MC500DS Electronics questions/issues

Log Out | Topics | Search Moderators | Edit Profile

Author Message   Jeffm725 Username: Jeffm725 Registered: 06-2005 Posted on Wednesday, June 22, 2005 - 10:56 am:    Hi, First I want to introduce myself, My name is Jeff and I have been lurking here quite sometime and finally decided to sign up and participate. This is a wonderful place and I look forward to hanging out here. I own a couple of Ibanez guitars with my main stage guitar being a '79 MC500DS I absolutely love it. I paid 300 dollars for it in 1999 (including the original aluminum looking flight case!), after looking for the right 78-82 MC500 for at least 2 years. It was/is in great shape (a couple nicks due to using it on stage for quite a while now) and I would never, ever part with it. The other I own is a red Artist from 85 that was the fourth one made that year (serial approximates A8500004). That one is across the country at my uncles house, I need to get it shipped back. Anyway, I have a question concerning the active electronics/tri-sound setup in the '79 MC500. I believe the tri-sound switches on my year model are set up as up=out of phase, middle=single coil, down=humbucker . Can someone confim this as correct? I have searched threads and have seen conflicting accounts depending on year. The second half of this is that I get some pretty decent (as in bad) buzzing noise when the tri-sound switches are in the middle (single coil?) or up (out of phase?) positions. It seems worse when I am near computer monitors,tvs , lights, but it never really goes away either. The buzz is worst in the up position and pretty bad in middle position, the down position gives the least amount of noise so when I am playing live I am limited to just using this position because I can't deal with the buzz of the other positions. I also really can't use the eq either because that just amplifies the buzz i get in the standard position. So bottom line is all these wondeful tone color options I am supposed to have are rendered useless by this. I can only stay in down position with the eq out of circuit. I am bummed. I checked all the wiring and altough I really am no expert at that stuff, everything looked and seemed okay.I am a tone freak which is why I love my MC but this buzz is killing me. Does anyone have ideas, advice, or similiar experience? I can actually record the buz and post it for download if anyone thinks that would help. Thanks for listening. Jeff   Bobzilla Username: Bobzilla Registered: 02-2005 Posted on Wednesday, June 22, 2005 - 11:10 am:    Jeff, I have a '78 mc500nt. The coil switches function as you described above. There's a bit of noise, but not to the extent that you seem to have. A guitar tech told me to take a pencil eraser and rub it around the wiring cavity where the aluminum (foil?) in the cavity meets the backplate of the cavity/compartment... to cut down noise. I don't know the logic behind it, but I did it. I did not notice any discernable difference between before/after doing that. But, like I said, I don't really have a problem with the noise, it's not bad at all. I don't know where you live, but if you are in New York, I can put you in touch with a great guitar tech here in NY if you'd like. It's a different guy than the guy who told me about the eraser trick, he's very well known here in NY. In any event, there are folks on this site that have far better insight into these things than I. Someone will help you and at least point you in the right direction. Good luck with it, I am sure you will get it straightened out. In the long run, all the circuits in the board can be replaced and that will probably be an option at some point that you may want to consider anyway.   Jeffm725 Username: Jeffm725 Registered: 06-2005 Posted on Wednesday, June 22, 2005 - 8:22 pm:    Bobzilla, Thanks for the response. I am on the Connecticut shoreline so your New York option may be feasible (and I am getting desparate). You know I am just about to try that eraser trick you just mentioned and I will let you know how it goes. There may be something to that because check this out: Last night while investigating it for the 100th time, I took the back plate off and unscrewed and unmounted the circuit board from the backplate. I just left the backplate off and kind of let the unmounted circuit board (and battery) just hang out (onto a pillow ;-) and plugged it in to my jazz chorus and cranked it. There was NO NOISE!!! (Or so little that it was totally tolerable and within reasonable expectation) . God I was happy. So I then remount the cicuit board to the back plate and put it back on and the buzz was as bad as ever. It is like the board mounted to the backplate is acting like an antennae for interference. While checking the wiring I can see no ground or wiring isses or solder problems so I am STUMPED (and disappointed). Thanks again, Jeff

Add Your Message Here Post: -Color- Black Red Green Blue Yellow Purple Orange Cyan Gray White -Font- Arial Courier Symbol Times Verdana -Size- Smallest (-2) Small (-1) Normal Large (+1) Largest (+2) Enter Item number: Username: Posting Information: This is a private posting area. Only registered users and moderators may post messages here. Password: Options: Post as "Anonymous" Enable HTML code in message Automatically activate URLs in message Action: