Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: david luckenbach on June 13, 2022, 05:51:58 AM
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i am having issues with install of the speedball
crack was working fine prior to upgrade
9 pin leds not lighting up
voltages are 148, 155,0,170,145 across the board
resistors are fine
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Are both the 12AU7 and 6080 glowing?
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yes, they are both glowing every so often i get a flash of white light from one of the tubes not sure which one as the unit is upside down
also, now one of the 4 leds on the board is out. looking at the board in mounted position-its the one at top right corner
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a9 connection was maybe bad as when i touched that green wire the two leds right side would flicker
i think i got a better solder on that joint now.
but now one led is out as i mentioned above
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Has fixing that joint changed your voltages? Can you post some build pics?
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hope the pics help
voltages today are slightly different 148, 173, 0, 170, fluctuating
so the far right is going up and down
top right led still out
both tubes lit
9 pin leds still both out
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The picture files seem to be empty.
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try these photos
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You have some substantial soldering issues that are going to cause some problems. I would review this soldering video:
https://www.youtube.com/watch?v=EN16Pi7pcfk (https://www.youtube.com/watch?v=EN16Pi7pcfk)
Be sure you're not using lead free solder and also be sure your iron is turned up as hot as possible.
Your joints specifically haven't been heated anywhere near long enough for the solder to flow out and work properly, and this is also true for the solder joints in the underlying build. The exceptions to this (in other words joints to leave alone) would be the power switch and the solder joints for the LEDs, as they take substantially less heat to be properly soldered.
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so basically remove the circuit board and start over.....
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You can reflow all of the solder joints in the amp without removing anything.
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so i found some time to give this a go
voltages on 2,4,7,9, oa, ob and b+ are sill about half what they should be
resistance on 7 and 9, then b3 & b6 are not correct like they used to be
suggestions?
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The resistances on 7, 9, B3, and B6 won't be 3K unless you put the 3K resistors back in.
What's the DC voltage at 13?
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well whatever i did not was mess it up looking at dc voltage at 13
nothing lights up at all anymore, but i do get a flash when i plug in
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What flashes when you plug it in? Is the fuse blown? What DC voltage do you measure at terminal 13?
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well yes i did blow the fuse..
so i replaced the fuse and voltage at 13 was 5.5 dc
it didnt flash this time but now the 2 leds on the tube base stopped working
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If your voltage at 13 is 5.5V there is something very wrong with your amp. Do both the 270 ohm 5W resistors look OK and unburned?
Did you carefully mount the TIP50 transistors as instructed in the manual? If the hardware and insulating pads aren't put on properly, you'll end up with this exact situation.