Sujet Réduire le buzz du transformateur H3000

First, need to look onto part of H3000 circuit, in part of PSU. There we can see usual design (non impulse type) of PSU to feed digital and analogue parts, So, native transformer distribute 7V-CT-7V AC for digital, and 15-CT-15V AC for analogue. According to circuit, we can calculate rough power of transformers we need - how says rectified DC voltages - 5.2A for digital, and 0.45A for analogue parts. So, like min ~55W and ~18W respectively.
In my case like 60W and 20W.

So, we need to replace native weak transformer with two separate transformers, for each part - digital and and analogue. There only toroidal transformers can be fitted into such humble volume, one over one. I`ve used custom wound transformers.

In my case I`ve used aluminium angle with suitable size, drilling few holes to fasten both transformers, fasten this bracket on lateral side of H3000, holes for new additional fuse socket (green part on pic).

After you`ve installed mechanical parts, you need to connect leads of both transformers, for mains, with two transformers now, and one - through other fuse except native fuse holder on rear panel.
I`ve used also big ferrite coils on mains leads, to supress parasitical noises, usual solution, optional though.

Other low voltage leads of both transformers need to be connected to molex connector on PCB, pins 2, 1(CT), 3, for 15V-CT-15V, repsectively to circuit. As for 7V-CT-7V leads - need to connect to Shottky bridge (CR1), on lateral side of chassis, and +7V DC from Shottky bridge to pin 5 of molex connector, two grey ground leads to pins 7-8.

In fact, not big deal for mid skill tech even, and going in accordance with circuit/service manual for H3000.