Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dude on December 08, 2020, 11:42:46 am
-
I'm thinking of putting one of my AO-43 Plexi 6v6 conversions in a combo cabinet. Locating the chassis just as the Marshall 1974 combo, 18 watt except the tubes will be horizontal. I plan to put a vent on the top a little wider than the 1974, with an open back. I didn't plan on using a fan for any cooling effect, the tubes would be inside an enclosed area but with say 2" wide vent all along the top.
Anyone foresee any issues with heat build up, or any suggestions?
-
As long as you have a decent size vent, it shouldn't be a problem.
-
"....the tubes would be inside an enclosed area but with say 2" wide vent all along the top."
-dude
IMO, 1" is enough.
2" don't need to be all along the top.
-
Is that the vent material (expanded metal) the chassis is on top of? I say make the vent any size you want and looks good in the cabinet.. still have to have room for a carry handle and that might be a factor.
Venting never hurts.
-
I say make the vent any size you want and looks good in the cabinet.. still have to have room for a carry handle and that might be a factor. Venting never hurts.
I have a Marshall 1974, the vent is about 1" wide, runs all along the top, never though about the handle. Since the weight will be mostly toward the back, I probably want the handle in the middle, so a 1" vent would be best for looks and carrying. My main concern was the 6V6's heat rising right below the cap cans, surely they would be much hotter than upright in a head cab. Could this heat on the cap cans cause premature failure?
-
My main concern was the 6V6's heat rising right below the cap cans, surely they would be much hotter than upright in a head cab. Could this heat on the cap cans cause premature failure?
With the top vented I would not be concerned.
-
most cap cans are temp rated for 85C, or 185 degrees F. Youre probably going to be fine with minimal venting as long as the normal spacing requirements for the tube were followed.
-
Thanks, I appreciate the advice. Just didn't want to make the cabinet to fit that chassis and run into issues.
Since, I talking about a Plexi 6V6 combo amp, of these speakers which would you recommend:
Weber 30 watt alnico blue, doped.
Celeston GH1230 (China)
Weber PR12, Signature Series
Red Fang, 30 watt, doped, alnico
None of the above but this ?
* I know tone is subjective but was just wondering what the vast majority think sounds best in these amps.
Right now I'm using the Celestion GH12 and the Blue Dog Weber, both 30 watts, but that's two 12's". The single,
I guess I'm thinking the Blue Dog, the GH12 get a little muddy alone, I guess I build the cab and try each... Just fishing here :icon_biggrin: .
-
WGS ET65 is my favorite speaker at the moment. I put a GH1230 in my AB763 blues jr and it sounded pretty damn good too.
-
most cap cans are temp rated for 85C, or 185 degrees F. Youre probably going to be fine with minimal venting as long as the normal spacing requirements for the tube were followed.
Yes, but if you run them at 10C cooler, then their life expectancy doubles. Drop it another 10C and the life expectancy doubles again. Approximately.
-
I'll just build the cab with the 1" vent, this amp is for a friends son who will be gigging with it when this pandemic is over. So, I'll feel the cans if too warm, I'll just drop a small fan in. I usually have any fan blowing away from the heat not toward the hot spots, drawing cooler air over the hot area.