Burning smell, tubes glowing like SATAN'S EYEBALLS!

[75lespaul]

I was going to buy an amp tonight. The fellow brought it to me because he has a small apt, and I wanted to try out all the settings. This is a 91 Carvin X100B with the stock cab. The rat fur model. At first, the head was set to 16 ohms, and for some reason I couldn't locate on the cab what the ohms were. I asked him if it was 16 and he said yes. We plugged in the amp, and it had a loud hum. It sounded thin as well. Then I smelled something burning, and noticed that the two power tubes that were being used were really glowing brightly. JJ power tubes by the way. We turned it off and they were too hot to touch. This was after only about three minutes. That's when I flipped on another light and saw that the cab was 8 ohms, though that alone shouldn't have caused any problems. He had slo-blo fuses he was giving me, but the amp did not call for slo-blo. He said with a regular fuse, it blew.:argh: We let it cool down, put the ohms to 8, but when turned on again, it started humming and I turned it off before any burning smell could come about again because the tubes were hot and glowing after only a few moments--not even a minute.

Does this sound like it just needs tubes, or is there a deep, dark secret going on here. Thanks bros!

 

[BloodRose]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

Im not well versed in tube amp tech, so Ill watch and learn here, but I did wanna post cuz I want to hear what you think of it when you get it going.. I hear such mixed reviews of these. Some guys love em, some loathe em. The haters really hate, but they musta been popular enuff that they brought em back and cancelled the mts.

Id guess maybe to hot a bias.?? Or maybe you just got one thats gonna let you blaze on the board.. haha.. couldnt resist a pun..

 

[Chickenwings]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

screen resistors ill wager

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

screen resistors ill wager

That's what I was thinking, but I'm just a guesser when it comes to electronics.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

Im not well versed in tube amp tech, so Ill watch and learn here, but I did wanna post cuz I want to hear what you think of it when you get it going.. I hear such mixed reviews of these. Some guys love em, some loathe em. The haters really hate, but they musta been popular enuff that they brought em back and cancelled the mts.

Id guess maybe to hot a bias.?? Or maybe you just got one thats gonna let you blaze on the board.. haha.. couldnt resist a pun..

I wanted this amp for a couple of different reasons. First, I hear the clean channel is great, and I wanted a backup for my main rig. Next, the ratfur EL-34 models are supposedly better sounding as far as the distortion. The final reason, is there are a few mods you can supposedly do to these that make them sound really hot, and they are very reasonably priced because nobody likes them. Here's a few links to show a guy who did these mods, what he did, and a vid he posted afterwards.


http://www.thestompbox.net/forum/showthread.php?12608-i-like-this-amp-Carvin-X100B-MK-IV/page3
Mods posted in #28

vid he did after the mods. This link is in the above thread as well.
http://www.youtube.com/watch?v=LL76f2nasdI&feature=youtu.be

 

[Gearjoneser]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

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:lmao:

 

[trevorus]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That amp needs serviced. It could have had tubes changed without biasing, or even worse things. I'd buy it if I really wanted it, because I know how to work on them. Just be sure you want to buy a repair bill.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That amp needs serviced. It could have had tubes changed without biasing, or even worse things. I'd buy it if I really wanted it, because I know how to work on them. Just be sure you want to buy a repair bill.

Yeah, I don't. Too many of these at good prices around. This model amp just looks like a good option for the clean channel plus the 25/50/100 switch as my rig is a Vox Tonelab LE through a Univox set very clean and a 60 watt cabinet. The Univoxes have shot up in price and the Carvins haven't, so...

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:lmao:

After last night, I can't argue. However, as a TOASTER oven, I may have to disagree with you.:alcoholic

 

[ErikH]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That happened to my Marshall several years back and the power transformer blew. The tubes glowed like that, the chassis got real hot and then it shut off. Besides the PT, some resistors went and bias components.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That happened to my Marshall several years back and the power transformer blew. The tubes glowed like that, the chassis got real hot and then it shut off. Besides the PT, some resistors went and bias components.

When I shut it down, I felt all around, and the trannies and chassis were cool. Only the tubes were hot. Maybe that's a good sign, lol.

 

[ErikH]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

When I shut it down, I felt all around, and the trannies and chassis were cool. Only the tubes were hot. Maybe that's a good sign, lol.

That could be a good sign. I could've fried an egg on my chassis before it went.

Thankfully I was able to get it fixed. It sounds better now than it did before. Retubed, biased, new filter caps.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That could be a good sign. I could've fried an egg on my chassis before it went.

Thankfully I was able to get it fixed. It sounds better now than it did before. Retubed, biased, new filter caps.

He's asking $300 now for the amp and matching 4x12 before he puts any work into it. I may have to think about that because I was going to give him $550 last night. Don't know that it will need $250 in tech work, but who knows? Wish I could bring it to a tech first, but he doesn't want to go through all that hassle. Those cabs sell really cheap so $300 won't be a good deal if a tranny is fried. I don't need the cabinet, but I thought $550 for the head, cabinet, and footswitch was just about fair so I was gonna get the whole shebang.

 

[trevorus]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

That doesn't sound too bad, honestly. Like I said, though, I do my own work.

 

[Ascension]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

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:lmao:

BS!! I ran Carvins on the road for years and they never failed. The old MTS Valvmasters and X100's are built like a flipping tank.
On resale value tried to buy a used Carvin lately? Resale has gone through the roof and you loose more on a new USA Fender or Gibson today that you do building a Carvin!

 

[Ascension]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

He's asking $300 now for the amp and matching 4x12 before he puts any work into it. I may have to think about that because I was going to give him $550 last night. Don't know that it will need $250 in tech work, but who knows? Wish I could bring it to a tech first, but he doesn't want to go through all that hassle. Those cabs sell really cheap so $300 won't be a good deal if a tranny is fried. I don't need the cabinet, but I thought $550 for the head, cabinet, and footswitch was just about fair so I was gonna get the whole shebang.

$300 will depend on what's in that cab. Could be the Eminence built Carvins if so they are pretty worthless but also could have come with Celestians ether 75 or vin 30's. Also depends on the head is it a Hot Rod mod head or does the pull pot say High lead? Those early Hot Rod Mod amps were monsters!
A solid head can be bought for 350 to 400 in working shape look for a hot rod Mod head that came with EL34's.
Here is a clip with me playing a 88 V220 through the old 1988 rat fur X100B I had with the hot rod mod running through a 4/12 loaded with 75's at my old church. This was recorded with set of mics and a mini disk at the sound desk in the 10,000 seat santuary.
http://soundclick.com/share.cfm?id=4453782

 

[Ascension]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

He's asking $300 now for the amp and matching 4x12 before he puts any work into it. I may have to think about that because I was going to give him $550 last night. Don't know that it will need $250 in tech work, but who knows? Wish I could bring it to a tech first, but he doesn't want to go through all that hassle. Those cabs sell really cheap so $300 won't be a good deal if a tranny is fried. I don't need the cabinet, but I thought $550 for the head, cabinet, and footswitch was just about fair so I was gonna get the whole shebang.

You do know that you can buy a new X100 with the factory warranty for just $600 do you not?
http://www.ebay.com/itm/Carvin-X100...376?pt=LH_DefaultDomain_0&hash=item2a32dfae48
On the old ones make sure you get a working footswitch or plan on spending $75 or so to get one also.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

You do know that you can buy a new X100 with the factory warranty for just $600 do you not?
http://www.ebay.com/itm/Carvin-X100...376?pt=LH_DefaultDomain_0&hash=item2a32dfae48
On the old ones make sure you get a working footswitch or plan on spending $75 or so to get one also.

Actually, they're having a nice sale where you get the head, footswitch, and your choice of color for 599 on the website. Nope, not the hot rod head. The cab is the regular BR12s which seemed to have a good era, then a bad era, now they're good again. This one is supposedly a 91 and I don't know if they were the good ones or not, but I was going to eventually reload the cab anyway if I didn't like the speakers. All moot because I told him I wasn't interested anymore. Got a line on an 88 for $250 with no footswitch, but its the 6l6 model. I only want for the clean channel, so that will work. I really wanted this one though!

 

[glassman]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

The Carvin X100s from that era are actually pretty well built. Earlier ones had a nasty habit of burning a hole in the circuit board...like a 2 inch hole!

Here's what I think went wrong with that amp: A power tube shorted grid to grid which caused it and the other one on that side to supernova. It probably did some damage to the bias circuit in the process but nothing serious. The first clue that it was only on one side of the output is that it didn't blow a fuse immediately. This would be a pretty routine repair for a decent tech.

The interesting thing about these amps is the 25/50/100 watt switch: it has nothing to do with the output portion of the amp. It actually changes the plate voltage to the phase inverter, creating more or less headroom, depending on the setting. The 25 watt setting is about 90 volts while the 100 watt setting is close to 300 volts. Pretty slick.

You might want to reconsider if you have a good tech in your area...this isn't a big buck repair.

 

[BloodRose]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

I wanted this amp for a couple of different reasons. First, I hear the clean channel is great, and I wanted a backup for my main rig. Next, the ratfur EL-34 models are supposedly better sounding as far as the distortion. The final reason, is there are a few mods you can supposedly do to these that make them sound really hot, and they are very reasonably priced because nobody likes them. Here's a few links to show a guy who did these mods, what he did, and a vid he posted afterwards.

http://www.thestompbox.net/forum/showthread.php?12608-i-like-this-amp-Carvin-X100B-MK-IV/page3
Mods posted in #28

vid he did after the mods. This link is in the above thread as well.
http://www.youtube.com/watch?v=LL76f2nasdI&feature=youtu.be

Good info! Thanks! Yeah, the orig ones were supposed to have a killer clean and be pretty mod
friendly.

 

[75lespaul]

Re: Burning smell, tubes glowing like SATAN'S EYEBALLS!

Ooooooh, I don't know what to do now, lol. If all goes well, I'm picking one up with the 6L6 tubes this weekend with no footswitch for $150. Can't beat that with a stick, and it was serviced within the past two or three years. I really want this carpeted one though, lol. So you guys think its a decent deal for three bills? I was thinking I'd pull the trigger at $250.