Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Bdimb on January 27, 2014, 02:08:14 pm
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This short cell phone video shows the symptom fairly well.
Hoffman 5E3, Hammond 272BX PT, newish tubes. Only mods are the coupling cap de-fart.
I knew there would be down time at work today and I planned on some troubleshooting time today but DVM has been absconded with. Wanted to post some data as well, but figured I would toss this out in the mean time.
IMG 2708 (http://www.youtube.com/watch?v=_rptYpRCL0Q#ws)
If you look thru my channel, there is another lo fi video of the amp being played without the sizzle.
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Have you tried an other speaker ??
I had this happened to me with a brand new Celestion Heritage Greenback...
It's probably cone rub / or something in the magnet gap. It was the exact
same noise, low volume, like yours... If it's really the case, there is nothing
you can do except recone...
Good luck !!
Philippe
Oups, I just saw the end of your video with the other sparker :embarrassed:
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Phillipe
Don't be sorry, every suggestion helps. So, in full disclosure, it's a used Weber; it may have been abused/misused. The only other speaker I have here at work is a Peavey 10" 6ohm and it exhibits similar (but not exactly the same) characteristics. I will be trying yet another speaker tomorrow to try and eliminate it as root cause.
Here it was last summer when I tried to sell it, no such bad sound (other than my playing!) Skip the blah blah blah and go to 2:15.
IMG 2133 (http://www.youtube.com/watch?v=3jVRiGdxrB0#)
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As Philippe accurately predicted, it's the speaker. Good reminder to me to keep an open mind when trouble shooting; the amp gets very little play time and is always at moderate levels. Since it was OK last time I played it, I jumped to the conclusion that is was something electrical that had gone out of spec.
Fast forward to yesterday, and Murphy's law states that I have to use another CRAP speaker to test with...
Lesson learned.