Hey guys , Sorry I haven"t gotten back to you about my problem but I have gone back to the drawing board and it has taken me this long before I have had any substantial results to report .....
Well I went back and started over again , I used pretty much the same design as before but made sure this time I shielded everything and I used a different power transformer to get 250v DC ......
I actually totally shielded the whole PSU section from the Preamp with 3mm aluminum and used shielded wire throughout and used AC heaters this time and I elevated them to 25v , I also used a a lot of filtering in the PSU , I used CRCLCRCRC filters with about 500uF in the PSU and a 10H choke......
I wired up the first chanell today (2 channel amp) and plugged the output into the High-Z of my PA just to test it and it sounds great , absolutly no hum and no screaming feedback and not muddy at all , I just need to finnish the other chanell then do the tone controlls (thinking of doing a 5 band active eq as I have them allready built from another project) and then hook up the power Amp (stereo 75w per CH) , it"s all going into a 4U case with power amp and EQ section all shielded from each other , it is extreamly cramped in the case .....
So i just wanted to thank everyone who helped me and know that I took all your suggestions to heart and I"ll post back with some Pics when I get it all finnished .......
Thanx
Well I went back and started over again , I used pretty much the same design as before but made sure this time I shielded everything and I used a different power transformer to get 250v DC ......
I actually totally shielded the whole PSU section from the Preamp with 3mm aluminum and used shielded wire throughout and used AC heaters this time and I elevated them to 25v , I also used a a lot of filtering in the PSU , I used CRCLCRCRC filters with about 500uF in the PSU and a 10H choke......
I wired up the first chanell today (2 channel amp) and plugged the output into the High-Z of my PA just to test it and it sounds great , absolutly no hum and no screaming feedback and not muddy at all , I just need to finnish the other chanell then do the tone controlls (thinking of doing a 5 band active eq as I have them allready built from another project) and then hook up the power Amp (stereo 75w per CH) , it"s all going into a 4U case with power amp and EQ section all shielded from each other , it is extreamly cramped in the case .....
So i just wanted to thank everyone who helped me and know that I took all your suggestions to heart and I"ll post back with some Pics when I get it all finnished .......
Thanx