Sjöström Audio DIY forum

Hi,

I'm building a 7V SSR01 using a 9V AC supply, which when rectified and accounting for losses should give nearly 12V output, which should be ok with the SSR01 with AD825 I hope.
The PCB will be partly visible through a perforated cardboard inside an old tube radio, and would like avoid any shining LEDs if possible.

Would it thus be possible just to use a 2.4V zener diode instead of H1, and just leave R3 at 2.2k? Or is the base current of the BC556B negatively affected by this (as I-V characteristics of zeners and LEDs are not the same)
Or would it be possible to even use a 3.3V zener like used as DZ1, possibly lowering the value of R3?

heaveno P-A!

I have been enjoying my QRV-08 for a long time now but I still have not finished enclosure installation with power LED.  I have been afraid of damaging something if I mess up the LED wiring. I understand very little electronics and would not be able troubleshoot if I cause a problem.

I understand how to measure the LEDs I have and calculate the required resistor, however I have not found a specific location on the PCB that I like for the connection.

My friend Keith connected a 1000 ohm resistor to the + side of G31 but I am not comfortable with this location. it is 25V which requires a larger resistor (1500 ohm 2 Watts) and the way I have G31 soldered I have very little space.

Is there a spot you could suggest that would provide 15V and possible is a through the board hole that would be easier to make a good and safe connection.

Thank you P-A I appreciate your help.

Which power supply doesn't work?

Ok, the power supply is not working when i cut the four lines. Where do I go from here?

I'll suggest that you try to get a working power supply first. Then you'll have to cut four traces, the power lines to each amp.

Hi again,

Yes, the electrolytics are mounted correctly.

The supply lines seems to go to a lot of components in the amplifier, could you tell me the part numbers to remove and where to measure the voltage?


Thank you again!

Are all electrolytic caps mounted correctly? Both channels are dead? If yes, then it's not a random error.

The amp was working for a while before it went silent.

Should I disconnect the supply to the psu or the amp? I would guess the regulators behave badly with no load?

I'm trying to get the picture. The amp worked good and then after some time switched off it doesn't and the both channels seems to have the same fault?

I recommend that you cut the supply lines to both channels. Check that you have the correct voltage. 13.93 V is the typical value.

Yes, the resistors are 470k, and the opamps are in the right direction.