My amp, the Low TIM, assembled with the Lightspeed attenuator was making a loud thump when the changeover relay for input selector was operating. The relay has 4 changeover contacts. I used it for selecting two inputs. I have many other relays but nothing to compete with this one's contact quality. It is siemens make and the contacts are still shining, after so many years.
So, I designed a logic that would cycle through mute-relay operation-unmute on input select signal and connected this to the lightspeed attenuator.
Now there is no thump issue. The process is slow and amp goes silent during its period.
I also designed the speaker relay contact spark inhibition as an additional feature.
The block diagram goes like this
edge detector---multiple pulse generator---driver---relay
Gajanan Phadte
So, I designed a logic that would cycle through mute-relay operation-unmute on input select signal and connected this to the lightspeed attenuator.
Now there is no thump issue. The process is slow and amp goes silent during its period.
I also designed the speaker relay contact spark inhibition as an additional feature.
The block diagram goes like this
edge detector---multiple pulse generator---driver---relay
Gajanan Phadte
then ...its simple as that you need to find out if the thumb is relay related or source related ....
simple as that remove the plastic cover of the relay in order to be able to push the contacts to change source by hand with no actual power .... if you don't get any thumb means that the thumb is related to the power supply or configuration of the coil /relay
if you do get a thumb it means that excessive DC exists in your sources coming from any reason
check that and get back to us
kind regards sakis
simple as that remove the plastic cover of the relay in order to be able to push the contacts to change source by hand with no actual power .... if you don't get any thumb means that the thumb is related to the power supply or configuration of the coil /relay
if you do get a thumb it means that excessive DC exists in your sources coming from any reason
check that and get back to us
kind regards sakis
in this case there is a very good chance that your amplifier and the way is implemented might "pick up " noises due to ground or chassis configuration
possible options is the rooting of RCA input ground and /or choice of ground lift or not
that will be the option to have the star ground of the power supply connected to the chassis or not
one other option can be to in a way terminate the input of your system with 47K to ground to see if this is going to change things for better or worst
also some pictures of your make might help
possible options is the rooting of RCA input ground and /or choice of ground lift or not
that will be the option to have the star ground of the power supply connected to the chassis or not
one other option can be to in a way terminate the input of your system with 47K to ground to see if this is going to change things for better or worst
also some pictures of your make might help
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