Vibrations / buzz on low notes, help !!

Discussion - HT-5 amplifiers.
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Posts: 5
Joined: Thu Nov 26, 2015 9:59 am

Thu Nov 26, 2015 10:35 am

Hi Blackstar community,

I'm the recent owner of an HT5R. This amplify is really great but after a few minutes of use, I hear some vibrations both on clean and OD channel coming from the loudspeaker.
This vibration sound/buzz only appears when I play certain low notes.
I've tried with many guitars or cables and the problem is still here.
When I play with headphones, the buzz does not appear. It seems that the loudspeaker makes something vibrate in the combo...
Is there anything special I can do to resolve this problem ?
After searching the internet , I noticed that the tubes could be the reason. I have changed the preamp tube by a new one and the problem is still here.

Do you think I should change the power tube too (12BH7)?
Many thanks for your answers/advices !

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Posts: 617
Joined: Thu Feb 24, 2011 1:00 am

Fri Nov 27, 2015 12:42 am

Check the cabinet to see if it is a resonant frequency and/or anything is loose. If it is a speaker issue, check to see if the speaker is too loose or too tight (tweaked/bent frame). The speaker should be snug, but neither extreme. Also, there is the possibility of a voice coil rub issue. Listen to a youtube example to see if that's what you are hearing. Good luck.

Posts: 5
Joined: Thu Nov 26, 2015 9:59 am

Fri Nov 27, 2015 10:30 am

Thanks for your answer.
I will check the speaker... I don't think it is a voice coil rub issue. The sound is quite different....
I have asked Blackstar but I still wait their answer.
Thanks !

Posts: 1
Joined: Wed Nov 20, 2019 9:17 am

Wed Nov 20, 2019 9:29 am

Same issue here. Did you fix it?

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