La-2a point to point with no compression

Hi all,
Ijust finished my second la-2a. the first one works well, and i made this one at the same time with matched components.
The sound is passing well, related to the gain knob..
The peak reduction knob do not make any compression, but if i turn it fully clockwise, i have a saturation with a reduction..
Could somebody tell me which components are involved in the gain reduction ? I swap t4b and tubes with the healthy one, with no results... all wires around the t4b have been checked and are well soldered...

Posting a schematic in the thread will help everyone help you



In this schematic, the bulb is ultimately lit by V4, and the bulb reduces the resistance of the light dependent resistors. Your signal is tapped at the input through R2 to the 12AX7. If you send more signal to the 12AX7, you will light the bulb more. If you send less signal to it, you will light the bulb less.

1) Is your bulb lighting?
If it is NOT lighting:

Check that your signal is making it to the 12AX7's grid and plate(s), and keep tracing the signal (and continuity if necessary) through to the bulb itself.

Check that your bulb is functional. Check its specs to find out the operating voltage and you can feed it that voltage to verify that it lights.

If the bulb IS working:
This is much simpler: Either your LDRs are hooked up wrong, or MAYBE R6 is wrong (either the wrong value, shorted, etc). If the LDRs aren't connected properly they can't reduce the signal. If R6 is wrong, then your voltage divider will only be the source impedance of the input device after the transformer, which will be much much lower than 68K, so the LDRs would have to be reduced to an extremely low resistance to sound like they're having much effect.

stereo adj

check ac volts on 6bq5 plate under compresion

I'm so bad...It was just R3 fully CCW so no comp... turned fully cw and the unit compresses normaly..
Thank you all