Ave Bona Cornwall Posted October 26, 2011 Share Posted October 26, 2011 Hi, I need some help. I just bought 5 Marantz MA500s and one outputs just a buzz regardless of whether the input is hooked up or not. Does anyone know what is wrong? Is it a simple fix or an expensive fix? I have troubshot the speaker, input, power outlet, etc, and am pretty sure it is the amp, but don't really know anything about the internal workings of amps. Thanks in advance for your help. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted October 26, 2011 Share Posted October 26, 2011 You got a good deal on 4 of those monoblocks. There is one listed on ebay in case you don't get this problem worked out. I have heard that dimmer switches can cause interference and make this happen. Perhaps the shielding in this amp is a little less effective. Quote Link to comment Share on other sites More sharing options...
Ave Bona Cornwall Posted October 27, 2011 Author Share Posted October 27, 2011 You got a good deal on 4 of those monoblocks. I didn't get the California MA500's. I got mine off Audiogon for $100 a piece. So, although $125 each for 4 working isn't awful, I wouldn't have bought them at $125 each. Perhaps the shielding in this amp is a little less effective. I don't think it has anything to do with shielding or interference, since I can't get any music output at all. It is just buzz. Quote Link to comment Share on other sites More sharing options...
mustang guy Posted October 27, 2011 Share Posted October 27, 2011 I need to quit jumping to conclusions. Somebody sure got a deal at $70 each! Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted October 27, 2011 Share Posted October 27, 2011 Unplug it, open it up, and take a look at the wires to the input jack (assuming that it isn't circuit board mounted). The problem "may" be there, although there is much else that could cause the symptom you describe. Quote Link to comment Share on other sites More sharing options...
Ave Bona Cornwall Posted October 27, 2011 Author Share Posted October 27, 2011 Unplug it, open it up, and take a look at the wires to the input jack (assuming that it isn't circuit board mounted). The problem "may" be there, although there is much else that could cause the symptom you describe. Anything in particular I am looking for with the wires? Solid connection? Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted October 27, 2011 Share Posted October 27, 2011 Unplug it, open it up, and take a look at the wires to the input jack (assuming that it isn't circuit board mounted). The problem "may" be there, although there is much else that could cause the symptom you describe. Anything in particular I am looking for with the wires? Solid connection? Yes, look for a solid connection to the center pin of the jack in particular. If you have an old, crappy, speaker you can connect it to, power it up (being extremely careful not to touch any exposed 120 volt wiring from the power cord), and use a straw or piece of dowel to move some of the leads around to see if you hear anything in the speaker. In fact, if you can feed a signal into the amp from a tuner or cd player, you can use this method to determine if moving any wiring results in sound being heard. Quote Link to comment Share on other sites More sharing options...
BluBitRates Posted October 27, 2011 Share Posted October 27, 2011 Check the capictors while you have them opened up. These amps are around 10 years old in most cases so the caps do need to be checked. Also if you smell a rotten egg smell coming from it when it is turned on that can be a sign of a bad cap. Sometimes with these amps too you will hear a buzz through your speakers if you just have the amps on but your source is not turned on. 4 at $125 a piece with a hopefully fixable one for free is not bad. Let us know what you figure out. Quote Link to comment Share on other sites More sharing options...
willland Posted October 27, 2011 Share Posted October 27, 2011 Anything in particular I am looking for with the wires? Solid connection? As much as I love these monoblocks and the big brother MA-700's, the RCA connections are mid level receiver-like, not hex nut bolted on like most good quality amps. Look to see if any cracked soldering where RCA and input wires connect. May just need a touch of solder. Bill Quote Link to comment Share on other sites More sharing options...
Ave Bona Cornwall Posted October 28, 2011 Author Share Posted October 28, 2011 I took the cover off and the RCA input is circuit board mounted, so no loose wires there. I couldn't find any loose wires, and no rotten egg smell either. I have checked different outputs from my receiver to make sure it wasn't the output, and it is not. The output works on other amps, and no outputs work on this amp, but it is that same buzz that you hear if you have the amp on (& hooked to a speaker) with no input coming in. (I felt the panic of hearing this buzz coming from a speaker hooked to a different amp, only to realize 10 seconds later that the RCA cable was not hooked to the receiver. whew!) I did contact the seller, and he said I can ship it back and he will replace it, so, worst case I have to pay shipping to get it replaced. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.