Improvements in this riaa tube

[widi]

In the circuit there is an elevation of filaments!
It is not bias

Walter

You are absolutely right, I am confused.
I don't know what I'm going to do with this thing anymore

 

[widi]

Some kind soul who can help me

 

[Depanatoru]

The buzz could be because of the way the chassis/box is connected to ground ... how you did it ?

 

[widi]

The buzz could be because of the way the chassis/box is connected to ground ... how you did it ?

Hello, the GNDs are all centralized in the same point located in the RCA connectors and these ground comes from the preamps through the house- gnd that I have attached.

 

[widi]

Finally locate the noise, it was coming from the step - up transformer, it has internal problems with the cable shielding, I will have to replace them.

 

[widi]

I have been thinking that instead of using step - up transformer ?.
Is it feasible to use a 2SK170 for gain as in the schematic I have attached? I only use cartridge MC

 

[widi]

Someone who can help me please

 

[waltube]

try this
run fine

Also with 9 volt battery

Walter

 

[widi]

try this
run fine

Also with 9 volt battery

Walter

Thank you very much Waltube,
I will try according to your scheme,
One question, is the grid configuration of my 6c45p correct?

 

[waltube]

Which is the actual scematic you have?

 

[widi]

Whic is the actual scematic you have?

This is the original

 

[waltube]

The connection is fine.

The Ia of 6C45 is 8 mA
The Vk is around 5 volt

Have you done some measurement on gain and Thd?

The impedance of the output stage is not so low also for a non bypass on 5751.
The output cap is also too low in case a standard input line stage.
Which is the Z in of the line stage?

Walter

 

[widi]

The connection is fine.

The Ia of 6C45 is 8 mA
The Vk is around 5 volt

Have you done some measurement on gain and Thd? I have no means to measure THD

The impedance of the output stage is not so low also for a non bypass on 5751.
The output cap is also too low in case a standard input line stage.
Which is the Z in of the line stage? Around 12K

Walter

 

[Kay Pirinha]

Ist this 10 nF/1 M RC coupling to the 2nd SRPP with a LF rolloff of just 16 Hz intended as an anti rumble filter?
Sorry if this question has been made and answered yet. I didn't read t5he whole thread .
Best regards!

 

[widi]

Or better this way?

 

[waltube]

The line stage which Zin has?
Maybe 1 uF is better if the Zin is 100Kohm
About riaa the 22 nF is better than 10nF but you can put also 100nF