Western Electric 437A preamp

[Sunsun22]

I bought a western 437A preamp from a DIYer that sounds excellent. Recently, I installed a low noise regulator and it is even much better than ever. However, there is one problem - the gain is too high that I can hardly turn the volume knob to 9 o'clock position. The DIYer said this is the best set up he has and it is not possible to reduce the gain by not affecting the sound quality. I traced the circuit as follows and would like to know is there any way to lower the gain but maintain the same sound quality?

 

[Miles Prower]

9K attenuator pad in front of the volume control.

 

[Sunsun22]

I forgot to draw a 33K in front of the input with 25K to ground at the RCA socket that I have added. Sorry

 

[Sunsun22]

Revised schematic

 

[Sunsun22]

Forgot the 1M resistor too.

 

[microloook]

Hi Sunsun 22
I am diy guy in HK. You may connect the 25K resistor to the input of attenuator to reduce the gain.

 

[ystkkmkr]

Hi,

How about using Jensen's 4:1 step-down line input transformers, if you do not mind replacing your volume control? I am using jt-11p-1's with a 10k volume control for my 6as7 low mu preamp published by Pete Millett.