I have been experimenting with a vibrato circuit which uses varistors using the circuit in Stompboxology vol. 5 No. 1 (figure 2 page 3) http://moosapotamus.net/files/stompboxology-vibrato-rama.pdf (http://moosapotamus.net/files/stompboxology-vibrato-rama.pdf) It uses a bipolar power supply. The problem is, despite using bypass capacitors and small value resistors to isolate voltage to the different parts of the circuit, I cannot get rid of the LFO thump. I wanted to try integrating an NE570 compander which is rated up to a maximum 24 volts. My bipolar supply is +12/-12 v. I wanted advice on how to connect the ground connections for the NE570. I assume +12v goes to vcc on the compander and -12v goes to power ground. Should links to ground through capacitors etc. go to bipolar ground (0 volts), or to -12v?
The vibrato I am getting is nice, if only I could get rid of the thump
Can't open your attachement but the general idea is ALL capacitors should have one leg linked to GND (0 Volts DC or AC..)
(exception for decoupling bi-polar supply caps where you can link both to GND or replace them with a single cap between + & - (Vcc & Vee).
Quote from: antonis on February 07, 2019, 12:08:20 PM
Can't open your attachement but the general idea is ALL capacitors should have one leg linked to GND (0 Volts DC or AC..)
(exception for decoupling bi-polar supply caps where you can link both to GND or replace them with a single cap between + & - (Vcc & Vee).
Not ALL capacitors. Series capacitors are excepted obviously.
Quote from: Yazoo on February 07, 2019, 11:27:12 AM
I wanted advice on how to connect the ground connections for the NE570. I assume +12v goes to vcc on the compander and -12v goes to power ground.
I could be wrong, but I don't think you can run the NE570 from a bi-polar supply using Vcc and GND. The datasheet states "intended for use in single power supply systems" so I think you can only run it using +12V and GND.
I'm not sure how much of the original circuit you made, but note IC1 forming a power rail splitter for connection "B". To convert to bi-polar, IC1 isn't needed and "B" becomes ground.
Quote from: GGBB on February 07, 2019, 08:20:27 PM
Quote from: antonis on February 07, 2019, 12:08:20 PM
Can't open your attachement but the general idea is ALL capacitors should have one leg linked to GND (0 Volts DC or AC..)
(exception for decoupling bi-polar supply caps where you can link both to GND or replace them with a single cap between + & - (Vcc & Vee).
Not ALL capacitors. Series capacitors are excepted obviously.
:icon_biggrin: :icon_smile: :icon_lol: :icon_smile: :icon_lol:
(one leg grounded capacitor can't considered "series" anymore, can it Gord..??)
Quote from: antonis on February 08, 2019, 06:02:30 AM
:icon_biggrin: :icon_smile: :icon_lol: :icon_smile: :icon_lol:
(one leg grounded capacitor can't considered "series" anymore, can it Gord..??)
[/quote]
No it can't, just like it can't be considered "ALL" :)