Restoring Baldwin 40 watt amps

[ratbagp]

I'm at the very early stages of restoring a couple of Baldwin 40 watt amps that Doug Piccard gave me several years back. There is some information about these amps scattered all over the web (including DIY Audio), so I have created a blog to try to bring these together and help me keep track of where they are.

The blog is at Baldwin 40 watt amplifier

Towards the end of the first entry I have some questions I would like some help with, particularly the connection of the choke to ground. Any answers would be appreciated.

ray

[artosalo]

I would like some help with, particularly the connection of the choke to ground.

This connection is a typical choke input filter even though the choke is situated in an unusual place.

Same circuitry is presented in Radiotron Designer's Handbook 4 Edition at page 1163 (fig. 30.1G). Here the choke is also located between ground and the center tap of power transformer.

[ratbagp]

OK thanks. I suspected that it might be a variation of the choke input filter but it did seem different from anything I had seen before.

I've downloaded RDH4 and posted the diagram on the blog.

Thanks,

ray