My apology if you think it is OT.....
But the major question is still ONLY about the CCS....a part of the SSHV2.....how it should behave when applied as CCS loading a tube...that is all...
Nothing about amps CCS yet......
That part is a classic cascode for CCS, it was around, later I saw it analyzed in Morgan Jones 4th edition book also. A very good book to get, recommended. There is nothing much to it, you just put it where you would put an anode resistor and you turn its trimmer to fix a current. If it will not work that will only be if something is damaged. Good thing its also workable in low voltage so you can model and fix it safely. You can use an Led instead of a tube in that modeling and some 20V supply. Or a small resistor. That's all there is to it.
Thankyou....something more to play with and learn....a nice Christmas gift....
Cheers,
King
king4joy,
To start a new thread, go to the top of this page, click on Amplifiers, then click on Tubes/Valves, then click on New Thread.
Thankyou....I may start a New Thread on "Loading of VT-25A in line amps" later....and see...
Cheers,
King
Back to the SSHV2...
I recently completed a build of the Vacuum State SVP preamp, with an SSHV2 on each channel supplying 250V at about 35mA. In contrast to my previous project, the differential RTP3, the single-ended SVP has almost no power supply rejection, and I am having issues with hum.
Now I wonder (among several other possibilities) whether some noise might be being injected into the sense connections of the SSHV. What is the best way of connecting the two ground connections of the SSHV2? At the moment I have the F0 going to the star ground, S0 to the ground of the phono stage module, and F+ and S+ both going to the HT connection of the phono module.
Should both the S0 and F0 go to the star ground? Might the sense connections S0 and S+ benefit from screening? I should mention that my SVP box is a relatively low EM noise environment, since the PSU is external and the valve heaters are current regulated DC.
Alex
I recently completed a build of the Vacuum State SVP preamp, with an SSHV2 on each channel supplying 250V at about 35mA. In contrast to my previous project, the differential RTP3, the single-ended SVP has almost no power supply rejection, and I am having issues with hum.
Now I wonder (among several other possibilities) whether some noise might be being injected into the sense connections of the SSHV. What is the best way of connecting the two ground connections of the SSHV2? At the moment I have the F0 going to the star ground, S0 to the ground of the phono stage module, and F+ and S+ both going to the HT connection of the phono module.
Should both the S0 and F0 go to the star ground? Might the sense connections S0 and S+ benefit from screening? I should mention that my SVP box is a relatively low EM noise environment, since the PSU is external and the valve heaters are current regulated DC.
Alex
F0 & S0 should connect to the same exact point. Star or other its a specific to a system optimization choice. Keeping narrow loop area between B+ and GND pairs is good for not picking hum in any system. They better be dressed together for most of their run. The sense connections can be carried via a light gauge well twisted pair or coax. It helps in the presence of EMI, RFI, or hum fields.