Trinity SIII strange trouble

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Davidbob
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Posts: 4
Joined: Sun 08/16/20 9:31 am

Trinity SIII strange trouble

Post by Davidbob »

Hello, first, excuse my poor english.
I just finish to build a trinity 18w SIII head and a 212 cabinet. This i my third build, and i have play a week long with this 18w, great sounding amp. But tonight, i was to play with it, all was fine, dead quiet, no strange noise. I have unplug the guitar cable at the amp to change guitar from my lespaul to my strat.
And sudently, a strange noise coming from my speaker, like a low frequency sound..
So i plug back my guitar and... Nothing, no sound from my guitar, i taise the amp and guitar volume, nothing. Can't play anymore.
But the strange sound was ther.
So i put the amp on stanby, and the sound disapear. Wait for a minut or two and switck back on, and now all was good, the amp came back alive....
Do you have an idea!
Is it possible that the output transfo was bad, but intermitently?
๐Ÿ™„๐Ÿ™„๐Ÿ™„๐Ÿ™„
Thank's

David
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Daviedawg
Superior Amp Tech
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Posts: 748
Joined: Fri 01/08/10 2:00 am
Location: Scotland

Re: Trinity SIII strange trouble

Post by Daviedawg »

An intermittent problem on a new build is much more likely to be a poor connection than anything else. Heat makes the connection move. Not guaranteed to be the answer but we are limited by working at a distance like this. It is where I would start.
If it affects both channels or just one channel then you can start to refine where you start looking. e.g if only one channel then look at the preamp stage for that channel. Be methodical. With the amp off start visually examining and tracing the build against your schematic and layout and mark them up as you go. Use a magnifier. Look for "whiskers" at joints that could be shorting. Check component values while there as it might save time later. Then move to chopsticking components and joints looking for noises with the amp running.
If you still have an issue after that take some pics and post them and the schematic and layout for us to provide more detailed help.

Good luck.

Dd
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Davidbob
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Posts: 4
Joined: Sun 08/16/20 9:31 am

Re: Trinity SIII strange trouble

Post by Davidbob »

Ok thank you, i will pll the chassis out today.
This little amp put out lot of heat!!!
After 20 minutes of playing, the metal mesh on the vent hole on top of the head was very hot to the touch.
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