Versatile and comfortable passive pre-amp

[atupi]

Did you tried a Philips remote control. For example sometimes i use my Philips cd player remote control. The kit is designed for Rc 5 Philips codes.

 

[meanman1964]

I did try that too even other brands,I only need a remote from someone which does work .So i'm certain there's nothing wrong with my board.
Could there be something wrong,how can I test that?

 

[atupi]

Did you checked carefully connectivity of Ir sensor ? Use also sensor datasheet and check the 5v voltage on ir sensor pins.

 

[meanman1964]

I've 5 volt on the board connector and as soon I connect the Tsop it drops down to 1,5 V

 

[meanman1964]

Problem solved,wrong wiring TSOP

 

[atupi]

Good to hear that !

 

[meanman1964]

I soldered the pcb connector the wrong way around and cause of that I always wired the TSOP the wrong way

 

[meanman1964]

I maybe can make mine public

It happens very soon just give me some time

 

[meanman1964]

Help,
Want to adjust the imbalance but I don't measure any resistant on the LDR's

UPDATE : Problem solved all fine know,removed Jumper 2

 

[meanman1964]

Soft Power on board doesn't work voltage is there

 

[meanman1964]

I do have a constant voltage on my VCpre board at the soft start board connector even when I put my VCpre board in stand-by modus

 

[Rudi_Ratlos]

Patrick, the "Standby-Mode" only switches off the 230VAC mains voltage on the Soft-Power-On PCB, but it keeps the voltages, needed operate the Pre from a remote-control-unit.
Also: in "Standby-Mode" all relays and the backlight of the LCD are switched off; so the power needed in Standy-Mode is very, very small (<10mA).

Best regards - Rudi

 

[meanman1964]

How come I don't hear the relais of the soft start clicking?Is the status LED needed to let it work?

 

[Rudi_Ratlos]

Patrick, the status-LED is needed to provide voltage to the base of the transistor that switches the relay's coil on and off.

Rudi

 

[meanman1964]

You also told me to put a 10K resistor inline of the LED right?

 

[Rudi_Ratlos]

Patrick, I have sent you an EMail.
Rudi

 

[meanman1964]

Thanks

 

[wineds]

Since I have finished my VCPre I have always had concerns about the channel balance, Tongiht I verified a very simple way to get the channel balance set precisely.

First make sure the VCpre is operating correctly and is functioning like a potentiometer. Mine emulates a potentiometer of about 4K ohm resistance. Next feed a DC voltage to both L and R inputs simultaneously (I used +5V VA from the VCPre test point but you could easily use a battery as well).

Finally connect one DVM probe to the L OUT and the other to the R OUT. Set the DVM for low mV range (say 200mV FS). Then adjust the balance trimpot for zero. You will find this only holds for one attenuation setting of the VCPre But I found that it held fairly close to zero over the range I listen.

This made a huge difference to the spread and precision of my system sound stage. Very happy with the end result! Thanks once again Rudi for you great work!

 

[meanman1964]

Softstart is working now I used 2n5551 instead of BC548 and it was needed to turn the 2n5551 around 90°

 

[meanman1964]

Now I don't understand nothing anymore : I hear and feel the relais of the softstart clicking but no connection at all.I don't get any voltage at the output