My k4004b works just fine. I have build it in to a classic tube amp radio with a pair of car speakers and it sounds great!
The problem is that I use a iPod nano 4 as a source. I use the headphone as output/input. But each time I connect or disconnect the iPod there is an unhealthy crack thru the speakers. Ho do I solve this? I have search the Internet but you find what you search but I think I am not asking the right question.
I also like to ad a potentiometer between the signal to give the old tube amp radio back some of it function back. I mabye on the wrong track but I did some reading on decoupling caps.
I hope there is someone to shed some light on this. The finished product will be a gift and I want it to be a good gift without killing any iPod, amp or speakers…