So, I need some help here. 5 years ago I built an amp modifying a cheap chinese kit. It´s a push pull pseudo triode with e88cc (9622) in the pre and driving stage. Basically its a triode connected "Bevois valley" without the voltage regulator. Its been serving me well for the last five years, and still does. However, I wanted to do the same thing over again, but looking better and with better quality trannies. So that I did a couple of years ago and got as far as populating the PCBs and getting it all in and on a chassi, trannies and all. All that was needed was the connecting. And there it has been lying on my work table giving me a bad conscience. But in these times we all look for something to do, and I got on with the project. Now it´s been 5 years, and other interests has gotten hold of me so I don´t remember everything I did ( and I was probably just following some instructions ) Anyway, I opened up the old amp, and this is where I run into problems. The power supply is on it´s own PCB and there is one ground in and one ground out. The ground from the three prong net cable goes to a ground on the power tranny´s primary. The 0s from the filaments and the secondary is connected to gnd in on the power supply PCB and the gnd out is connected to the amp PCB main ground point which is also then connected to the chassi. If this is the best way to do it or not I could´nt say, but it works. ( and has been working well ) Now my problem; the mains tranny on my new amp has no ground on the primary side. It´s a TRA400 from askjanfirst. There is just a N and 230v. I guess the problem isn´t really a problem if you know what to do, but I don´t trust myself with any guesswork. What should I do? Would really appreciate some help with this. Thank you in advance.
Try grounding the frame of the power trans, along with the chassis, to the ground (3rd prong) of the power inlet.
Post a schematic.
Steve
Post a schematic.
Steve