Showing 1 of 959 conversations about:
Kosior
117
Nov 4, 2018
bookmark_border
I would buy one if it weren't a fire hazard. My cat's too curious to own one of these. That tube can light a fire if left unattended.
Nov 4, 2018
Dr.Tyler
148
Nov 4, 2018
bookmark_border
Tubes don't spontaneously combust. This thing is heavy. I doubt your cat would do anything other than burn itself. With the exception of an initial tube burn-in phase, I don't know why anyone would leave it on when they're not using it.
Nov 4, 2018
ohsigmachi
222
Nov 4, 2018
bookmark_border
This is just absolutely not true. If you, covered the amp in a easily combustible material, and left it on for a few hours... maybe. I've had mine on for 6 hours many, many times (and I "gasp" walked away and left it unattended for long stretches), no fires.
Nov 4, 2018
mikeonline
93
Nov 6, 2018
bookmark_border
I'll echo the previous sentiments. I've had mine on all day on multiple occasions, and it's been fine. Furthermore, many valve tubes are made of pretty durable glass, some NOS tubes were even made for military use. They're not gonna break by tapping on it or anything. If your worried about a fire just turn it on when you use it. The whole "tubes need a warm up before use thing" is blown way over proportion imo. 15min max and your fine.
Nov 6, 2018
Kosior
117
Nov 6, 2018
bookmark_border
I don't want my cat to get burnt in the first place. He's nosy, and will get into it while i'm using it. I'm not implying that i'll leave it on, I just have a demon pet who will definitely set my apartment on fire or at the least get hurt if I own one of these. Not implying that the tubes are dangerous in good hands. I just have bad paws in my casa and can't risk anything hot out in the open.
Nov 6, 2018
pukkita
20
Nov 7, 2018
bookmark_border
> The whole "tubes need a warm up before use thing" is blown way over proportion imo. 15min max and your fine. It depends. Tubes work by the thermoionic effect, and specially NOS tubes (or new production ones not pre-burnt in) need a burn-in period so that the tube degasses and completes its vacuum, reaching their optimal operating conditions. https://www.eham.net/ehamforum/smf/index.php?action=printpage;topic=5207.0 Don't forget the output stage 6N5PJ/6AS7A is a power tube conceived for series pass DC PSU regulation, hence the hefty filament supply (2,5A if I recall well) and heat generation. That's the reason for burn-in removing the 6SN7, to allow the 6N5PJ to get to its optimal conditions before high DC voltage is applied on its plates (removing the 6N5PJ cuts the voltage going to the 6SN7), which could potentially harm tube performance afterwards. Once that initial burn-in has been done, amp just requires minutes like you said to be ready.
(Edited)
Nov 7, 2018
mikeonline
93
Nov 7, 2018
bookmark_border
Whoa that's really interesting! Don't want to get too off topic, but do you know if this is related to humming/buzzing found in tubes sometimes?
Nov 7, 2018
pukkita
20
Nov 7, 2018
bookmark_border
Yes, most times. If after a reasonable time the hum or buzz is not gone, the tube is a lemon...
Nov 7, 2018
View Full Discussion