Hello, I have a 6-zone Speakercraft MZC-66 system in my house (came with the house). When connected to an audio source, three zones work great but three others produce a hissing / crackling sound. Int

Try this to isolate where it is coming from. Either the zone amps are defective, which is not likely, or the main amp is at fault. Hard to believe they are mis-wired, they typically are foolproof in this area.

At the main controller, try the two zones that are good and plug them into the 4 bad zones one at a time and see if you get the same symptom. If you do, then it is not the main controller and something common to the 4 zones is causing the issue. If they are wireless, then you my have interference so check if you can select different channels.

e

That's is probably the main IC chip got busted already that causes the hum.
Hope that gives you an idea...

Check to make sure no source or speaker cables cross power cables, and make sure power is clean by using a regulated surge protector.

I repair these:

http://calgary.kijiji.ca/c-buy-and-sell-electronics-Speaker-Craft-MZC-and-BB-Series-Amplifiers-Repair-Service-W0QQAdIdZ229607818

So they never fail again...

simple to program the single keypad to initiate all zones on a single source at a pre set level using the ez tools software

Shame on your Speakercraft dealer for not having installed this system for you or at least telling you how to hook things up! (You did get this from an authorized Speakercraft dealer, didn't you?) As you know, the MZC-66 comes with a 40 page user guide that will show you how to connect the system in your choice of several different ways. You gave very little information as to what keypads you have, what sources you want to connect, or why there is even a standard stereo receiver involved in this picture at all. The MZC is a custom installation product, designed by and for custom installation specialists and it has sooooo many ways to be installed that it can be used in just about any way you might want.
The simplest answer for you right now is that each of the inputs is paired with a "loop-output" which allows you to connect your source first to the MZC, and then (with another patch cord) to another preamp (or in this case, your receiver). You said that you only needed six zones, but the receiver adds in to make seven. Why do you want the receiver in the picture, again? Just for the tuner? Or do you want to use the amplifier in the receiver to power one of your rooms? (Remember, the MZC has pre-outs for every zone!) Depending on what make and model receiver you have, you can do any one of several different methods of making the two units work and play well with others. Again, I go back to the whole authorized dealer thing. With something like this, maybe it's best that you call in a custom installation pro who does this for a living to do this the right way. Too many potential ways to fail in an effort to save a buck. SpeakerCraft dealers are the pros who know how to make these things jump through hoops. They are the ones who put SpeakerCraft at the front of the line in distributed music systems. This is an advanced enough product that there is no way to tell someone the "one" way to make it work. Besides, unless you have just the most basic of keypads, how do you even plan to program the keypads to operate your source equipment? What is it that you want these pieces to do? What keypads do you have? Do you want the keypads to operate the source components? Will you use any of the video distribution functions? Will you use the doorbell or muting functions? How much experience do you have with finessing this kind of thing? Sometimes, it really is best for the DIYer to call in the pros... I just had to call a plumber, myself. It killed me to make the call, but I was wasting too much time and getting nothing done! You should start by calling the SpeakerCraft dealer where you bought the MZC-66. Good Luck!

Check the speaker craft site

The manual is there for download

The fact that you are gettng noise out suggests that the problem is in the "front-end" of the amp. It sounds like the pre-amp section is smoked. What you are hearing is a little distortion that is getting through the pre-amp stage. This can be as simple as replacing a few cheap ICs. I don't know your exact model specifics, but this should be a straightforward repair. Where are you located?

Dan

needs repair

Use your EZ tools and reprogram to make sure the remote stations are getting signal

If you need further help, I’m available over the phone at https://www.6ya.com/expert/craig_3fa289bf857b1a3c