Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: fissure on January 29, 2014, 11:46:58 AM
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So i received my Crack and Speedball yesterday and finished building it today. Checked resistances and then plugged it in and checked all the voltages. But they were MUCH higher than they were supposed to be. Only the large tube lit up and the small remained dark. Rechecked all wiring 10 times but could not find any bad leads or connections.
Now i went into the webpage here to look through some posts and looked at the order page also for some reason and thought about the tick box for a 220V transformer... well i just realized i have no such transformer (did not get any power cables at all, but that might be normal?). I was convinced i ticked that box when i ordered and thought to myself that there was some component switched to allow the higher voltage so i never reflected over not having a transformer.
Looking through my the order that was emailed after my purchase i see no such thing as a 220v transformer so i most likely missed it or forgot it (though i now seeing it when ordering)
Now my question is how do i get such a transformer and did i destroy the entire build now when connecting the 220v mains to it ? :'(
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Nevermind, went through the checklist with the package and saw that the transformer is the one in the box and it is checked and have 240V hand written next to it. So it is not an external transformer i assume?
So question now is why my small tube wont light up :/
Is there anyway to test it?
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What transformer are you supposed to have (i.e. what country do you live in?) What is your real name?
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Also, what does the sticker say on the transformer itself?
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Hi there, on the transformer it says 240V Bottlehead PT-3.
I live in Sweden and here we have 220V on the mains. The 6 and 9 on the transformer where it says 150V have 156V out from them so that seems to be okey. Problem is that on 19 i have 156V but then on 21 I have 450V ? Must have wired something wrong but cant find it...
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Hi there, on the transformer it says 240V Bottlehead PT-3.
I live in Sweden and here we have 220V on the mains. The 6 and 9 on the transformer where it says 150V have 156V out from them so that seems to be okey. Problem is that on 19 i have 156V but then on 21 I have 450V ? Must have wired something wrong but cant find it...
So 156V AC comes out of 6/9? What is the AC voltage at terminals 4/5?
19 isn't a terminal with a meaningful voltage on it, so that's worth ignoring.
Where are you touching your black meter probe to perform these measurements? Can you measure the DC voltage between terminals 20 and 21?
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Hi there, on the transformer it says 240V Bottlehead PT-3.
I live in Sweden and here we have 220V on the mains. The 6 and 9 on the transformer where it says 150V have 156V out from them so that seems to be okey. Problem is that on 19 i have 156V but then on 21 I have 450V ? Must have wired something wrong but cant find it...
So 156V AC comes out of 6/9? What is the AC voltage at terminals 4/5?
19 isn't a terminal with a meaningful voltage on it, so that's worth ignoring.
Where are you touching your black meter probe to perform these measurements? Can you measure the DC voltage between terminals 20 and 21?
Sorry i have 159V on 6/9 (on the transformer).
I am measuring with the black probe on terminal 12 fixed between the terminal and the cap leg.
When you say terminal 4/5 are you meaning on the transformer or the front terminal.
4(Transformer)-0V
5(Transformer)-5.2V
4(Front terminal)-343V
5(Front terminal)-303V
20/21-454V
I suspect something is very wrong? :P
Went through the manual yet again and just cant find any wiring error.
Might also mentioned i chose to wire the 4 on the transformer to terminal 14U as it said in the revision in the manual.
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Could you post a pic of the wiring around the transformer?
I can think of a way or two that this might happen, but it's tough to describe it in words.
In any event, we'll get you sorted out.
-PB
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Could you post a pic of the wiring around the transformer?
I can think of a way or two that this might happen, but it's tough to describe it in words.
In any event, we'll get you sorted out.
-PB
Here are some pics on the transformer, sorry about the quality. I placed the AC and line in and out on the backside if you wonder why there are wires going there.
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Here is a couple of more pics.
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Meh i have been measuring AC and not DC. Stupid me.
Still something are not right will post the measurements here.
1 75-90 - 136
2 170 - 151
3 0 -
4 170 - 150
5 75-90 - 135
6 0 -
7 100 - 136
8 0 - 0
9 100 - 136
10 0 -
11 0 -
12 0 -
13 170 - 152
14 0 -
15 185 - 178
20 0 -
21 206 - 203
A1 90 - 138
A2 0 - 0
A4 0 -
A5 0 -
A6 90 - 138
A7 0 -
A9 0 -
B1 90 - 139
B2 170 - 152
B3 100 - 137
B4 90 - 137
B5 170 - 152
B6 100 - 137
B7 0 -
B8 0 -
20/21 - 202VDC
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Starting to wonder if the 12AU7 tube is broken. The 6080 lights up fine but the AU7 tube remains dark and cold and the leds are not lighting up. Tested them both with the black measure point in the center of the socket and the red on each of the pins and then both leds light up. :/
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Set your meter back to AC. Measure the voltage from pin A4 to pin A9. It should be about 6.3VAC. Also measure from A5 to A9. A4 and A5 are connected together so you should get the same 6.3VAC reading. If you don't see those voltages check the connections of the wires connected to those pins and trace them back to check the connection at the other ends too.
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There is a black wire that leaves terminal 12 and heads up to the headphone jack - your amp doesn't have this wire.
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Hi guys!
Doc.B
I just measured the voltages between A4/5 and A9 and i get 5.2V also measured all the way back to the transformer and i have 5.2V between B7 and B8 and 5.2V between transformer pins 4 and 5.
Caucasian Blackplate
I have two wires going out from terminal 12 one connected to U14 and one to the TSR ground pin.
I have a neutrik TSR jack mounted in the wood backside.
Edit: Made some VDC measurements on the power socket and had a bad solder in the socket. Was getting 220VDC instead of 230VDC(Swedish standard) so the 6,3 pin on the transformer now gives 5,6VDC instead of 5,2. Still to low though. Noticed the transformer says 240 volts and since we only have 230 here in Sweden that might explain the lower output on the 6,3VDC tab?
Still not getting the 12AU7 tube to light up though and the voltages on the A socket is still to high. Any ideas?
Cant do any more testing now since i blow the fuse due to some bad measuring on the power socket so will have to go get some new ones.
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Now measure the resistance from pin 4 to pin 5 on the 12AU7 tube. You should get a fairly low resistance reading. If it reads open the heater in the tube is blown.
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Now measure the resistance from pin 4 to pin 5 on the 12AU7 tube. You should get a fairly low resistance reading. If it reads open the heater in the tube is blown.
Hi Doc, so i have read the resistance through all ranges and only get a 1(open) between pin 4 and 5 on the 12AU7 tube. So i guess it is broken? No idea how i managed to brake it though :/
So how do i go about to get a new one now?
Thanks for the help !
Edit: Is there any way to see if its broken visually? Cant see anything loose or that looks broken?
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There is usually no way to see the broken heater wire in an indirectly heated tube like the 12AU7. An email to [email protected] will get a new tube on the way to you.
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There is usually no way to see the broken heater wire in an indirectly heated tube like the 12AU7. An email to [email protected] will get a new tube on the way to you.
So i got a replacement tube locally where i live and plugged it in. This time it lit up fine and the two leds in the socket was working now as well so the tube must have been broken like you said. Everything checked out fine so i went ahead and installed the speedball upgrade but now i have a new issue. I have to high voltages on the right audio channel (i think it is the right one).
The leds on the right PCB is working as they should and terminals 4 and 5 have the correct voltages. But the left PCB is not working as it should, only one LED is emitting light (the right one on the left PCB, looking at it installed) and much weaker than the LEDs on the right PCB so i removed the LED and checked it with the diode tester on my multimeter (or whatever it is called) and i could not get it to light up. The other one i removed as well and tested with the multimeter but that one worked. So could it be a broken LED? I tested them all before installing and they all worked so it must have happened after soldering (can they be damaged from to much heat?). And can a damaged LED result in the weird voltages i am getting?
I also noticed when measuring that both the 150V tabs on the transformer now only delivers 70V. Is this normal?
1 75 - 153
2 170 - 159
3 0 - 0
4 170 - 160
5 75 -82
6 0 - 0
7 100 - 150
8 0 - 0
9 100 - 104
10 0 - 0
11 0 - 0
12 0 - 0
13 170 - 158
14 0 - 0
15 185 - 184
19 0 - 70
20 206 - 0 (should this be 21?) got 203VDC on 21 anways but 0 on 20
A1 75 - 81
A2 0 - 0
A3 1.56 - 1,53
A4 0 - 0
A5 0 - 0
A6 75 - 150
A7 0 - 0
A8 1.56 - 1,53
A9 0 - 0
B1 75 - 150
B2 170 - 160
B3 100 - 150
B4 75 - 81
B5 170 - 158
B6 100 - 104
B7 0 - 0
B8 0 - 0
Regards //John
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The LED was probably OK until it was removed. Unless an LED is visibly broken, we don't advocate removing it.
The issue you describe is likely either a bad solder joint on the center leg of the MJE350 or the wrong resistor installed at R1.
If both LED's on the nine pin socket light, I would think the wrong resistor to be more likely.
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The LED was probably OK until it was removed. Unless an LED is visibly broken, we don't advocate removing it.
The issue you describe is likely either a bad solder joint on the center leg of the MJE350 or the wrong resistor installed at R1.
If both LED's on the nine pin socket light, I would think the wrong resistor to be more likely.
Hi again blackplate, was gonna check it this morning but when i turned it on this morning there was a nice loud crack (pun intended) coming from the powersupply and our main circuit breaker in our apartment released. Unplugged the crack and switched the power back on. Flipped it over and shook it and a tiny piece of solder fell out, this probably was the culprit of the short and i plugged it in again and turned it on. Now all leds are dead but both tubes are glowing. Only getting 6VDC on T1/5 and 225VDC pretty much everywhere else. Including the metal base plate?! So i figured that i unplug it again before i get myself killed :P
Anyways had to go to work so did not have any more time to work with it. My guess is that something have shorted, thing is how do i find it without tearing the whole thing down again.
Edit: Looks like it shorted between the main AC tab on the transformer and the 270 ohm resistor above. Measured it and it gave 265ohm back.
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Ah man forum seems to have been rolled back :( My last two posts are gone.
Anyway to sum it all up.
I have removed the large PCB from the speedball upgrade. And tested with the 6080 removed.
T1 - 75V
T2 - 206V
T4 - 206V
T5 - 195V
Is my new tube broken as well? It seems like the second triode does not draw any power (if this is how it works?)
The two smaller PCBs was removed and resoldered and still the same issue. I switched the boards positions and the problem moved from T1 to T5 instead. Which leads me to belive the issue is with that PCB or an component on it.
The center leg on the MJE350 gives my 195V on the "broken" side and 75V on the left side if that is of any importance.
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The two smaller PCBs was removed and resoldered and still the same issue. I switched the boards positions and the problem moved from T1 to T5 instead. Which leads me to belive the issue is with that PCB or an component on it.
The center leg on the MJE350 gives my 195V on the "broken" side and 75V on the left side if that is of any importance.
Yeah, there's an issue with your smaller PC board. That kind of voltage on the center leg of the MJE350 is nearly always a bad solder joint on the board (or potentially you have a 2N2222A on that board).
Sorry about the forum posts, we are wrapping up some website work.
-PB
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Have resoldered the MJE350 several times without result but will try again. I double checked the two small PCBs and both have the 2907A.
Edit: Resoldered 3 times now and it still does not work.
When the 12AU7 lights up i notice that both of the square metal parts emit light from the top so the heating seem to be working.
But i also noticed two blue glowing things on one side of the tube that seemed to be coming from triode 2 in the tube. But i can not see any such thing on the other side. Just a side note, note sure it is of any importance.
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What's important is that the voltage issue follows one of the boards.
We can send you a replacement board, transistors, and resistors if you like.
-PB
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What's important is that the voltage issue follows one of the boards.
We can send you a replacement board, transistors, and resistors if you like.
-PB
Thanks! But i have ordered replacement parts today for one board from Elfa here in Sweden so i will have the parts on monday don't have the patience to wait +1 week ;P was not more than 10$ anyways. If the PCB itself is faulty i might have to get a replacement but if that's the case i will be in touch, or i might just use a lab board for it.
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Ok so i received some replacement leds a couple of days ago. Replaced the Leds on one of the small boards. Hooked it up and plugged in the power. Now i have 80V on T1/T5 and 205V on T2/T4 so it appears to have been faulty leds that were the problem there (though no visual damage to them).
So i soldered back the big PCB again and hooked it up. Plugged in the Crack again and all leds turned on nice, was gonna measure but then i heard a whizzing sound for a couple of seconds and then a small pop. Turned it of as fast as i could and saw on the big board that the small 31,6kohm resistor had popped and also one of the leds on the board (was visually broken, cracked in half).
Will have to replace the broken components and double check my wiring this time. Any ideas what could have caused this?
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There is probably a solder bridge between two solder joints on the big PC board.
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So just an update on the build. Got some pieces today that i switched (the popped resistor among them) and soldered it back together. Noticed that when i popped the resistor on the big PCB i probably had switched the place of two of the black cables (ooops).
Anyway it is all together now and there is sound ! :D
Sounds really nice in the mid and high end (had a small headroom amp before) though i feel that it is lacking a bit in the low end in comparison, could be a bit beefier. Not sure if the small tube needs to be played in or something (the one i replaced with a new "premium" tube).
There is also zero noise so i am very pleased with that as well.
Thanks for all the help here and for a nice DIY product, was really fun to build :)