muting circuit to eliminate turn-on thump

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Hi keilau,
You could use a voltage comparator driving a small relay. the comparator would have a pair of resistors on one input as a voltage divider and a resistor to Cap on the other input. The time to charge the cap and match the voltage on the divider can be varied by using a mulit-turn pot to slow the cap charging. If is much like the delay on a soft start circuit. If you need a schematic I can draw one up for you.
Have a good one.
 
Better to follow the process of turning on the preamp first then the power amp, and turning off the power amp first then the preamp. Just easier on the speakers.
I also prefer to have a delay connection on the input to the power amp, so the inputs are shorted until the amp is up and running, this protects the input circuit from spikes on cable connection and static problems. Just an idea.
 
Transcendent Sound sells a muting kit for preamplifiers.

>>>>>>Muting Circuit Mod

Recommended for Solid State Amps - $35

Here is a muting circuit that provides about a 15 second mute delay during turn-on for the Grounded Grid Preamp or any audio device that has 12 volts DC available. The circuit draws only 60 mA at 12 VDC allowing it to be installed in most any component. The circuit board is prewired. All that is required is to mount the board and terminal strip with three components and wire it up. The device does not interfere with the audio signal at all. Upon shut down, the mute function operates immediately thereby preventing any transients as circuits power down.<<<<<
 
Muting Circuit Mod

Transcendent Sound sells a muting kit for preamplifiers.

>>>>>>Muting Circuit Mod

Recommended for Solid State Amps - $35

Here is a muting circuit that provides about a 15 second mute delay during turn-on for the Grounded Grid Preamp or any audio device that has 12 volts DC available. The circuit draws only 60 mA at 12 VDC allowing it to be installed in most any component. The circuit board is prewired. All that is required is to mount the board and terminal strip with three components and wire it up. The device does not interfere with the audio signal at all. Upon shut down, the mute function operates immediately thereby preventing any transients as circuits power down.<<<<<
I went to browse the Transcendent Sound website but could not find the item you referred to. Can you provide a direct link? Much appreciated.

Your description sounds good. Can you post a schematic and the BOM?
 
I don't have the schematic and BOM. It is a kit so no blank boards as I recall. The board is mentioned in the text of the grounded grid pre-amp. I think you need to contact Bruce Rozenbilt directly to buy it separately. It used to be listed as its own separate product but in the website re-design that occurred over winter, the separate listing was removed.
 
Hope there is no copyright but i always use this circuit. Takes some tweaking of the resistor values for lower voltage. I now use this also with a 5V relay for like 20 seconds delay

Alos i have some Ebay sourced 555 based prints but have only tested these. Work fine on 12V but are single channel
 

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I have previously used a 555 timer for this purpose

Hope there is no copyright but i always use this circuit. Takes some tweaking of the resistor values for lower voltage. I now use this also with a 5V relay for like 20 seconds delay

Alos i have some Ebay sourced 555 based prints but have only tested these. Work fine on 12V but are single channel
I have fond memory of building 555 based delay turn-on published on The Audio Amateur (now AudioXpress) for my baby Ampzilla clone. It worked well in the 1970's. But now buying a UPC1237 based protection board on e-bay is cheaper and easier to manage. Functionally, they are all the same.
 

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Plinuis m8 pre amp lost remote control

I have a little understanding about electronics. I'm sorry I jumped in the muting circuit preamp section. I have a preamp that has a muting function that I can't use without a remote control. unfortunately, when we moved in to another place, I lost the original remote control of my preamp.

Can I ask for a suggestion where I can buy the original remote or a replacement universal remote control. Or is there a way to disable the muting without using the remote control.

pre amp function:
1.) when i turn on my preamp, the led display will blink for 5 seconds
2.) then you will hear a click sound and the led display will prompt CD mute.

My preamp has only a volume control.
 
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