Deang Posted October 19, 2003 Share Posted October 19, 2003 Well, after almost two years of moving amps in and out of this place -- it was bound to happen sooner or later: I took a "hit". Moving the Canary into the rack was much like moving the Bruce Moore Dual 70. Heavy, well built, and exudes quality while handling. The binding posts are the first I ever used where there was absolutey NO movement while tightening. I was pretty much set to go in a few minutes. It sure is beautiful. It's especially beautiful when it catches on fire! I've never seen anything like it before. After it was shut down for a few minutes I slid it out and took the bottom off. Basically, one of the 10 ohm 5 watt resistors sitting towards the back of the board under the tubes on the right channel flared up. There was so much heat the solder melted and the resistor fell out of the board. I found it rolling around the bottom of the chassis. I did everything "right". I examined each tube before I put it in, and matched the tube in the labeled box to the labeled socket (tubes were matched, and the seller biased the amp before he shipped it out). Since the tubes only go in the sockets one way, that was pretty much a no brainer. I had the amp plugged into a Monster HTS1000, so it was surge and spike protected. I could easily replace it, however -- since I don't know the circuit, I can't be sure if something else downstream caused the resistor to go out. Bad tube, bad cap, could be several things I guess. It seemed to power up O.K., though there was a little hum which subsided after about 15 seconds -- and then whoosh. I could see the flames and smoke shooting up through the tube socket from underneath the tube. Pretty cool. My preamp was on -- but none of this excitement found it's way through the speakers. So, no Canary review until the amp goes back to the seller, to Canary, back to the seller, and then back to me (still two years worth of warranty). While I'm waiting -- I'm going to find me a nice Ultra-linear amp with beam tubes, fuses, and a built in halon system. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted October 19, 2003 Share Posted October 19, 2003 Just don't be in the room when the Halon fires up. That's beat, that's really beat. Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 Yeah, I forgot. I won't be able to breathe. :~O I'm wondering if the tube was damaged during shipment, and since the amp doesn't have fuses -- if the resistor was actually just acting as a fuse in that spot. What's the worst that can happen if I just solder in another resistor and replace the tube -- another burnt resistor and tube? Gee, too bad there isn't any such thing as a "cheap" 300B. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 19, 2003 Share Posted October 19, 2003 Dean, Is there a identical 10 Ohm resistor for each output tube ? Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 yep you can call me again -- i just didn't get to the phone in time Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 19, 2003 Share Posted October 19, 2003 Mark, You hit the nail right on the head. Just got off the phome with old Dean and it is indeed a bias resistor. It was a Vishay 10 Ohm 5W the same as I/We use. It takes a bit of current to burn out a 5 Watter ! The tube must of been dead shorted or something. Craig Quote Link to comment Share on other sites More sharing options...
leok Posted October 19, 2003 Share Posted October 19, 2003 Sorry about the bad luck. It seems you're taking it well .. do you have a backup for listening to tunes while you wait for the repair? leok Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 Hmmm. Well, I've been doing the Sennheiser HD600 thing since last week -- not exactly painful. I'm not sure what to do here, it's certainly easy enough to get another resistor in there. I'm sure it was a shorted tube. The 300Bs weren't really packed all that well. They were in their original boxes with the foam caps, and then slid into another box no bigger than it took to get the four boxes into. I'm sure they took a beating getting here. I usually give my new signal tubes a little shake, as I've received several in the past where the halo off the getter comes off. I don't shake tubes with large envelopes, and usually just turn them upside down to see if anything falls to the top. I didn't do that this time, but should of. To take advantage of the warranty, it has to go to Rhode Island, to California, to Rhode Island, and then here to Ohio. If I knew they would replace the PCB it might be worth the 7000 miles in shipping, but if they are just going to solder a resistor in -- well heck, I can do that. The PCB looks pretty bad to me -- what do you guys think? Is this a big deal? This is what it looks like now -- after I cleaned it up with denatured alcahol. There was carbon everywhere. I can see from the pics I missed a few spots (best I could do with one hand while jabbering with Craig). The remaining "black" will not come off. Pretty ain't it? Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 Where do you see "FR-4", or can you just tell by looking at the board that it's flame retardant? I take it the scorching is there for posterity -- no need to worry about removing the carbon and recoating with something? Quote Link to comment Share on other sites More sharing options...
Tubinhard Posted October 19, 2003 Share Posted October 19, 2003 LOL -- looks like I'm destined to keep this one. Oops, old cookie brought up my alias. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 19, 2003 Share Posted October 19, 2003 Dean, I think your only real long term draw back to all this is the resale abuse/Value that Mark mentioned. I'd try to score a replacement board like we talked about and just fix this one keep the spare incase you ever sell it ! Craig Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 That does make some sense, it's like we talked about this morning -- it's not likely that this will be the last time it ever happens. I think it's really time for me to invest in more tools. I think a tube tester is a must, and a variac would be nice. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 19, 2003 Share Posted October 19, 2003 A Brand new variac can be had for $100 and a descent tube tester about the same. I'd try to score a BK 707 and then have my local tube tester tech do a rebuild/Calibration for another $100. Hickoks are indeed the best but you pay a premium at $500 minimum and for the hobbiest its just not needed. Craig Quote Link to comment Share on other sites More sharing options...
bkrop Posted October 19, 2003 Share Posted October 19, 2003 Dean if you go in there and solder a new "thingy" in and something else(more costly) blows, wouldn't that void your warranty? Quote Link to comment Share on other sites More sharing options...
bkrop Posted October 19, 2003 Share Posted October 19, 2003 And the Lord, verily, smote the amplifier that dared approach the perfection that truly is His only! Quote Link to comment Share on other sites More sharing options...
Deang Posted October 19, 2003 Author Share Posted October 19, 2003 You may be closer to the truth than you realize. No amp I've owned so far has given me trouble like this -- certainly nothing making me feel I had to unload it. Yet in spite of what this thing has done, I don't have this feeling like "I just gotta get rid of this thing". I was actually chuckling last night as I was taking the bottom plate off -- like I do when dealing with my 3 year old daughter while talking her down from one of her fits. Oh wayward one that you are, yet I will tame thee. The seller is sending me two new matched JJ Tesla 300Bs for $75, and Craig is sending me a handful of the Dale/Vishay resistors (I only need one, but Craig knows me well:) Screw this, it's cleaned and ready for soldering. The worst that happens is I lose a "fuse" again. Uh...right Quote Link to comment Share on other sites More sharing options...
AnalOg Posted October 19, 2003 Share Posted October 19, 2003 Damn , Now I'm paranoid. Sometimes i leave my equipment on, so i don't have to wait for the warm up. Guess I won't be doing that anymore. Tom Quote Link to comment Share on other sites More sharing options...
mace Posted October 20, 2003 Share Posted October 20, 2003 Dean, Glad that you and your family are OK. Things going up in flames are not good! Last night I went out to hear some a local guitarist and realized when I got home that my Scott was still on. At least the tubes were just glowing and not going up in flames! I've got to be more careful. Once, my NAD started smoking and the transformer burnt up...luckily I was in the room and saw the smoke. For you NAD owners, no worries, my unit was purchased in Singapore and had the power supply modified to work in the US (120 V). Later, Mace Quote Link to comment Share on other sites More sharing options...
maxg Posted October 20, 2003 Share Posted October 20, 2003 Hang on a minute here. I always leave my tubes on 24/7. Is this a fire risk? Should I be powering them down when not at home? Holy cow I have been doing this for the last 2 years at least. Quote Link to comment Share on other sites More sharing options...
maxg Posted October 20, 2003 Share Posted October 20, 2003 Hang on a minute here. I always leave my tubes on 24/7. Is this a fire risk? Should I be powering them down when not at home? Holy cow I have been doing this for the last 2 years at least. Quote Link to comment Share on other sites More sharing options...
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