Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: hoy83 on July 23, 2021, 01:52:27 AM
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Hi guys just want to share some pics to ask if im doing the assembly right?
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There are oodles of common hardware mistakes that are pretty common, but I don't see any in your photo.
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thanks, I think I will proceed to wiring and soldering now. Might run to some troubles using the multi-meter as I have never used it before in my life and I won't know where to stick the probes. I was quite surprised that I actually had to do the threading myself on the 6 terminal thing. I was so afraid I would break off the terminal when using the tapping screw when I applied too much force. And I was worried if I was putting the star and round washers with those teeth the correct way, it might have been facing the wrong way (if there was a way it was supposed to be facing with the teeth). And another thing was on the power brick (the heavy center part), it says 13 instead of 18 so I'm wondering if it's a typo from bottlehead or something.
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You can practice with your meter measuring battery voltages and measuring the resistances of the resistors in the kit.
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are there correct sides where the round and star washers should be facing? or it's all the same just slip it on the screw?
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They can face either way, but be sure they are on in the correct order.
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To what setting should i set my multi meter to when measuring what voltage i need for the transformer and resistance? Attached is an image of my meter..
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The image didn’t attach.
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Just search for "How to use a mutimeter" Many tutorials out there!
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Sorry modifying post with image.. by the way.. when i measured the power transformer for correctness in the 210 to 250 range.. the first measurements were 7.06 to 7.08.. the 2nd was 192.3 to 193,5.. am i safe to proceed? The manual says 6.5v plus ir minus 20% and 175v plus or minus 20%.
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What is your AC powerline voltage?
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You mean the wall outlet? It ranged between 223 to 224
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OK, which set of power transformer wiring instructions did you use?
6.5V + 20% is 7.8V.
175 + 20% is 210V.
I ask about which wiring configuration you used because there isn't one for 210-250. There's a configuration for ~220V, one for ~230V, and one for ~240V.
If you have 223V and you wire for the 220V configuration, I would expect your power transformer measurements to be super close to what's in the manual, as that's 1% off the target powerline voltage.
Also be aware that dying batteries in a multimeter will do really weird things.
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Oh sorry i used the 210 to 225 configuration
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That would all be OK then.
-PB
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Oh the bigger tube isnt glowing.. just one side of the smaller tube..
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Here's a picture..
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One side of the smaller tube would be the solder joints at A4/A5 not being well soldered.
The 12AU7 is downstream of the 6080, so it's unlikely to have a dark 6080 and a lit 12AU7, but it's possible if the solder joints at B7/B8 are flaky that the green wires could be connected to each other well but not the socket pins. When in doubt feel free to post more photos of the inside.
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Here are some pics.. i added a lot of solder on the green wires..
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my center socket has 2 holes so I soldered them both sticked together..
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fixed it, it was a4 and a5 not soldered well.. the smaller tube is glowing on both side now.. just that the larger tube in the center has no glow..
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how ever I put the first set of wires in b7 and b8 on the top hole, while the 2nd set of green wires (with the trimmed) in the 2nd lower hole of b7 and b8, then soldered them both up..
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You need to wrap the wires up and over the socket pin connections, then solder them. If you just take a wire and pass it through a hole, then solder that, you won't get a great connection. A9 is a perfect example where the wire pokes through and off to the side. This wire needs to be bent up and over the tube socket terminal, crimped, then soldered.
The wires going from the power transformer to B7 and B8 need to be pressed down against the chassis plate.
The solder joint at B8 is not adequately heated to be properly soldered.
It's also worth mentioning that the 6080 tube has a keyway on the base and if you don't plug it in properly, it won't light up. It may also break when you go to remove it from the socket.
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Is the 6080 the big one? How do u properly connect it?
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Yes, the 6080 is the bigger tube. It should have 6080 written on it.
Pull it out of the socket and look at the bottom. There's a black plastic post in the middle of the base with a piece that projects out, that needs to be plugged in so it fits properly into the 8 pin socket.
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is this ok?u
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oh yeah it's glowing now, it wasn't inserted the correct way the 6080! thanks..
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That's looking better. The ends of the green wires going through the sockets can be wrapped around and crimped so they stay tight.
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thank you again, I think I'll call it a day and continue tomorrow.. its 4am here.. thanks so much for the help
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Yes, bend the wire into a hook, insert and crimp it round the connector. It should be fixed mechanically before soldering. It's more than just a belt and braces approach, you get more surface area for the solder to flow around. The solder should look smooth and shiny before you quickly remove the solder tip. Don't give it a poke to try and fix if if it looks a bit dodgy, flow it out again.
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so... I THINK, I finished assembly of the crack.. problem is I don't know how to test resistance.. the instruction says to attach the black lead to the ground buss, I don't know which one is the ground buss on terminal 12u.. I attached pictures of where I clipped my black lead for the multi meter. and where should I set the multi-meter dial to? to 12 o clock on the ohm sign?
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anyway if I got it right and clipped the black lead on the correct place, I'm getting more than 0 ohms on some that needs to be 0 ohms..
here is the breakdown:
Terminal:
1. * (I don't know what this asterisk means so I didn't measure those with asterisks)...
2. *
3. 0.1 to 0.2 ohms
4. *
5. *
6. 0.1 ohms
7. 2.952 k ohms
8. 0.1 ohms
9. 2.944 k ohms
10. around 39. something with an M beside an ohm sign in the dmm
12. 0 ohm
13. *
14. 0.1 to 0.2 ohms
20. 0.0 ohms
22. 0.0 ohms
B3. 2.952 k ohms
B6. 2.954 k ohms
RCA jack center pin black. 103.1 ohms
RCA jack center pin red. 99.1 ohms
RCA jack ground tab black 1.1 ohms
RCA jack ground tab red 0.3 ohms
I think I got it wrong..
thanks in advance for any help..
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Touch the clips together, what does your meter read?
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I don't know which one is the ground buss on terminal 12u..
12U is a ground connection. I'm not quite sure what you're asking, that's where your black meter probe should connect.
1. * (I don't know what this asterisk means so I didn't measure those with asterisks)...
The asterisk is explained on page 47 where the resistance values are posted.
6. 1.0 ohms
7. 2.952 ohms
8. 1.1 ohms
9. 2.944 ohms
10. around 43. something with an M beside an ohm sign in the dmm
The values at 7 and 9 should be 2.9K, not just 2.9 (same for the center pin of each RCA jack). 43m would be OK on 10 (that would be 0.04 ohms) but 43M would definitely not be OK.
The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.
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Touch the clips together, what does your meter read?
0.0 ohms when I switch my multi-meter to the ohm sign
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0.0 ohms is very good, most meters read around .02-.03 ohms with the probes touching and you can consider that 0 ohms.
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12U is a ground connection. I'm not quite sure what you're asking, that's where your black meter probe should connect.
The asterisk is explained on page 47 where the resistance values are posted.The values at 7 and 9 should be 2.9K, not just 2.9 (same for the center pin of each RCA jack). 43m would be OK on 10 (that would be 0.04 ohms) but 43M would definitely not be OK.
The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.
yes I corrected the values on my previous post, it's k. not sure with ten, do you mean a small letter m or big letter M? I switched to manually holding the probes with my hand with the black lead on the 12u terminal and using the red lead to measure, it measure below 1ohm as opposed to using an alligator clip which I think is a bit inaccurate in giving me readings a while ago. I updated the values on my previous post.. so is it correct that I just attach my black lead to 12u that would be the correct way? I'm really suspicious about the terminal 10.
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with terminal 10 my dmm goes crazy, going from 40kohms to 80+kohms..
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with terminal 10 my dmm goes crazy, going from 40kohms to 80+kohms..
The value at 10 would have me wanting to see the headphone jack wiring and the octal socket wiring in a bit more detail.
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Thanks, that seemed to work, there was a loose connection on the headphone jack, soldered it and terminal 10 was 0 ohms..
Ran into a problem again though.. the voltage test was a little over the limit specified in the manual.
Here are the terminals:
terminal 2 188v - 189v
terminal 4 189v
terminal 7 116.8v
In the manual it says terminal 2 and 4 should be around 170v, and terminal 7 is at the maximum 115v. Is this ok?
thanks in advance.
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I wouldn't be too concerned by those.
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well I guess I made it.. thank you very much for all the help.. I'm using the amp right now with my headphones, sounds good. Thank you to sir Paul Birkeland for all the help and the others too.
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Is it normal for the chassis to be a bit hot when running the amp?
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Yes, the 3K/10W resistors will warm up the chassis pretty well.
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ah alright thanks again..