This is my first post to this forum. I'm relatively new to desiging electronics. I'm building an analog cross-over using
BB opa2134 chips.
The buffer stage is powered by my own power supply: Toroidal transformer 2 x 18 V windngs -> +/- 28 V. The voltage measures ok. Then I use a 7815-7915 Voltage regulators to get +/- 15 V. This meaure +/- 15.1 V. I use 2 x 3300 uF (35 V) before the regulator and 2 x 33uF (50V) after the regulator. All legs of the regulators have in addition 2.2uF Tantalums.
I get amplification but when there's a
signal there's a distortion sound on the
signal. It sounds like dust on a vinyl
record and is only present when there's a signal. It is caused when I connect the power ground to source ground. But if I float the source ground there's a loud hum. If I substitute 2 x 9 V batteries the crackling goes away.
My question is what am I doing wrong? Any suggestions on how to troubleshoot and or fix? Pleaase be patient with me as I'm relatively new to this part of the game.
Thanks in advance
Harry Andree
BB opa2134 chips.
The buffer stage is powered by my own power supply: Toroidal transformer 2 x 18 V windngs -> +/- 28 V. The voltage measures ok. Then I use a 7815-7915 Voltage regulators to get +/- 15 V. This meaure +/- 15.1 V. I use 2 x 3300 uF (35 V) before the regulator and 2 x 33uF (50V) after the regulator. All legs of the regulators have in addition 2.2uF Tantalums.
I get amplification but when there's a
signal there's a distortion sound on the
signal. It sounds like dust on a vinyl
record and is only present when there's a signal. It is caused when I connect the power ground to source ground. But if I float the source ground there's a loud hum. If I substitute 2 x 9 V batteries the crackling goes away.
My question is what am I doing wrong? Any suggestions on how to troubleshoot and or fix? Pleaase be patient with me as I'm relatively new to this part of the game.
Thanks in advance
Harry Andree