I have my breadboarded Aikido headphone amplifier playing music for some time now, and while it sounds fabulous it has a nasty habit of sending crackling noises through my headphones for about 30sec. after I switch it on...
The crackling/popping sets in after about 10secs and then completely stops after about 25-30secs. It is not rythmic but rather random so I don't think it is oscillation.
My Aikido is built with the Broskie boards, uses 6CG7 and 6H30 tubes, output transformers and a toroid psu with ss rectification and voltage doubler (to generate B+ out of a 2x55V toroid). Heaters are fed by a regulated supply.
Q. What can I do to get rid of the crackling noise on start up?
Q. Attached is a screenshot of my psu configuration. Anything wrong with that, like the value of the caps in the doubler (was thinking of putting much smaller film types in there...)?
Thank you as always!
The crackling/popping sets in after about 10secs and then completely stops after about 25-30secs. It is not rythmic but rather random so I don't think it is oscillation.
My Aikido is built with the Broskie boards, uses 6CG7 and 6H30 tubes, output transformers and a toroid psu with ss rectification and voltage doubler (to generate B+ out of a 2x55V toroid). Heaters are fed by a regulated supply.
Q. What can I do to get rid of the crackling noise on start up?
Q. Attached is a screenshot of my psu configuration. Anything wrong with that, like the value of the caps in the doubler (was thinking of putting much smaller film types in there...)?
Thank you as always!
Attachments
I'm not an expert here and I'm sure you'll get good advice but I'm thinking if you have SS power supply this crackling could be the B+ power surge going through the tubes before they have warmed up sufficiently.
I have 2 tranny and 2 switches. I switch on the heaters first for a good 30 seconds before hitting the B+.
I have 2 tranny and 2 switches. I switch on the heaters first for a good 30 seconds before hitting the B+.
My recently (almost) completed Aikido has some small crackling/popping and a slight DC offset for the first 5 seconds or so of warm-up.
I recently added this power on mute circuit (simple and adjustable from a few seconds to 30+ seconds) and so far it works like the cat's pajama's.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=58043&highlight=preamp+muting
Nothing added to the sig path, it just shorts the preamp outputs for however many seconds you want depending on the setting of the trim pot. I'm actually shorting the outputs through 150 ohm R's.
I recently added this power on mute circuit (simple and adjustable from a few seconds to 30+ seconds) and so far it works like the cat's pajama's.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=58043&highlight=preamp+muting
Nothing added to the sig path, it just shorts the preamp outputs for however many seconds you want depending on the setting of the trim pot. I'm actually shorting the outputs through 150 ohm R's.
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