Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: bmurph7 on October 13, 2012, 01:36:17 PM
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I am attempting my first project, and I need some help with a few issues and a question answered. First the question. I am fairly new to soldering, and am using a 40 watt Weller iron. I have read about, and seen on Tyell's video, what is called "wettin", but when I try it with my iron, the solder just rolls off. Is there something to do to prep a new iron?
Now to the problems with my Crack attempt. When I finished, the amp didn't pass the first ohm test. So I started looking, and found some poor soldering which I repaired. The amp then passed all the ohms tests, but when I powered up, the first volt test was way out (220). Further checking revealed I had incorrectly oriented the 8pin tubed holder. I removed it and resoldered but now the ohms on terminal 13 read a steady 532 with no increase from there. According to the manual, the oms should rise steadily to 270K. This was the case before I realigned the tube mount. I also seem to have some solder in one of the pin holders and the tube does not fully seat. Can the solder be removed, or do I have to replace the mount?
I would greatly appreciate any help as my knowledge is very limited. Thank You
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sorry i can not help you with your crack issue. (i do not have one myself). but i have a few tips for your soldering technique. if you can not wet the iron tip with the solder, i wonder how you managed to make good solder joints on the crack. if the solder does not stick to the iron it is a sign for an oxidized and/or dirty tip. best is to clean it with a wet sponge or some steel wool. get your iron nice and hot and dip it in a wet sponge, those typically come with the soldering station. right after that feed some solder to the iron. it should melt right on it. then repeat that process a few times, wipe off on the sponge and wet with solder again etc. you should now have a nice clean iron tip that is ready to use. i find it best to do this little procedure once pretty much before each joint unless you solder a few joints in a row. but basically the hotter your iron the faster it will oxidize again. so you need to keep the tip clean and shiny to make a good joint an oxidized tip will not transfer heat well and you are more likely to get cold joints. there is tons of good tutorials on youtube.
if this is not working with your iron it is either not hot enough or you solder might be the wrong kind.
go over the crack again, double checking all the parts and their orientation. might be best to reflow all the joints if your tip was not properly primed all this time. do not rush yourself and be patient. working step by step will eventually bring you to your goal. good luck.
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Tube socket ... If solder flowed all the way down the solder tab and loaded up one of the sockets tube pin contacts, you may have to resign yourself to the fact that it may need to be replaced. But, maybe not. If you remove all connections from the affected solder tab, you may be able to get the solder to flow back down and out of the contact. You would have to heat the contact while orienting it so that it is facing down (top of the socket facing up). Maybe the solder will flow out of the contact and back down the solder terminal. Unfortunately, there is no way to get a solder sucker or solder braid down into the contact. However, another possibility may be to have a helper poke something down into that contact from the top while you apply heat to the solder tab from the bottom. Maybe a staightened out paper clip might work. The helper would have to get it down in there while you applied enough heat to flow the solder that is in there. Just some things to try since you have nothing to lose. Just make sure you dont slip and hit adjacent wires or components with the hot iron. And, if you do have a helper, he should probably wear gloves, that paperclip will probably get pretty dang hot.
These arent "approved" techniques, obviously. Just things of the top of my head. And believe me, I would probably try them myself after I cursed for a while for getting the solder in there in the first place ;D
One point though ... as mentioned by sl-15, I would have to wonder about your soldering technique. You shouldnt have needed that much solder and/or heat for that long to allow the solder to flow as far as it did down into the contact. Just out of curiosity, can you post the solder type that you are using. It doesnt happen to be lead free does it?
Dont worry, you'll get there. Folks here will help. The forum will allow no man or woman to go without their Crack fix ;)
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Solder sucker might be the trick. :D
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Thanks to everyone for your help. To answer Laudanum, the first time I built the amp, I used a solder from the local Sears store. It is called Fine electrical rosin core solder, and is 60% tin and 40% lead. When I reorientede the 8 pin socket and resoldered some other joints I used a silver solder that is 3% silver, other components unknown. What is a good solder for my project?
Also, is a basic 40 watt Weller iron good, or should I be using something different? If so, what is recommended?
Maybe my issues with the bad ohm readings at terminal 13 has to do with bad soldering. There is a lot going on at that terminal, and it is hard to get to.
Again, thanks for all the help from everyone.
Brent
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Silver bearing solder, 1%, 2%, 4%, need more heat than 60/40 solder. That heat can either damage a component or not get to the joint and cause a bad solder joint. Until you get a couple of kits under your belt save the silver solder.
A 40W iron should do fine for the standard solders and the Bottlehead kits.
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Graingers right as usual. Some of the 2% silver solders are pretty easy to work with as long as they are lead based. But the 60/40 is a good choice and probably your best bet for first time soldering.
If your Weller is a soldering station with adjustable termperature, it's better/easier. But a 40 watt pencil iron will work fine. The non-adjustable irons are at full heat so you may just need to be a bit more deliberate and quicker. The adjustable heat stations let you set the temperature to the job, so obviously a bit more precise for a particular job. No worries though, you'll get the hang of soldering in no time.
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Thanks everyone for the help. I have ordered a new soldering station and 60/40 solder. Also a new 8 pin socket. I have to do everything by mail, so I will post again after I have attempted the repairs
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Post back and let everyone know how it's going. Of course, ask for any help or tips that you may need. Im not a guru like a lot of these guys but Im pretty decent with an iron and glad to help where I can.
Do keep in mind that you do still will need to be fairly deliberate and efficient with an adjustable termperature station. But it's superior because you can dial in the temperature so you have enough heat to get a good joint without as much worry about melting everything within the blink of an eye. You will have to experiment some with the temperature setting but it isnt rocket science. You'll be glad you made the purchase, well worth it.
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if you are patient enough check out this video
http://www.youtube.com/watch?v=vIT4ra6Mo0s
it might have some obsolete info in there because it is so old but gives you a good understanding about what is important when soldering. my first soldering attempts were with a 25 watts weller pencil and i could not get it to work properly. no good tutorials on the internet back then and i thought i am just not doing it right. years later i finally pulled the trigger on a bottlehead kit. i bought a 40 watt soldering station and after some practice my soldering skills became quite good. you are on the right path. good luck
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I bet that you will be as impressed with a soldering station as I was when I purchased one. I did learn a long time ago, that a good mechanical connection with the wire and the post are helpful to ensure a great connection every time. You may also notice differences in solder from different manufacturers. I have chosen 'Wonder Solder' a long time ago, and probably will never change. One last thing; there is a tip cleaner that some people use that just amount to a copper type of 'wool'. I have heard many good things about them. When you get the hang of all of this it gets to be a great time.
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A Copper Chore boy will work as a tip cleaner. Just a couple quick swipes. But mostly I use a damp sponge and an occasional back and forth swipe on a Kester tinning block.
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Thanks for all the help everyone. I watched a video on Utube about tinning an iron, so I tried it on my old one, and what a difference! I also have some old pieces to practice on when my new station arrives so I will make sure I am comfortable with it before I start redoing my Crack. Thanks again. It's great to have such support!
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It seems to apply to everything pertaining to soldering. I mean, just last night I used some solder wick that cheap. It was a realllll pain in the ass! Worked poorly, smelled bad, and no, it wasn't a braid of my wife's hair.
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I have a new tube socket coming from the Queen, and while I wait, now that I have my old iron properly tinned I thought I would disassemble my amp. I found the packaging on the silver solder I used, and it is lead free so I am removing it and will resolder with new Kester 60/40 which I understand is pretty good stuff. My question is can I replace some of the wire with Radio Shack wire, which is copper, and am I damaging any resistors etc. and if so, how can I spot the damaged ones?
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My question is can I replace some of the wire with Radio Shack wire, which is copper....
Why? If the stock wire is the same as mine, it is good quality Carol, (General Cable) tinned copper with PVC jacket. Radio Shack wire would, IMO, be of dubious quality. I did use mil spec silver plated OFC with Teflon dielectric for my signal path. It was a bit brighter, sounding slightly more detailed. To me, an improvement, but hardly dramatic.
Cheers,
Geary
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You can verify the resistors by putting a meter on them. Don't do it after they were just removed. The heat can alter the reading. But after 10 minutes, or 5, they will read true.
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Lead free ... ouch. That explains it. That said, if you were able to get some good solder joints with it, you may want to leave them alone. If they are all suspect, then that's another thing. Lead free is a royal pain and I wouldnt use it for anything, plumbing excepted, but if a good joint is made with it, it works fine. It isnt exactly a piece of cake to desolder either, especially getting it to flow so you can wick up with a solder wick. Needs more / longer heat and you risk overheating components again. That's the only reason why I would consider leaving those solder joints that may be ok. Anyway, I use the Kester 63/37 Eutectic (Kester 44) for most things electronic. But the Kester 60/40 is good stuff. You'll immediately notice the difference and rap yourself on the head for using the lead free. Not your fault, you didnt know. Now you know where to ask ;)
Im also going to assume that the OP is asking about wire because of insulation pull back with all that heat from using the lead free. Eileen surely would have supplied some more wire.
I've tried the lead free just to check it out back when they had the lead free frenzy, but I never soldered a project with it, thankfully. So this is something I am not sure of so I'll put it out there for others who may know ...
If you have a suspect lead free solder joint, can you re-flow, adding a bit of leaded solder and to get a solid joint? In other words, will the leaded flow with the lead free and is there any problems with the mix?
I ask because this may help the OP in not having to desolder everything. It would be easier to reflow with a little lead free if it's ok to do so. Assuming of course that there isnt already a boat load of lead free on the joint.
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bmurph7 ... if you are in the USA and dont mind waiting a few days on the postal service, I would be happy to send you enough of the insulated wire to be able to rewire your amp. Same type (insulated solid core) and gauge (20, I believe) as Bottlehead includes with the kit. I dont believe that I have any of the buss wire but that should be re-usable without any problem. If you'd like it, send me a PM with your address information and I'll get it out in a mailer today or tomorrow. Gratis of course.
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Laudanem.. Thanks for the offer. I still have some wire left from the original build, and I haven't received the new parts from Bottlehead yet so maybe they will send some wire. So I think I should be OK. I did get my new soldering station today, but won't have time to play with it until next week.
Thanks again for the offer.
Brent
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No problem. The offer is open if you need the wire.
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" The offer is open if you need the wire.
That's what I love about this place...John
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After a long delay due to work, I finally got the parts I needed and reassembled my Crack. Testing was good in Ohms tests, and good for voltage until clumsy me shorted an LED. I replaced it, but I dropped the 6080 tube from chair height onto carpet. Now on terminals where I should get 170v, I get 202v, at terminal 7 I get 0v instead of 100v, and at B3 I get 0v instead of 100. All the voltages that should read 170v are at 202v, #9 is 125v s/b 100v, #15 is 217v s/b 185, #21 is 230v s/b 206. Did I break the tube? Or could something else be wrong. I didn't get a chance to check the B voltages before I shorted the LED and subsequently dropped the tube, but #2, #4, #7, #9, #13, #15, and #21 all had correct readings.
As always, I would appreciate any help I could get.
Thanks
Brent
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Hello Brent,
If terminals 1-5 read the correct voltages, then you can be certain that the 12AU7 is functioning correctly.
7 and B3 are tied together, and 0V there indicates that this half of the 6080 isn't drawing current (9/B7 is the other half, which is operating appropriately).
What I would check is to ensure that there is voltage on B1, it should be the same as terminal 2, and voltage on B2 (which is nearly mandatory). Next, measure the resistance from ground to B3 to be sure the cathode resistor is in properly, being aware that you might have to pop the 100uF coupling cap out. Since you haven't mentioned so, I'm assuming you don't have the Speedball.
If all these checks pass, then the 6080 may have been damaged, but this is a super tough tube, so it seems unlikely.
-PB
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PB
Thanks for your help. B1 voltage is 90v, which the manual call for. B2 is 203v. The manual calls for 170. The resistence at B3 is 2.9k ohms, which the manual also calls for. I did not remove the cap. Since it checks OK according to the manual, I wasn't sure I needed to remove the cap. Is there a way to check the tube?
Thanks
Brent
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Is there a way to check the tube?
Well, you could look around for somebody with a tube tester, but you have verified the correct bias voltage, that there is plate voltage, and that the resistor is properly connected and not shorted, so in a way you have tested your 6080.
I'd snag another one and you should be back in business.
-Paul
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Sweet success! Bought a new tube and everything is good. Amp sounds great! Thanks to everyone for all the help. I learned a lot, and am looking forward to my next project.
This was my first time for something like this, and I was amazed at all the help I received. Again, I can't thank everyone enough!
Brent