Forums
New posts
Search forums
What's new
New posts
New profile posts
Latest activity
Members
Current visitors
New profile posts
Search profile posts
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Modular Amps
Synergy Amps & Modules
Mr Scary ringing sound
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Help Support Synergy/MTS Forum:
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Message
<blockquote data-quote="kc2eeb" data-source="post: 27887" data-attributes="member: 811"><p>What you're describing is micro-phonic feedback. When you have a very high gain circuit, and a susceptible tube, you get what amounts to feedback like you get from a microphone through a speaker. It builds in intensity for the same reason feedback from a microphone builds in intensity; it's getting re-amplified. The tube acts like a microphone. The reason I mentioned the fan is that a tube can pick up the physical vibration from the fan. If the tube nearest the input jack is making noise when you tap it, remember that is being amplified by the gain factor of each stage of the amp, 10x10x10, etc. I changed the three 12ax7s on the chassis, selecting them as, the one nearest the input jack for low noise, the one nearest the output tubes for balanced triodes, and the effects loop also for low noise. Hope this helps! Pat L.</p></blockquote><p></p>
[QUOTE="kc2eeb, post: 27887, member: 811"] What you're describing is micro-phonic feedback. When you have a very high gain circuit, and a susceptible tube, you get what amounts to feedback like you get from a microphone through a speaker. It builds in intensity for the same reason feedback from a microphone builds in intensity; it's getting re-amplified. The tube acts like a microphone. The reason I mentioned the fan is that a tube can pick up the physical vibration from the fan. If the tube nearest the input jack is making noise when you tap it, remember that is being amplified by the gain factor of each stage of the amp, 10x10x10, etc. I changed the three 12ax7s on the chassis, selecting them as, the one nearest the input jack for low noise, the one nearest the output tubes for balanced triodes, and the effects loop also for low noise. Hope this helps! Pat L. [/QUOTE]
Verification
Post reply
Modular Amps
Synergy Amps & Modules
Mr Scary ringing sound
Top