trinityamps.com

Hi all! New here, hoping to get some advice. I purchased this Trinity tweed second hand through the Canadian Guitar Forum - it is the very one used in the demo video on the Trinity site (though it now has a different speaker). I'm not well versed in amp technology, which is why I bought a complete amp instead of a kit. Now, onto my issue. When I crank the amp, after playing then muting the guitar, the power tubes continue to "pulsate" back and forth, with very noticeable sound coming from the amp - almost like a tremolo effect. You can see the tubes glowing back and forth. Here's a video I just posted to YouTube, but note the sound is much louder than what appears in the video. You can even see the glow of the tubes bouncing back and forth (hence the dark video). Can someone explain what is going on here, and any ideas as to what may correct it?

Thanks in advance!

http://youtu.be/v3ichnZrRYI

Do you have any thing else plugged in other than the guitar ie effect board pedals that sort of thing ?

If so plug guitar in by itself. see if you still have the issue and as you say you have it cranked up at this point once you have it oscillating un plug the guitar from the input of the amp and see if it continues

If so could be as easy as a bad tube . From your post your not techy and I do not know if you have any spares around swapping tubes is not that hard but you have to turn the amp off and unplug it from the wall before doing so!

Thanks for the quick reply. I am plugged straight into the amp. I've tried rolling back the guitar volume (the pulsing continues), but never thought of unplugging completely - I'll give that a shot when I get the chance.

I'm also technically inclined, I just don't have any background in amp circuit design. I don't have a problem changing a tube, but I don't have any spares at the moment. I'll get some...

Boy, I have never seen that!! If it werent a problem, it would be very cool!
Yes, my first thought would be tubes, and go from there. But, maybe contact the seller too.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

This just happened on a Tramp with an old 6V6 tube installed. I replaced the tube with a new Tung-Sol and the problem went away.
So, I suggest you replace the power tubes or one of them at a time.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps

^ Thanks - will do!

Figured I'd follow up after having my tech give the amp a once over. He did indeed find a bad tube, but also a filter cap had become disconnected somehow, and to top it off there was an issue with the input jack connection which was causing some noise.

Thanks for the info!

Thanks for the info. Good troubleshooting info. I'm pretty sure the pulsing was caused by the bad tube.

_________________
Stephen
Web: www.trinityamps.com. Facebook: facebook.com/trinityamps. Twitter: @trinityamps