From Oakley Sound Sent Thu, Mar 8th 2018, 10:52
From Oakley Sound Sent Thu, Mar 8th 2018, 10:52
> Can you explain your last sentence with regards to "grounding R2 and C1"? Sorry, my mistake. My post should read the junction of R1 and C1. Forgive me, I'm not feeling that great right now. So the new 10K resistor needs to go between the junction of R1 and C1, and the unit's 'ground'. Ground is 0V and is connected to earth in this unit. I don't have a CE300 in front of me so I can't tell you where this will be on the PCB. But pin 4 of IC1 will be connected to it, and a whole lot of other things besides, including the sleeve connection of the front input socket. It's probably best to add the new 10K resistor on the underside of the board. What this resistor does is pad down the input by 6dB by shunting excess signal to 0V. What Don's mod does, by reducing R2 to 10K, is shunt the excess signal to the virtual ground reference. This is probably OK but I'm thinking that low frequency signals will cause the reference voltage to shift which could have unwanted effects. The added advantage of adding this resistor is that you don't have to change either R2 or C1. But as I wrote in my original post all this does is reduce the input signal by 6dB which could probably done by simply turning the volume down on the unit sending the input signal. Tony