HD83, how to use low and high impedance cans?

Hi, I have built a hd83 some years ago.
I have been using it with a hd600,so it is wired to the
above 250 ohm config.
Now I have bought a pair of sony mdr cd 3000 and
they are 32 ohms.

I want to use both phones with the amp, not at the same time though.

How do I add that function to the amp in the easiest way?
I can think of two ways:

1. Have two headphone sockets on the front, then amp is constantly
wired for two outputs, not sure that is possible, do
not have the schemas here, they are in Ireland, I am in sweden.
Can I wire the output transformers so they are contstanly set up to accept
both 32 ohm and 300 ohm cans, through two outputs at the front?

2. I add a switch, so I can switch the config of the transformers, so I can
switch between 32 and 300 ohm.

since I do not have the schemas here, can someone advise me?
Or point me to schemas?

Cheers,

Claes.

[Mike G]

Hi,

I'm not sure if this will be of use, but if you take a look at the World Designs amplifier kits, and check out the technical information for the HD83 II, you can see a circuit diagram.

I know this is for the mark two version, but I think it was the same circuit for both (just the layout and casework were revised in the later model).

http://www.world-designs.co.uk/acatalog/AmpKits.html

Regards

Mike.

Thanks for the link but that does not solve the problem.
I need the page that has the "wiring" info for the output transformers, they show how to wire the transformer for different impedance cans.

Thanks anyway.

[Little Mick]

Hi

For 16-50 ohms looks like all the secondary are connected in parallel i.e.

0 ohms to blue 1, blue 2, blue 3, blue 4.

16-50 ohms to purple 1, purple 2, purple 3, purple4.


Regards

[John T]

Is this what you're looking for?

P10.jpg

P11.jpg

Regards,

John.

Hey, you da man
Now I just need to figure out how to solve my little problem,
anyone have any ideas if you understand my original description?

Cheers,

Oh btw, can one navigate to these from the world design site as it is now?
I could not find those pics from the HD83 amp II page.