I have seen a few variations on the active Baxandall bass/treble circuit, but I have only seen in depth analysis of the basic circuit shown here:
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However this circuit seems to be more fine tuned:
Can anyone elaborate on the effect of the components in the second example? It would be most helpful if equations were provided for gain/cut and the +/-3dB frequency point. I have read the original Baxandall article, but a more an in depth analysis of the variation would be appreciated.
(copyright image removed by moderation)
However this circuit seems to be more fine tuned:
An externally hosted image should be here but it was not working when we last tested it.
Can anyone elaborate on the effect of the components in the second example? It would be most helpful if equations were provided for gain/cut and the +/-3dB frequency point. I have read the original Baxandall article, but a more an in depth analysis of the variation would be appreciated.
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Can you use a simulator package?
It would be easy to input the five versions: no cut/boost, max treble cut, max treble boost, max bass cut, max bass boost.
The analysis is the difficult part.
It would be easy to input the five versions: no cut/boost, max treble cut, max treble boost, max bass cut, max bass boost.
The analysis is the difficult part.
The first circuit is better, in that it has less extreme variations at max boost and cut and also less interaction between the two controls. I don't understand in what sense the second circuit could be considered to be "more fine tuned"; I would say 'more crude'.
I use this variation
This is the frequencies response.
I wrote the simulation on my blog but using Indonesia language.
This is the frequencies response.
I wrote the simulation on my blog but using Indonesia language.
My assumption was that if the negative feedback baxandall circuit came first, then this circuit would be an alteration to improve the original. Why alter something with more components and more expense if it is more crude? I haven't simulated it yet, but I have seen this implementation enough to wonder why it is chosen and how it works.
The second circuit uses negative feedback too, so it is quite similar to the first circuit. It uses a single transistor (biased at quite low current) instead of an opamp, so much more distortion. The range of adjustment is far too high (set by the ratio of the pot resistance to the end resistors). The slider arrangements lack the components which in the first circuit help separate the two controls. The small electrolytics in the second circuit are just there for DC blocking, and are not needed in the first circuit.
In what sense does the second circuit come after the other one? It looks older.
In what sense does the second circuit come after the other one? It looks older.
Is the first a 'baxandall' at all? Don't u need two caps in both bass and treble ckt? As shown in ckt2.
I'm not sure exactly which arrangements qualify to be called a Baxandall. The treble control can have two caps either side of the pot, or one cap attached to the slider. Similarly, the bass control can have one cap across the pot or two caps from each end to the slider. The net result is very similar, but probably not identical.
To simulate the circuit, use a simulator.
To simulate the circuit, use a simulator.
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