We stay away from oil and paper caps in our stuff because regardless of the manufacturer, its reasonable to expect that sooner or later an oil and paper capacitor will develop a bit of electrical leakage- and so pass a small amount of DC voltage while otherwise not outright shorting.
Multiple amplifiers shutting down when playing vinyl through a tube phono stage
This has got to be the weirdest audio connundrum, and Ive seen many, I have ever experienced, or even seen.
I have a Balanced Audio Tech VK-P5 phono preamp. It was retubed recently after having the original tubes in there for some 15 years by the previous owner.
I have been using it for 2 weeks since being retubed. My system is composed of the VK-P5 phono preamp, a VK-3iX preamplifier, a Pass Labs amplifier and a digital source.
In that time, my Pass Labs amp blew a fuse. I replaced it and it ran again. 4 days later the fuse blew again. I put the Pass amp aside. I changed the fuse and it started up again. So it still works, but I'll try something else.
Thinking something is wrong with the Pass amp, I replaced it with a very new Audio Research tube amplifier. Twice, the AR amps lights flickered, the sound distorted and bogged down. Being a tube amp, I guess it doesnt blow fuses as fast as the solid state Pass unit.
The amp issues only happens when I am playing vinyl and using the VK-P5. It does not happen with a digital source. As a matter of fact, when the AR tube amps starts to distort and bogged down, the problem stops when I switch inputs on the preamp away from the VK-P5.
Further test were done, I swapped the VK-P5 with a solid state phono preamp, no issues.
I opened the VK-P5 and found 3 of the eight new 6922s to be weak. This was not the case when I tested them for installation.
My suspicion is that something is wrong with the VK-P5, that it is sending a signal/voltage/DC, going through the preamp (how is this even possible?), and then stressing my amplifiers. Oddly the VK-P5 will work and only start having issues 15 to 30 minutes in.
Again, with the VK-P5 out of the system, I don’t have any issues playing vinyl. The system is stable and reliable.
Any ideas to troubleshoot better highly appreciated. Can a ground fault do this? When the amps shutdown, the rest of the stack doesnt even flicker. Ive got streamers, DACs, turntable, both preamp and phono pre dont miss a beat.
I've written Balanced Audio and your input could be helpful.
I have a Balanced Audio Tech VK-P5 phono preamp. It was retubed recently after having the original tubes in there for some 15 years by the previous owner.
I have been using it for 2 weeks since being retubed. My system is composed of the VK-P5 phono preamp, a VK-3iX preamplifier, a Pass Labs amplifier and a digital source.
In that time, my Pass Labs amp blew a fuse. I replaced it and it ran again. 4 days later the fuse blew again. I put the Pass amp aside. I changed the fuse and it started up again. So it still works, but I'll try something else.
Thinking something is wrong with the Pass amp, I replaced it with a very new Audio Research tube amplifier. Twice, the AR amps lights flickered, the sound distorted and bogged down. Being a tube amp, I guess it doesnt blow fuses as fast as the solid state Pass unit.
The amp issues only happens when I am playing vinyl and using the VK-P5. It does not happen with a digital source. As a matter of fact, when the AR tube amps starts to distort and bogged down, the problem stops when I switch inputs on the preamp away from the VK-P5.
Further test were done, I swapped the VK-P5 with a solid state phono preamp, no issues.
I opened the VK-P5 and found 3 of the eight new 6922s to be weak. This was not the case when I tested them for installation.
My suspicion is that something is wrong with the VK-P5, that it is sending a signal/voltage/DC, going through the preamp (how is this even possible?), and then stressing my amplifiers. Oddly the VK-P5 will work and only start having issues 15 to 30 minutes in.
Again, with the VK-P5 out of the system, I don’t have any issues playing vinyl. The system is stable and reliable.
Any ideas to troubleshoot better highly appreciated. Can a ground fault do this? When the amps shutdown, the rest of the stack doesnt even flicker. Ive got streamers, DACs, turntable, both preamp and phono pre dont miss a beat.
I've written Balanced Audio and your input could be helpful.