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Post by DonaldDemon on Mar 12, 2010 9:41:46 GMT -5
My volume has been dipping up and down lately and the volume level just isn’t there. I have actually been running the master volume at 11:00 just to be heard and I KNOW that’s not right. That should be rattling windows at that level!
I probably haven’t changed them in a year now so I guess it’s time. I have a 3-set all night gig next Friday and I’m a little worried the amp is going to crap out and blow a fuse or something. Does that normally happen when tubes start to die and the volume dips? I’ve never blown out a tube so I don’t know.
I would get new tubes before the gig but I can’t afford them + the biasing from a tech so I have to be able to make it through the gig. This might be the first time I bring my Rivera as a back up!
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Post by philm on Mar 12, 2010 10:40:22 GMT -5
I had this exact thing happen with my Quickrod last year--I waited too long to replace the Mullards. First the volume thing, it also got a little harsh sounding. Blew a fuse at rehearsal, replaced it and got another couple of hours out of it before blowing it again. Finally took it in and retubed with Svetlanas and it sounded like GOD when I got it back. When the tubes went bad, they faded so gradually--it wasn't like the amp just sounded like sh!t one day.
Usually not all the tubes are bad at exactly the same time. If you can figure out which are closest to being on the way out, maybe you can run two tubes for half power. Your tech can tell you this information and it will be far cheaper than retubing.
Tubes have gotten mad expensive, KT88s/6550s even more so. Looks like you're in for $120-$130 for tubes alone. If you're not getting new tubes, bring the back-up amp. In fact, based on my experience above, I'd use the Rivera for the show.
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Post by splatter on Mar 12, 2010 11:41:19 GMT -5
I had this exact thing happen with my Quickrod last year--I waited too long to replace the Mullards. First the volume thing, it also got a little harsh sounding. Blew a fuse at rehearsal, replaced it and got another couple of hours out of it before blowing it again. Finally took it in and retubed with Svetlanas and it sounded like GOD when I got it back. When the tubes went bad, they faded so gradually--it wasn't like the amp just sounded like sh!t one day. Usually not all the tubes are bad at exactly the same time. If you can figure out which are closest to being on the way out, maybe you can run two tubes for half power. Your tech can tell you this information and it will be far cheaper than retubing. Tubes have gotten mad expensive, KT88s/6550s even more so. Looks like you're in for $120-$130 for tubes alone. If you're not getting new tubes, bring the back-up amp. In fact, based on my experience above, I'd use the Rivera for the show. +1 I would advise using the rivera as well unless you can isolate which tube-tubes are shot.Even if it does make it thru the gig your volume is probably not going to be consitant for an all 3 sets . |
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Post by DonaldDemon on Mar 12, 2010 16:55:35 GMT -5
Crap, that’s what I was afraid of hearing. The only problem is the tubes on the Rivera are even older, lol! Plus my sound is set up for the Pro Mod, not the Rivera though I guess it’s better than having an amp that doesn’t work at all. I will definitely bring it as a back up if I don’t get the tubes changed. Maybe I will bite the bullet and put the tubes on my credit card. There’s no guarantee the tech can get it done on time though. I really need to learn how to do this myself.
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Post by greglecompte on Mar 13, 2010 12:44:28 GMT -5
if you get the same tubes with same rating you shouldn't half to re bias
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Post by sasquatch on Mar 13, 2010 12:49:05 GMT -5
Crap, that’s what I was afraid of hearing. The only problem is the tubes on the Rivera are even older, lol! Plus my sound is set up for the Pro Mod, not the Rivera though I guess it’s better than having an amp that doesn’t work at all. I will definitely bring it as a back up if I don’t get the tubes changed. Maybe I will bite the bullet and put the tubes on my credit card. There’s no guarantee the tech can get it done on time though. I really need to learn how to do this myself. I just bought a quad of Sino's from Scott for about $80.00. Tested, matched and marked. You've probably already done the gig, but if you know what the ratings are on the tubes currently in the amp, you can order a set or quad from Scott with the same ratings. This would allow you to install the tubes and play the gig, then you could have your tech do the bias afterward. Hope all goes well! |
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Post by DonaldDemon on Mar 13, 2010 15:39:50 GMT -5
The gig is actually next Friday. Unfortunately I didn't get the tubes from Scott and have no clue what the ratings are. I think I might just buy a new set and hope it makes it to my house by early next week.
Any one know what each preamp tube slot controls on the 3-pre versions. I take it V1 is the clean and first gain stage and v3 is the phase invertor?
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Post by philm on Mar 15, 2010 7:43:50 GMT -5
Wow, what are sinos? A quad for $80? I looked on Doug's Tubes site and it looked like the 6550s were all big bucks. Most of the KT88s were less ... DD, stick with what you know. Those Tung Sol 6550s have been working for you for awhile now.
It sucks that you don't think you'll be able to get this fixed before your show. I think I'd pony up and do the credit card thing ... or plan to use the Rivera.
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Post by DonaldDemon on Mar 15, 2010 16:32:15 GMT -5
Wow, what are sinos? A quad for $80? I looked on Doug's Tubes site and it looked like the 6550s were all big bucks. Most of the KT88s were less ... DD, stick with what you know. Those Tung Sol 6550s have been working for you for awhile now. It sucks that you don't think you'll be able to get this fixed before your show. I think I'd pony up and do the credit card thing ... or plan to use the Rivera. Yep, I sadly busted out the credit card. $187 in new tubes.....OUCHHHHHHHHH. I had to stick with the Tung Sols because I am happy with the tones. I also ordered a bias probe from eurotubes to bias the amp myself. Hopefully the stuff arrives in time and I can figure out how to bias my amp in a few hours, LOL! |
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Post by sasquatch on Mar 15, 2010 17:08:27 GMT -5
Wow, what are sinos? A quad for $80? I looked on Doug's Tubes site and it looked like the 6550s were all big bucks. Most of the KT88s were less ... DD, stick with what you know. Those Tung Sol 6550s have been working for you for awhile now. It sucks that you don't think you'll be able to get this fixed before your show. I think I'd pony up and do the credit card thing ... or plan to use the Rivera. The Sino's are Chinese (Valve Art) and Scott's tube of choice. I bought them based on his recommendation and rave reviews from LTK. The quad for $88.00 (actually $75) were EL34B's. I know KT88's are more expensive, but I didn't know they were nearly twice the money. I looked on the Splawn site and Scott lists Sino KT88's at $150.00 a quad. He still lists Tung Sol, but I only saw EL34's... no KT88's. |
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Post by sasquatch on Mar 15, 2010 17:14:56 GMT -5
Piece of cake DD... you can do it. I had never biased an amp that didn't have an externally adjustable bias pot and probe points before tackling my QR. It took me about 2-1/2 hours and I actually had fun doing it!
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Post by DonaldDemon on Mar 15, 2010 17:48:02 GMT -5
Piece of cake DD... you can do it. I had never biased an amp that didn't have an externally adjustable bias pot and probe points before tackling my QR. It took me about 2-1/2 hours and I actually had fun doing it! Cool! Hopefully I won't get killed doing it. LOL |
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