Transformer Wiring Help

Hello, I'm working on a Hohner Symphonic 310 Organ, which I want to restore to it's original specifications, as it was heavily modified by a very sloppy person before.

The power supply had been modified for it to barely work, I suspect one of the original selenium rectifiers blew so they had to replace it with a silicon one, but in the process they bypassed the voltage selector and directly used the 120v mains for a section of the power supply.

Here's the state that I received the amplifier/power supply, as you can see, it's horrible.


now, I've managed to obtain the original schematic from Hohner, and my next step is to restore the power supply, using new components to replace the smelly rectifiers and the old capacitors.
but now I can't figure out how to wire the transformer for the rectifiers.


In the schematic, the 110v and 240v secondaries are shown as independent secondaries, but my transformer has the 110v and 240v secondaries connected in series.

Is there any way to wire my transformer to provide the needed 240v and 350v to two separate full wave rectifiers as shown in the schematic?
I'm not 100% sure but I think the transformer was modified, should I just try to get it rewound or is there way to make it work?
here's a picture of the power supply and amplifier unit after a needed clean, on the bottom left is the transformer in question.


Thanks for the help.

Related notes, advise if you want.

Most importantly, this is a passion project and I'm very much a beginner. I'm aware of the dangers of high voltage and I'm okay with damaging or breaking things in the process, maybe I'm in over my head but I like the challenge.

I'm planning to replace the rectifiers with 1N400X diodes, using dropping resistors to lower voltages where they should be. I'm looking into a solution similar to these, to be able to screw them in place of the old ones so it looks nice.

I think I'll use a 10nf safety capacitor for the "death capacitor" in the primary. Today I was able to find one in a local shop but it's rated for 3kv, is that okay or should I try finding one rated for 400v, or should I just get rid of it and do as this recommends.

I'm in the process of acquiring replacements for the capacitors, I'm just getting new aluminum electrolytics, and probably this for one of the more difficult ones to find. I wonder if I should empty the cans and put the new caps in for a better look, I think if I don't it's going to look too messy for my liking.

About the regulator valves: I'm not sure if they work, as they were also bypassed in the circuit, (which in combination with all the jank made the organ behave in a funny way when anything else was using enough power in the house... like turn on an appliance and the pitch goes down and the oscillators go out of whack and make funny gargling noises.) Is it worth to try to find replacements for the regulator valves, or should I replace them with something else?

I've already posted here asking for help about the reverb unit which is also missing completely, and I'm looking into the options for finding a replacement.
I have attached the full schematic in this post, as it seems to be the only copy of it online, or at least I couldn't find it so I had to ask Hohner.

I'll probably keep posting as things come up in the journey of fixing this thing.


  • Schaltplan Symphonic 310.pdf
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