Valve Itch phono

[merlin el mago]

Bleeder resistor PSU can drop the voltage, I ask because PSUDII can simulate?

 

[Salas]

You should simulate all additional consumptions. If you got bleeder add that to the 10mA the channels themselves need.

 

[merlin el mago]

Have I to add 0.00136mA to CCS so in total 23,6mA?

 

[merlin el mago]

Could be 7,8mV of ripple enough or have I to reduce to 3mV or less?

 

[stajo]

Could be 7,8mV of ripple enough or have I to reduce to 3mV or less?

You will hear it for sure

 

[merlin el mago]

stajo YHPM

 

[Salas]

You will hear it for sure

There is PSRR in the Itch due to the upper valves act as CCSs but he better go for lower ripple.

 

[merlin el mago]

I can achieve 2,5mV or ripple but B+ will be 305V...

 

[Salas]

No problem.

 

[merlin el mago]

I will use two spaced 100mA fast fuses to protect the PSU from the load.

 

[stajo]

There is PSRR in the Itch due to the upper valves act as CCSs but he better go for lower ripple.

I am aware of that but still what gets thru will be enhanced with some 50 dB. I'd go for some split chokes like for example Hammond 155 or 156C in a linear way.

 

[Salas]

If its only to restore the PSU rail for debugging his main circuit problems it does not have to be high class passive cells.

 

[stajo]

In that case I agree.

 

[stajo]

Btw do you still use 4,7uF after SSHV?

 

[Salas]

What you mean, the 22K to 4u7 PP Itch's input stage RC? Yes its there for local decoupling.

 

[stajo]

Ok thanks. I missed the R, surfing on phone. Its also for lowering B+ to input triodes some 60 V?

 

[Salas]

Yes it arranges the proper DC level there too (~25V drop on each channel's RC).
...Are you making an Itch or is it my idea?

 

[stajo]

No I'm at the pub watching football

But I have most of the stuff and its interesting to talk around to get the spirits up.

Just need to force some not that interesting projects in the sea first.

 

[Salas]

And you have a TT? Maybe you told in the 6V6 line pre thread and I don't remember.

 

[stajo]

Is the SSHVs working ok down to 5 mA per channel?