I am going to check the plate resistors tonight, but if they measure identically and DC voltage at the supply side of them is the same...I have to assume something is wrong with the Nutube itself. Since it does sound OK otherwise, clean and quiet, can I change the plate resistor on one channel to compensate? Should I lower the R or raise the L channel to re-balance my output voltage? How do I determine what the right value should be?
Identical input voltages (in AC) can be measured at each component from input jacks to the Grid pins of the Nutube. (with volume wide open). Changing the DC grid bias makes no difference in output AC voltage. Output voltages (in AC) are off from the A pins of tube all the way to output. I have swapped the JFETS (and cleaned the pins), R1 (100ohms in my case), the 1K resistors and the output caps between channels and the problem remains in the right channel. I also removed the right side output cap and still exhibit lower voltage. I have reflowed and sometimes added solder to every pin on the board with no change in performance.
I suppose I could lift the output side of the 1K resistor just to make sure; I don't know enough about electronics to know if or how the downstream parts would affect the voltage reading at the plate.
Process of elimination, I don't know what else it could be. LOL, I don't even know why it would be bad, the tube looks perfect. I have been keeping a log of every AC/DC voltage of each component in the system. Tested at 1KHz, max volume from computer and max volume on B1K to keep it consistent. I sure am glad I used euroblocks on this board!! After this experience I am using blocks on every board I build from now on
I suppose I could lift the output side of the 1K resistor just to make sure; I don't know enough about electronics to know if or how the downstream parts would affect the voltage reading at the plate.
Process of elimination, I don't know what else it could be. LOL, I don't even know why it would be bad, the tube looks perfect. I have been keeping a log of every AC/DC voltage of each component in the system. Tested at 1KHz, max volume from computer and max volume on B1K to keep it consistent. I sure am glad I used euroblocks on this board!! After this experience I am using blocks on every board I build from now on
DIY Audio store should also sell the accessory kit for the NuTube which includes a socket for the tube, to blow easy change-out.
If someone knows what individual socket pins one can purchase to install on the PCB that would accept the pins of the NuTube, that would be appreciated. Of course, this means that some additional stabilization of the NuTube will be mandatory as the pins will raise the NuTube well above the surface of the PCB. Microphony might be a problem....
If someone knows what individual socket pins one can purchase to install on the PCB that would accept the pins of the NuTube, that would be appreciated. Of course, this means that some additional stabilization of the NuTube will be mandatory as the pins will raise the NuTube well above the surface of the PCB. Microphony might be a problem....
I was repairing Falcon Acoustics mini monitors (ls3/5a clones) I built for one of my daughters. Hooked the mini monitors up to my F6 and B1 Korg and got the huge and intimate soundstage that my 300b monoblocks provide on my Altec A5. Great sound. Apparently the mini monitors thought they where being driven by powerful SE triodes, while the Altecs are not as easily fooled ( sound great though
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socket means pushing in
pushing in means force
force on display type tube pins - means trouble