Valve Itch phono

[merlin el mago]

Connected again for warmp up, I will tell you voltage Vin at the reg with Vout 290V

 

[merlin el mago]

What voltage is C1?

In the SSHV2 0.33uF 400V.

 

[merlin el mago]

Only to be clear, actual measurements done with:

-EI core tx 240V
-Cap 1uF 450V at the input reg
-PSU without resitors only rectifiers UF4007 + 2 caps 220uF 450V

 

[Salas]

Does 840 have a pad? Is it live to the sink maybe?

 

[merlin el mago]

Yes have a pad, it's transparent so you can't see, I measued for continuity between heatsink & 840, meter measures no continuity.

 

[Salas]

Lets knock down some resistance on that 47R to see if it draws more. Having another one to solder on top of it?

 

[merlin el mago]

Do you want to parallel other resistor with 47R? wich value?

 

[Salas]

The one 47R you substituted for the trimmer, lets make it smaller by paralleling another one on top of it.

 

[merlin el mago]

For example other 47R in parallel?

 

[Salas]

Yes

 

[Salas]

*When its off and soldering see with the ohm meter that C1 shows no short also.

 

[merlin el mago]

Soldered in parallel other 47R, now TP measures 4,3mA see pic

 

[merlin el mago]

*When its off and soldering see with the ohm meter that C1 shows no short also.

Isn't short.

 

[Salas]

I wonder how it holds regulation with so little apparent CCS current. Is the sink totally cold?

 

[merlin el mago]

Let me power on again, but I remember always cold.

 

[Salas]

Don't power it. It looks like needing lower resistance.

 

[Salas]

Measure TP in resistance mode. What is the reading?

 

[merlin el mago]

powered?

 

[Salas]

No, off for now.

 

[merlin el mago]

7R4