[sdiy] percusion synth design and problems.

[John L Marshall]

Jim Patchell is the king of bypass.

Put a 0.1uF at each opamp supply to ground.
Unused inputs are generally very high impedance and will act like an
antenna.

Are you doing this work on one of those white proto boards? A ground plane
will help a lot.

I had a friend that lived next to an over the horizon radar station. He
stereo had a periodic bizzt. The ultimate solution: Put the stereo in a old
refrigerator. ground the refrigerator. Use shielded wire to the speakers.
Ground the shield to the speaker frame.

Take care,
John
www.sound-photo.com
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----- Original Message -----
From: "Arun Bohm" <arun_bohm at hotmail.com>
To: <john.l.marshall at gte.net>; <synth-diy at dropmix.xs4all.nl>
Sent: Sunday, April 13, 2003 3:28 PM
Subject: Re: [sdiy] percusion synth design and problems.


> Thank you for responding so promptly. I am not sure about how close the
> station is I can barely make out the transmision so it can't have too much
> strength where I am at. What exactly would the power supply bypass be and
> where would I do the filtering. I have been told that putting a 1uf Cap
> across the power rails helps. is this filtering or bypassing. I think its
> filtering. What would I do to bypass. I will try grounding Unused
terminals
> tonight. Once again thank you. I really appreciate the advice. You and
> magnus and sometimes peasant are great help. I am just thankful for the
> list.
>
>
>
>
> >From: "John L Marshall" <john.l.marshall at gte.net>
> >To: "Arun Bohm" <arun_bohm at hotmail.com>, <synth-diy at dropmix.xs4all.nl>
> >Subject: Re: [sdiy] percusion synth design and problems.
> >Date: Sun, 13 Apr 2003 15:15:13 -0700
> >
> >The downside of wide bandwidth amplifiers. Solutions: proper shielding,
> >proper grounding, ground all unused inputs, additional power supply
> >bypassing, and low pass filtering.
> >
> >How close is the AM station to you?
> >
> >
> >Take care,
> >John
> >www.sound-photo.com
>
>
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