Help with big click-pop during relays switching!!!

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dukasound

Well-known member
Joined
Jun 4, 2004
Messages
711
Location
Kotor, Montenegro
Hi
I am finishing one guitar tube preamp based on my old preamps of my amplifiers (maybe with adding one tube).
Duka_preamp.GIF

Like on old I have big click-pop when I switch relays. What to do?
I read about 4M7 to 10M throught relays contact. Where to add resistors?
Also I have 12VDC for relays. Is it possible to use two 6V relays in series. I ask maybe there is a chanse to have some delay in switching.
Thanks in advance
Duka
 
Add your 4.7M or 10M "tie down" resistor from the .022uF coupling cap of V1A to ground, and also from the left-hand side of the 0.1uF coupling cap (at the far right side of the schematic) to ground. And make sure that the relay coil is shunted by a reverse-biased diode.
http://www.kpsec.freeuk.com/images/diopro.gif
 
[quote author="NewYorkDave"]Add your 4.7M or 10M "tie down" resistor from the .022uF coupling cap of V1A to ground, and also from the left-hand side of the 0.1uF coupling cap (at the far right side of the schematic) to ground. And make sure that the relay coil is shunted by a reverse-biased diode.
http://www.kpsec.freeuk.com/images/diopro.gif[/quote]
I put 1N4148 diodes on relays.
Is it mean to put resistors on all relays on middle point?
Duka_preamp2.GIF

What with other relays?
Thanks for reply
 
[quote author="NewYorkDave"]Oh, I overlooked the .022 coupling cap on V1B. Add a tie-down resistor there as well.[/quote]
Bad english :?
On right hand of V2B 0,022uF?
Like this
Duka_preamp2.GIF

And what with other contact? No need :?:
 
Hi,
The idea is to keep the coupling caps charged at the same DC for both relay positions, which is done with the resistors connected to the ground. IMO, resistors at Re1 and Re3 aren't needed, just at Re2. Of course, you don't need resistors at all relay contacts.

Regards,
Milan
 

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