Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Viktor on May 01, 2011, 07:51:18 AM
-
Hi! I just got my bottlehead crack kit this friday and yesterday evening I started to put the things in place, then I noticed that one of the rca-jacks looks really strange, I tried taking a rca-cable to test if it fit and it sure did, do you think it is something I should worry about?
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fassets.head-fi.org%2Fd%2Fdb%2Fdbf6564b_bild-2.JPG&hash=a24f736304e2356a7dfd447d858bf710a9abe903)
Oh! And also one more thing. I get confused with the safety ground, I currently have two screws left, one philips 3/8" and one normal (star) 3/8" and one #8 lockwasher and one small lockwasher. In the manual it says that I should use #8 screw, lockwasher, soldertab, lockwasher but I only have ony big lockwasher left and one small, and the small one doesn't fit the screw.
And what should I do with the screw thats left? I've read trough the manual several times but I can't figure out where to put the last one.
Also one last thing. I tried to begin with the soldering today and accidenly, I am a beginner, burnt the corner of the power-cord connector. It's only in the corner of the connector so I don't think it should be a problem?
I'm having some problem with cold-joints as well, I think it is kind of hard to tell when the joint is good or not, to me all they joints so far look kind of dull and boring. Maybe it is the solder, I'm using 60/38/2 copper.
Thanks
-
For the RCA jack as long as the outside part does not touch the center pin of you interconnect, it should be OK. You can test it with your meter.
I don't have this kit so I can't help with the screws.
Ditch the solder. Go to Radio Shack, Fry's or whatever and get some plain rosin core electronic solder. I have tried that Cu stuff and hate it. One less thing...John
-
There has been some variation on the look of RCA jacks, but they work fine. We may have miscounted the washers in your kit. The safety ground solder tab has its own teeth so leaving one #8 lock washer out should not be a problem. I'm not near one of our manuals at the moment. Is the extra screw perhaps the self tapping one that it used to thread the terminal strips?
-
Ahh okay, that could be it. I figured that it wasn't so important.
Regarding the soldering I tried to take a picture with my phone but it was hard to capture the solder points in a good way. I also checked the cables with the continuity function on the DMM and it said that the resistance was 0.01 so maybe it will work? After these failed points I'll def. get some normal 60/40 solder!
-
Checking the continuity is the right approach if you are concerned about how good the solder joints are. I would not worry about resoldering the ones you have already soldered if they are testing OK.
-
Okay! I went and bought some 'normal' 60/40 solder and it is much better. I think I have completed more than half of the build now, its going okay! :)
Really fun too, and I am learning something I couldn't do before so that's really nice!
-
Hi Viktor,
That's the spirit! And when it's done and making sweet music and you can look at it and tell yourself that you built it, well, then you'll understand why so many of us are so addicted to Bottlehead!
I wish I could convince a few more of my audio buddis to give this a try -- both for the experience of building your own gear, but also for the immense pride of ownership, and of course the superb sonics.
-- Jim
That's the
-
Okay! I went and bought some 'normal' 60/40 solder and it is much better. I think I have completed more than half of the build now, its going okay! :)
Really fun too, and I am learning something I couldn't do before so that's really nice!
I would just rewet the solder joints that you made with the other solder. Don't glob a bunch of solder on them. Rather put a little solder on the tip of your soldering iron and touch it to the previous, dull, solder joints. Then give it a little solder on the other side of the joint to wet the joint.
-
Ok! I'm done all the voltages checked out fine and everything. just the last part left,
'Final check
-
The tip is the contact where the tip of the headphone plug makes contact - the farthest contact from the chassis on the jack. The ring is where the ring in the middle of the headphone plug makes contact - middle contact on the jack. I will leave determining the sleeve connection as an exercise for the student.
BTW a google search for TRS connector will turn up several hundred images.
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fhome.comcast.net%2F%7Ephugger%2Ftrs.jpg&hash=fabcb571ef48557b1dfca097f785afe21b8bd69a)
-
Thanks for a superfast relpy! Yeah I googled that but I couldn't find anything on the connector itself, I mean on the amp. Anyways, from what I understood now I should just check the voltage on the ring terminal where the white wire goes?
I did that and the voltage didn't reach 9V, maybe seven or something like that and then it dropped back to zero, is that okay?
-
Viktor,
That's it! You should be good to go!
-- Jim
-
I fired it up but I get some slight cracking (hahaha) noises from the left channel, could this be due to a bad joint somewhere?
edit: Okay I tested to run it without any source and theres still a crackling noise in the left channel. Would a good guess be that theres something wrong with the solderings on the headphone jack?
-
Not necessarily -- could be any number of solder joints in the left signal path. Try checkin the tube sockets first -- both the wires soldered to them, and try resetting the tubes a couple of times to clean the contacts a bit.
Most of the time I've exerpeinced crackling it has been a bad tube socket connection. Since all your resistance and voltage checks were ok, I'd just try the tubes first.
-- Jim
-
Viktor,
That is why I suggested going over all your previous solder joints after buying better solder.
Now you are ready for a new/old trick; new to you old to the board. It is the chop stick test. You listen through your headsets while prodding each solder joint with a chop stick. You can use anything that is insulated but I guess the first thing used was a chop stick.
When you find the one that crackles you clean it and resolder it.
-
Thank you! Will definitely do that today. I listened for a very short time and the sound was wonderfull by the way but I didn't wan't to destroy anything so I shut it off.
And I guess the manual is correct
'Remember, we don't learn from doing something right, we learn from our mistakes.'
I'm learning loads from doing this! Is there any good read on the web for how the circuitry itself works? I'm a physics student so I am always interesting of finding out how things work!
Thanks a million
-
Congratulations on the build and being down to simple troubleshooting (my first DIY build had me chasing a bad power supply rectifier...you did much better than I did!). I bet you will enjoy this amp more than you have any other amp: you KNOW how it works from power supply to signal input to signal output. What a great feeling...enjoy!
John
-
I did as jrebman suggested and just wiggled the tubes back and forth abit, took them out and put them back in and now the sound is gone. I really have a working crack! Sounds wonderfull but as I remember from my Fender guitar amp tubes do need some burn in to sound their best?
Also, thanks for all the helpfull advice, quick replies, and nice atmosphere! Wonderfull resource for help and information :)
-
Sounds wonderfull but as I remember from my Fender guitar amp tubes do need some burn in to sound their best?
/quote]
Yeah, Viktor - they sure do need some burn-in time, as do the capacitors in any circuit. Now you can spend your lunch money on new-old stock tubes to find the "right" combination for your musical tastes...
I settled on a NOS Amperex 12AU7 for the gain stage, and a vintage Sylvania 6AS7G to replace the stock 6080 in the current stage... the positives are a.) the 6AS7G looks like a real "bottle" <g> and b.) the Amperex sounds really sweet to me over my Senn HD-600s.
Congrats on your first Bottlehead kit! As a physics student, you'll probably be able to visualize the space charge in those nicely glowing tubes...
Enjoy!
-don
-
Hi again! It is a bit weird with the cracking noise because I thought it was gone but now its back again. At least for a very short while when the amp is heating up, then it's gone....
I tried to poke around inside it but that didn't do anything.
-
Viktor,
Sounds again like a flakey tube socket connection and/or ttube, and that it's making a better connection as things heat up and expand abit..
Sounds like the rest of the amp is doing what it should though, so the tubes and sockets are where I'd be looking for an answer.
-- Jim
-
Okay I've had a alot of other things to do so I haven't had time to look into the issue and actually it went away completely but now its back again. I've checked the solders and they looked fine and I also resoldered some of the connections but it doesn't seem to help. I also tried the chop-stick test but the cracking/popping noises are very irregular so it's hard to know if there's anything happening when I poke around... :(
I tried to 'clean' some of the pins on the large tube to get a better connection but that didn't help either...
edit:
Okay I found out that when I wiggle the big tube I can make the cracking noise appear/disappear but when I poke the connections there's I can't produce the noise...
-
Try inserting and removing the big tube 5 or 6 times. This will clean the tube pins and the tube socket.
-
Just thought I'd throw this out there as well - do you happen to have a cordless phone, cell phone, router, etc. sitting near your amp? While I haven't had this issue with the amperex 12au7 in my crack, I have a pair of fairly pricey amperex e88cc PQ's (another 9pin variant that I used in my prior Woo headphone amp) that pop/crackle off and on if they are within several feet of any sort of radio. Took me a week or so to puzzle out the cause of those crackles, and I just wanted to make sure your issue doesn't boil down to something so simple.