MR71 Tube Tuner alignment

Well, back from Audio Classics with Modafferi mod. done. And great job! Love the tuner now.

One channel not coming up when cold is not an alignment issue!

The first thing I would do would be to test the tubes in the multiplex section to see if any are weak or shorted.

Alignment will affect stereo separation, alignment of the discriminator will affect distortion and where the middle of the signal seems to be, alignment of the IF section will affect gain mostly, alignment of the front end also affects gain and where stations show up on the dial.

If this unit has not been refurbished recently it would be a good idea to replace the filter capacitors in the power supply.

thanks! I think I will send it to Audio Classics for the Modafferi Mod.

Terry Dewick in Knoxville Tennessee. He is one of the foremost experts on old Mac equipment still around. You will have to wait though, he is always backlogged but well worth the wait.

You should give Deltronics a call. They fix just about anything.
Musical Instrument Repair Shop
2911 N Halsted St, Chicago, IL 60657
(773) 549-6635

I don't know about the Chicago area but Audio Classics in New York has a good reputation for refurbishing Mcintosh gear. Try them at www.audioclassics.com.