there anything wrong? [ I normally found gainclone with step is enough gain for int' amp]
My amp is truely humless, even connected to my 97db isophon fullrange. I measured DC at my bidingpost around .4 and .5 mV. And voltage +- 24V after diod.
Any suggestion ???
the opa541 is built to work. it has an excellent "phase margin" and is stable at any gain. but its gain-bandwidth product is low. basically, that term is just as you would expect: gain*bandwidth = GBP. high gains mean low bandwidth.
the lm chips have a high GBP, but are not unconditionally stable, and require a gain around 10 to function.
as for the low volume, i can't tell for sure, but maybe you have something wrong on the current limiting feature of the opa541.
the lm chips have a high GBP, but are not unconditionally stable, and require a gain around 10 to function.
as for the low volume, i can't tell for sure, but maybe you have something wrong on the current limiting feature of the opa541.
Thank u so much Nuuk, but i still can not see the picture
Which picture?
This is the circuit that I used although I can't remember where it came from!
An externally hosted image should be here but it was not working when we last tested it.
Do u have inverted schematic?
No I don't.
What would happen if I remove R***, R5 and C7?
I would leave R*** in. R5, and I pesume that you maen C4, are the zobel network that you could leave out to begin with.
gain above is 33. non-inverting.
r5, c4 can almost certainly be remove. they are there to help prevent instability, but with the high gain and inherint stability of the opa541, they shouldn't be needed. if you have them, they won't affect things adversely though.
C1, R3 is the input highpass filter. R3 is required because the input needs some connection to ground.
R*** is the current limiting resistor. check the datasheet to find the appropriate value. IIRC it is permissable to short out the resistor, but check the datasheet first!
r5, c4 can almost certainly be remove. they are there to help prevent instability, but with the high gain and inherint stability of the opa541, they shouldn't be needed. if you have them, they won't affect things adversely though.
C1, R3 is the input highpass filter. R3 is required because the input needs some connection to ground.
R*** is the current limiting resistor. check the datasheet to find the appropriate value. IIRC it is permissable to short out the resistor, but check the datasheet first!
I have lowered the gain to 15 and it still too much with my active preamp and my 96db eff speakers.
Can you lower the gain of your preamp?
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