Normal CHannel Microphonic

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Hebaton
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Normal CHannel Microphonic

Post by Hebaton »

MY just completed GDS 18watt has a microphonic normal channel.
Is that to be expected or do I have an issue ? Seems to me I hear some "dirt" ( not in a good sense ) in there where the tremolo channel is a lot quieter...
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JMPGuitars
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Re: Normal CHannel Microphonic

Post by JMPGuitars »

Why do you say microphonic? Microphonic is a pretty specific behavior, and not generally described as weird dirt.

I'd suggest recording both channels unplayed with an instrument plugged in, then strum some chords, and let us hear what you're hearing.

Thanks,
Josh
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Hebaton
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Re: Normal CHannel Microphonic

Post by Hebaton »

I say microphopnic because it is. Simply. When the normal channel volume is turned up, tapping on th top of the chassis is heard trough the speaker weather there is something pluged in or not. It is microphonic, I know what this means. That channel is also noisy where the tremolo channel is quiet.

I'm not equiped to record other than from a cheap phone. But the fact is that the normal channel has that behaviour the other does not. Changing V1 does not make a difference so I am assumimng it is not the tube ...
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Re: Normal CHannel Microphonic

Post by JMPGuitars »

Okay, thanks for clarifying that (your phrasing to me sounded like the dirt was part of what you were calling microphonic).

Anyway, post your voltages using the appropriate chart from the downloads section so we can see what's going on.

Thanks,
Josh
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Daviedawg
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Re: Normal CHannel Microphonic

Post by Daviedawg »

Sometimes you can get microphonic effects from duff capacitors. I say duff because they read and work as specced but make noise if tapped or moved. It is also possible for bad joints to reverberate. That would also explain noise in the channel. Chopsticking soon reveals where in the circuit the noise is being generated.

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