Hello I have a Audio Note Kits (ANK) Canada Dac 4.1 with tube output stage with two 5687 tubes.
For tube rolling I bought this socket from eBay
"1PC Convert Tube Socket 12BH7 (Top) TO 5687 (Bottom) Tube DIY Adapter Socket"
1PC Convert Tube Socket 12BH7 (Top) TO 5687 (Bottom) Tube DIY Adapter Socket | eBay
After using this socket with 12BH7a tubes instead of 5687 and starting the DAC big distortion in sound started with very little audio signal. The tubes got very hot. I immediately switched of the DAC.
After I removed the adapters and just used my original 5687. Still the same distortion and my tubes got very hot.
Did I destroy the DAC?
Can anyone of tube experts help please?
The Tube output is connected for I think 12volts heater supply to 5687.
So what I need to repair? Is main power transformer burned or I have to change some capacitor?
Thanking you in advance😕
For tube rolling I bought this socket from eBay
"1PC Convert Tube Socket 12BH7 (Top) TO 5687 (Bottom) Tube DIY Adapter Socket"
1PC Convert Tube Socket 12BH7 (Top) TO 5687 (Bottom) Tube DIY Adapter Socket | eBay
After using this socket with 12BH7a tubes instead of 5687 and starting the DAC big distortion in sound started with very little audio signal. The tubes got very hot. I immediately switched of the DAC.
After I removed the adapters and just used my original 5687. Still the same distortion and my tubes got very hot.
Did I destroy the DAC?
Can anyone of tube experts help please?
The Tube output is connected for I think 12volts heater supply to 5687.
So what I need to repair? Is main power transformer burned or I have to change some capacitor?
Thanking you in advance😕
^^^^^ THAT.
And measure and post plate and cathode voltages.
I suspect you lost bias or grid to ground reference because of some poor connection or mismatching and unbiased tubes pass tons of current (all they can), overheat, and operating point goes to h*ll.
All of which matches your symptoms.
Just check what´s suggested above.
And measure and post plate and cathode voltages.
I suspect you lost bias or grid to ground reference because of some poor connection or mismatching and unbiased tubes pass tons of current (all they can), overheat, and operating point goes to h*ll.
All of which matches your symptoms.
What measurement indicates that?
Just check what´s suggested above.
Hello Thank you for your answer. But now I removed the adapter and just put the original 5687 back. Then the sound should be good. But looks like the adpater permanently damaged something a resistor / capacitor or power transformer? I am not so good in trouble shooting. So the wrong tube or adapter changed something?
If you don't feel confident in repairing i suggest you send it to a
qualified technician. And throw those adapters and 12BH7 tubes away to prevent
future problems.
Yes I am going to throw those adapters, they spoiled my nice sounding DAC. Thank you for your advice to send it to a technician.
It does not look like that, by any means.
And you keep asking for magical solutions: finding what´s wrong without actually checking anything.
Probably too thick adapter pins enlarged socket jacks and now you lost contact.
Amazing that you can successfully build 300B monoblocks but do not have a clue how to work this problem.
Solved
Good News as per your tips I checked the heater voltages and plate voltages and the Tube socket Pins. Plate and heater voltages were right . One of the heater voltage pin was very near tube fixing screw so I straightend it .
And somehow now today it works !!!!! Normal. and good sound. All distortion is gone.
Thank you for everybody`s support and tips 😀
Good News as per your tips I checked the heater voltages and plate voltages and the Tube socket Pins. Plate and heater voltages were right . One of the heater voltage pin was very near tube fixing screw so I straightend it .
And somehow now today it works !!!!! Normal. and good sound. All distortion is gone.
Thank you for everybody`s support and tips 😀