It would be worthwhile to use an external transformer… although that’s not the main problem on an 828.
My solution is to try an external 24V DC supply(about 2A rating is OK) and drive that directly onto the power rails.
That means that the phantom power would not operate of course. 
I used a pair of 22V DC supplies, one to drive the mixer and the other (with the -ve to the mixer +22) for the phantom. That works brilliantly.
Hi Ted,
thanks so much for your reply.
I have at the moment a Power supply that it’s able to provide +24V at 2Amps, and has another rail fixed for 48V. I could use this one, just need to put it on an enclosure.
Thanks
I have and 828 with the first discrete preamp version with Belclere transformers, I love the sound of this console and would love to improve it as far as whats possible with nowadays modern components.
When you say “although that’s not the main problem on an 828” are you referring to noise?
What do you feel are the main problems and do you have any tips for possible improvements?
Thank you so much Ted,
it’s amazing to see someone so helpful and dedicated to his products even when something was developed so long ago like the 828, but the fact that theres still so much interest and so many around just proves that it was an amazing piece of equipment.