Marantz 4270 DC offset and bias adjustment

The Donk!

2008-02-24 4:48 am
EchoWars said:
Cool. Get 'er tweaked-up and let us know if you can hear an improvement.

Well, I honestly couldn't say. The left channel was all jacked up. It passed signal. Just wasn't being amplified.

After I replaced about 30 parts, for good measure. It just didn't quite sound right.

I actually just finished replacing everything on the amp boards accept for trimmer pots and output coils today.

She sounds great now.

The DC offset is fine.

I haven't checked the bias, because I don't know how.

It's not obvious to me. I see a few ways it could be done.


This is not mine. I am doing this for a friend of a friend, who can't really pay to have it done. Nice guy though.

So, I'd really hate to break it again.

Because I "donated" all the new parts. And can't really do it again!

I can tell you though.

This is one nice unit.

And thanks for the responses Echo.