Crack Voltage Problem and LED not working [resolved]

DarthBubi

New member
Hi there,

I finalised my build today and was doing the final voltage check. Tubes are glowing fine and the resistance check I did beforehand also checked out. But now the voltages are of like shown in the list below. Also, the LED going from A9 to the centre pin is not glowing. The LED going from A3 to the centre pin is working fine.

T Spec              Measured
1 50V - 100V  147V
2 170V            163V
3 0V                0V
4 170 V          163V
5 50V - 100V  72.3V

6 0V                0V
7 90V - 115V  146V
8 0V                0V
9 90V - 115V  163V
10 0V              0V

I checked for bad solders and found some flaky ones, but this did not change the behaviour. Wire continuity also checked out. Tested every time I soldered a wire. I checked the voltage coming from B8 to A8, and it is 0 what seems odd.
Mains are 220V and 50 Hz. If needed, I can take some pictures of my build.

Thank you in advance.
 
There should be no LED at pin 9, it should be at pin 8.

If you installed it at pin 9 and have nothing at pin 8, the LED may not work properly if you put it back on A8. 
 
You're correct. I accidentally soldered it to the wrong pin. And now it's not lighting up as expected. I need to replace it in order to make it work right or is there a temporary fix, until I have a replacement? Changing the pin did also nothing to the wrong voltages.
 
You can install a temporary wire between A3 and A8 and recheck the voltages on terminals 1 and 5.  The one LED can serve to bias both channels, but ideally you'd replace it eventually.
 
Thanks, this has done the trick for T1. It's now at 74 V. T7 is now also within specs with 99 V, but T9 is still off with 163 V. Can this pose a problem?
I'll get a replacement for the LED ASAP.
 
You have another empty socket hole on a tube socket, this time on the octal. 

Here's leaded solder in Germany:
https://www.mouser.de/ProductDetail/Chip-Quik/SMD2SW031-8OZ?qs=1mbolxNpo8fr37AThVQa6g%3D%3D

I see lots of wires that don't look soldered, so I would order up some leaded solder and be sure your iron is at least 40W, then add a little leaded solder to all the joints when it arrives.  You need to heat it till it flows out and sucks into the joints.
 
That was the one. For the Speedball upgrade, I'll definitely use the leaded solder and rework the joint. I didn't know that Mouser is still selling it. For now, it is working like a charm, and I'm very excited how my HD600s sound with it. Thank you for your help. :)
 
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