Post by sumgai on May 12, 2006 2:33:42 GMT -5
I can just hear it now......
Leader: "People, let's all welcome our newest member, LTT. LTT, will you please come up to the podium?"
LTT: "Hi, my name is LTT, and I have GAS, so thanks for letting me attend this GBA meeting!" (Guitar Buyers Anonymous)
ltt,
You're right, we've discussed this at various times, and there are many other sites on the innerweb that deal with the topic, too. To sort of re-hash it, I'll try to condense it down to one or two paragraphs.
In a nutshell, yes you can pull one of the speakers, but the risk of damage is low - at first. How long can you run like that? For awhile. How long is that? Depends. On what? On how loud things get. Is there a guideline? Not a hard and fast one, but FWIW, here's how I see it. As an emergency, no sweat. Speaker pops on the third song of the first set, just pull it, and play for the rest of the night. If you played at full volume, that's it, you're done. Any more, and you're risking the remaining speaker(s).
If you were just poking around in the bedroom, not too loud, then you can probably go for 30 to 60 days without any damage, and maybe even longer. Somewhere in there is a gray area that is up to you. Personally, I'd not risk having to buy a second speaker when I already have to replace one as it is. All this applies to your situation as if you'd blown one speaker, take it from there.
No, you can't pull any transformers, plain and simple. Sorry, but that's just the way they built 'em.
Also, you "can" pull one of the output tubes, but that way lies folly in the extreme. It may even sound good, for awhile, but you're risking the output transformer, the remaining tube, and possibly the power supply section. This also changes the output impedance to the speaker, in the opposite direction of the above, making that paragraph moot (the disparity is too large). My final answer, Regis, is - don't do it. 
You can, however, put the one or both speakers into a smaller cabinet, and put the head into its own cabinet. Just a few days of labor in the woodshop, and you're all set. (Yeah, right!)
Final thought. Find a local tech who knows his butt from a hole in the wall. Ask him to insert a 50 or 60 volt zener diode in the center leg of the power transformer (show him this request, if that helps). The reason being, this will drop the B+ (the main power supply output to the tubes) by the specified amount. Why do that? Because you're about to install a set of 6V6's, and they have a lower B+ requirement. These tubes'll deliver only about half the power to the speakers, maybe even less than that. But if you stick the 6V6's in without dropping the B+ way down, then you'll make those new bottles go up in flames, post haste and mosh-kosh! Expensive fireworks, that.
Come to think of it, putting the speakers in a separate cabinet that's been nicely finished, that just might fetch some cash on eBay (or craigslist). Ditto for the amp chassis, that has possibilities too.
sumgai
Leader: "People, let's all welcome our newest member, LTT. LTT, will you please come up to the podium?"
LTT: "Hi, my name is LTT, and I have GAS, so thanks for letting me attend this GBA meeting!" (Guitar Buyers Anonymous)
ltt,
You're right, we've discussed this at various times, and there are many other sites on the innerweb that deal with the topic, too. To sort of re-hash it, I'll try to condense it down to one or two paragraphs.
In a nutshell, yes you can pull one of the speakers, but the risk of damage is low - at first. How long can you run like that? For awhile. How long is that? Depends. On what? On how loud things get. Is there a guideline? Not a hard and fast one, but FWIW, here's how I see it. As an emergency, no sweat. Speaker pops on the third song of the first set, just pull it, and play for the rest of the night. If you played at full volume, that's it, you're done. Any more, and you're risking the remaining speaker(s).
If you were just poking around in the bedroom, not too loud, then you can probably go for 30 to 60 days without any damage, and maybe even longer. Somewhere in there is a gray area that is up to you. Personally, I'd not risk having to buy a second speaker when I already have to replace one as it is. All this applies to your situation as if you'd blown one speaker, take it from there.
No, you can't pull any transformers, plain and simple. Sorry, but that's just the way they built 'em.
Also, you "can" pull one of the output tubes, but that way lies folly in the extreme. It may even sound good, for awhile, but you're risking the output transformer, the remaining tube, and possibly the power supply section. This also changes the output impedance to the speaker, in the opposite direction of the above, making that paragraph moot (the disparity is too large). My final answer, Regis, is - don't do it. 
You can, however, put the one or both speakers into a smaller cabinet, and put the head into its own cabinet. Just a few days of labor in the woodshop, and you're all set. (Yeah, right!)
Final thought. Find a local tech who knows his butt from a hole in the wall. Ask him to insert a 50 or 60 volt zener diode in the center leg of the power transformer (show him this request, if that helps). The reason being, this will drop the B+ (the main power supply output to the tubes) by the specified amount. Why do that? Because you're about to install a set of 6V6's, and they have a lower B+ requirement. These tubes'll deliver only about half the power to the speakers, maybe even less than that. But if you stick the 6V6's in without dropping the B+ way down, then you'll make those new bottles go up in flames, post haste and mosh-kosh! Expensive fireworks, that.
Come to think of it, putting the speakers in a separate cabinet that's been nicely finished, that just might fetch some cash on eBay (or craigslist). Ditto for the amp chassis, that has possibilities too.
sumgai
