1. No ad-hominem
2. No spamming or shilling
I use some 25-0-25 EI transformers on the front ends of my mid tweeter amps. Got em from Les W and very nice they are too.
I was only using one of the secondary windings and they have two. Decided to parallel them up and use the whole of the transformer so set about the wiring changes. I then realised that previously I had wired them up wrong I had used the winding start and centre tap from one secondary and the winding start from the second winding.
WTF. It was a total fluke that it worked so well and did not go bang. What a numpty , well at least I have the guts to own up to it here.
I have them wired up correctly now and secondary windings in parallel. Sounds better or maybe I am just expecting it to sound better. Living for the city playing now . Waiting for the bus to drive through my room.
I need to think some more over why that happened cos I like to know these things. Anyway decided to try my 200va single secondary toroids again and see what I think.
Dotted line shows how the 0V connection is made. Seems to me a better idea than just paralleling the secondary windings up. I cant find anything on the net about paralleling two centre tapped windings into the same rectifier bridge .
There is something I like about the EI transformers on the front ends and want to use them if possible even though they are only 100VA 25-0-25 (x2). There is nothing wrong with the sound from the 200va toroids but I have a slight preference for the EI even though they are smaller.
The process is slow but I need to evaluate every change for a while before I am sure of the changes that happen. No inductors in psu for output stage, next stage is to remove them from the front end psu's and then evaluate that. The end goal being keeping it simple if that is what sounds best to me. But I need to go through this slow process of change to really know what is happening.
Currently listening to Bob Marley I find it to be good music for assessing these things.
Snipped some unused 0V wires out of the system today - from unused active preamp boards and old power amp boards. They were still connected to 0V as in my haste I did as little work as poss to make changes. New thicker mains lead on the nva based amps as well.
I already knew that the psu without inductors between the caps for the output stages was going to be better cos i remember the improvement when i did it to the Avondale amps.
Greeted with hum. WTF. Stops when I touch the faraday outer sleeve on the TIS or the plug body with my finger. Does not happen with the Avondale amp. I even reinstated the signal earth connection to safety earth in my cd player but still hums.