Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: plexi50 on December 03, 2011, 03:32:30 pm
-
I replaced these same sockets 3 years ago in a Blues Junior. I can not get the tubes to release from the melted sockets. New tubes would be a good idea anyway at the looks of it.
-
Woah! Are those tubes biased hot!
-
No the bias was right. The person just leaves the amp on for days in a row because he forgets to shut it off. No standby switch. That was 3 years ago so i cant say how much on time it has on the tubes. Thats a lot of heat though
-
ceramic.
http://www.hoffmanamps.com/MyStore/perlshop.cgi (http://www.hoffmanamps.com/MyStore/perlshop.cgi)
garage wall trophies. i have bits and pieces of bike parts that didn't survive various wrecks: they are offerings to the gods of speed... yours would be offerings to the amp gods...
:icon_biggrin:
-
I replaced these same sockets 3 years ago in a Blues Junior. I can not get the tubes to release from the melted sockets. New tubes would be a good idea anyway at the looks of it.
:think1:
Wire up the 6.3v heater supply and let sit until the sockets are soft then try to remove them. :icon_biggrin:
I usually find myself doing the "more trouble than it's worth" kind of things.
j.
-
Good idea on the heat bigsbybender. I heated the pins up with a barbecue lighter and then pulled the pins off the tubes. Worked quick. One tube good ,One tube DOA
Yeah i will use ceramic sockets this time. I thought thats what i bought for this job back then. They were white
-
LOL. That's insane!
-
> just leaves the amp on for days in a row
Radio stations and computers left the tubes on 23/7.
I've never seen anything like that.
The rig needs better ventilation and ceramic sockets.
> I thought thats what i bought ... They were white
Use the blow-torch test.
I'd really want to drop B+ and raise cathode resistor; but I suppose the customer would whine about less loudness.
If this were a serious problem one could invent a time-out to stick another 1K of bias under the finals after 60 minutes of no-signal, with instant-on when signal happens again.
Or just put a fan in it. THAT will remind him to hit the power switch at bed-time.
-
When i first saw this yesterday i thought i was looking at Carmel Candy. It took me a few seconds to realize what i was looking at. Ive never seen sockets melt before. The customer is putting a fan in and i am double checking the sockets i buy this time
Im surprised that the tube plates are not disscolored
-
I have modified a few blues Jr. with a larger output transformer, Hammond 1750H and changed the output tubes to octal 7591. I suppose 6V6 would work also.