Buffer and highpass combined

M

mikee55

New Member

• Jan 20, 2006

• #1

Hi all,can anyone give me a circuit which combines a 12 db highpass at @7hz and acts as an input buffer.I need this as a first stage in a subwoofer circuit,my design uses 8 op-amps and I would like the unit to have a low power consumption and thought combining the above would reduce the demand by 1 op-amp.

 

R

Russlk

New Member

• Jan 20, 2006

• #2

This may be what you want?

 

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M

mikee55

New Member

• Jan 20, 2006

• #3

Cheers Russlk

Thanks.mikee55

 

Roff

Well-Known Member

• Jan 20, 2006

• #4

For 7Hz, you need to change the caps to 100nF.

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Jan 21, 2006

• #5

Bear in mind though, this circuit really requires a buffer in front of it, to give it a low impedance feed - but as long as the circuit you feed it from has a low impedance output you should be OK.

 

M

mikee55

New Member

• Jan 21, 2006

• #6

Thanks guys

Cheers for the answer

 

R

Russlk

New Member

• Jan 22, 2006

• #7

I ran a simulation and the cap values in the circuit are correct. The design program was written 30+ years ago, so I am glad to know it has not had an error that long!

 

Roff

Well-Known Member

• Jan 22, 2006

• #8

Russlk said:

I ran a simulation and the cap values in the circuit are correct. The design program was written 30+ years ago, so I am glad to know it has not had an error that long!

Click to expand...

What I was pointing out was that he was asking for 7 Hertz cutoff, not 72 Hertz. That's why I said change the caps to 100nF.

 

M

mikee55

New Member

• Jan 22, 2006

• #9

Thanks guys

Your help is gratefully appreciated.So can I fabricate a PCB now?
Kind Regards mikee55

 

R

Russlk

New Member

• Jan 22, 2006

• #10

Dang! I need new glasses, I could have sworn it was 72 Hz.