Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dynaman1 on December 14, 2010, 11:32:25 am

Title: Proximity of output tubes to speaker magnet
Post by: dynaman1 on December 14, 2010, 11:32:25 am

Reworking a small combo amp. I'd like to horizontally mount a quad of 6V6s and a couple of them will wind up having the bottom edge of their glass about 1" directly above the magnet ring. Too close??

Please and thanks.

Title: Re: Proximity of output tubes to speaker magnet
Post by: Willabe on December 14, 2010, 12:41:49 pm

Hi dynaman,

I did a 5E3 build (my 1st)  and built the cab myself, and its the same size as the 5E3 I copied. I had an alnico type speaker (small mag.) in it. Didnt like the sound of it, no bottom end, OK fine, I'll just change it. I got a different speaker, this time with a much bigger mag. (ceramic), put it in, fired it up, sounded bad, no vol. ect. :sad: Looked in the back and one of the 6V6's had lite up just like a light bulb,   :icon_scratch:  what the.... :huh:   :dontknow:  Shut it down, made a call to the company I bought the new speaker from, the Man says "the speaker mag. is too close to the tube".   :rolleyes:   OK, so what should I do? Man say's "make a new speaker baffle, change where the speaker cut out is in the baffle, move it away from the tube". OK, so I made the new speaker baffle, with the speaker moved away from the "light bulb" tube, works fine to this day, end of story.   :laugh:   

So yes, might be a problem. Can you change the baffle,move the speaker? If your careful you can reuse the same grill cloth to keep the same look.

     
    Brad        :smiley: