Been some time since I posted a project and this one is a good one to show off. I received this Marantz 3200 preamp for some restoration work and really like the compact design and layout of the unit. When top and bottom cover are removed the power supply, protection, and phono preamp are easily visable next to each other. The Preamp or tone board as Marantz likes to call them is foil side up under a black cover towards the front of the unit. For simplicity I removed the faceplate and unscrewed the tone slides to access the board. A combo of Nichicon high temp PW, Panasonic FC, and Panasonic stack film were used throughout. In the preamp section two bipolar elec caps were replaced with Nichicon ES BP caps, notice the bright green. Also, on the preamp a few tantulums were replaced with Nichicon low noise KL.

Transistors in the preamp and phono sections were replaced with Fairchild semiconductors which were matched well. The only adjustment to be made is checking supply voltage of 75vDC at pin J806 of the power supply and adjust with the trimmer as needed.

Power Supply

image

image

Protection circuit

image

image

Phono preamp

image

image

Preamp

image

image

All cleaned up

image

One Response

  1. … Oh, and by the way, I just got news my McIntosh tuner is ready to be shipped.

    Now, McIntosh Authorized Service never gave me a written estimate on my MC30s or the tuner, despite months of inquiry. I was never given estimated finish dates, either, or told when I might expect delivery. I wasn’t even told about any issues on my 1955-era equipment during repairs, just left in the dark. And this crap has gone on ever since last October, over many emails and phone calls.

    About a month ago, McIntosh gave me two days to come up with $1200 for my amps, without any warning, even though when I first ordered the repairs we discussed that I’m retired, living on a fixed monthly income, and need time to get such sums. More recently, McIntosh wanted $775 for the tuner, again without warning.

    Worse, the soldering on my amps when I get them reminded me of stuff we did back in electronics tech when we were first learning — dull and gloppy, with vacant tiny bubbles.

    On the other hand, you, sir, have closely held to your estimates despite various setbacks, kept me up to date on any issues, requested advice on my preferences, and, though delivery have dates indeed slipped, it was never without adequate notice. I was also able to see your quality work on the photos on your website, so there won’t be any sad surprises on that score.

    Now, I intend, at this point, to continue the restoration, over time, of the MC30s. (Though I might do some of it myself.) (Or at least run down any hard-to-get required parts.) And I also realize you’ve already warned me you might not be that interested in beginning such a large project, at this time.

    But before I talk to anyone else about that, you can be sure I’ll get in touch with you. And not McIntosh.

    Sandy