musicalsari Posted March 23, 2013 Report Share Posted March 23, 2013 Have a problem with recording and wondering if anyone can help! In the last recording I did on my NH700 I noticed internal whirring noises / extended "thinking" sounds which occoured every so often. These have not happened before and I've even gone back through old recordings to check. I've done a few tests and discovered the following: In SP mode: whirring happens at a few seconds into the recording and lasts about 10-15 seconds. It occours throughout the recording at regular intervals which range from 3 minutes to 10+ minutes. These sounds vary slightly in length, and volume. In LP mode: whirring happens at the beginning of the recording and continues for about 45 seconds. It is a loud scary sound, but after this has stopped, no other whirring sounds are recorded. In both modes the recording is picked up throughout, there is no silence or missed bits. It is just that I can hear the machine working and it can drown out the recording. It still plays as normal and seems to be working fine apart from this noise. It hasn't been dropped or sat on and the battery was fully charged. Don't understand why this problem would happen differently in different recording modes? If anyone has any ideas or knows someone who is still willing to fix these awesome things I would be grateful. My minidisc and I have been through alot together and I really don't want to say goodbye any time soon! Quote Link to comment Share on other sites More sharing options...
THIS SUCKS Posted March 23, 2013 Report Share Posted March 23, 2013 try a different disk and try cleaning the laser. Quote Link to comment Share on other sites More sharing options...
musicalsari Posted March 23, 2013 Author Report Share Posted March 23, 2013 Thanks for that advice. I've tried a different disk and the noises are still happening but they are less scary sounding. I'm going to order a cleaner disk off ebay and see if that helps. Quote Link to comment Share on other sites More sharing options...
PhilippeC Posted March 24, 2013 Report Share Posted March 24, 2013 Just some isopropylic (or ethanol 90º diluted by at least 3) drops alcool on a swab and clean the lens gently Quote Link to comment Share on other sites More sharing options...
musicalsari Posted March 26, 2013 Author Report Share Posted March 26, 2013 Used both a recording head cleaner disk and a lens cleaner disc as I don't even know where the laser lens is let alone how to go about swabbing it with alcohol. The problem is better but the noise is still there. I suppose I could live with it and just record in LP. Any other things I could try? Quote Link to comment Share on other sites More sharing options...
jim.hoggarth Posted April 2, 2013 Report Share Posted April 2, 2013 The format used to record tracks is incidental. As far as the hardware is concerned, the signal going to the write head is just a sequence of pulses. The material being recorded or the format has no bearing on the hardware apart from when reading back, as obviously less lossy formats need to be read more often. The whining noise could be caused by an off-centre or bad disc, and using a different disc will often get rid of this kind of noise. Usually this is a high-pitched whistle. Lower frequency noises are usually caused by the tracking and focus servos working overtime, so that the laser object lens oscillates at a near constant audio frequency. This is probably a sign that the laser is in need of a clean, or the laser unit or servo electronics on the main circuit board are on the way out. Another cause of noise is dirt in the optical carriage driving rack and gears. In the case of some models, noticably the MZ-N910, it is caused by the sled drive reduction gear actually jittering as it spins. A characteristic of this sort of noise is that it only screeches when the laser moves in one direction, either outbound away from the spindle motor or inbound toward 'home' position. In your case, the NH700 does not normally suffer from the latter. I would bet a good service and perhaps a part swap would sort it out - could be the spindle motor, sled motor or laser unit at fault, or even the main board - I would have to hear the noise and/or get it on the workbench to be sure. Jim Quote Link to comment Share on other sites More sharing options...
musicalsari Posted August 22, 2013 Author Report Share Posted August 22, 2013 Didn't need to use my minidisc for a while and totally forgot I'd started this thread. Got the player out as I have to record something tomorrow and remembered the problem. I've managed to upload a recording of the noise when it is in SP mode. Long loud sound at the start followed by other sounds every 3 - 4 minutes during the recording. Any suggestions as to what is going on and where to repair them would be received with thanks. I think it is getting a bit older, even in playback it seems louder, and probably needs a service. http://soundcloud.com/dancingrainbowsari/minidisc-noise/s-WzPwh Quote Link to comment Share on other sites More sharing options...
Garten47 Posted January 28, 2014 Report Share Posted January 28, 2014 The format used to record tracks is incidental. As far as the hardware is concerned, the signal going to the write head is just a sequence of pulses. The material being recorded or the format has no bearing on the hardware apart from when reading back, as obviously less lossy formats need to be read more often. The whining noise could be caused by an off-centre or bad disc, and using a different disc will often get rid of this kind of noise. Usually this is a high-pitched whistle. Lower frequency noises are usually caused by the tracking and focus servos working overtime, so that the laser object lens oscillates at a near constant audio frequency. This is probably a sign that the laser is in need of a clean, or the laser unit or servo electronics on the main circuit board are on the way out. Another cause of noise is dirt in the optical carriage driving rack and gears. In the case of some models, noticably the MZ-N910, it is caused by the sled drive reduction gear actually jittering as it spins. A characteristic of this sort of noise is that it only screeches when the laser moves in one direction, either outbound away from the spindle motor or inbound toward 'home' position. In your case, the NH700 does not normally suffer from the latter. I would bet a good service and perhaps a part swap would sort it out - could be the spindle motor, sled motor or laser unit at fault, or even the main board - I would have to hear the noise and/or get it on the workbench to be sure. Jim Hi, regarding the specific noise from the n910 you mention with the jittering gears, is that a harmless quirk of this model, or a fault that should7must get repaired... mine does the same, but seem to work.. for now.. Many thanks Quote Link to comment Share on other sites More sharing options...
SonicFields Posted January 28, 2014 Report Share Posted January 28, 2014 This is a common problem recording with portable MDs, they're prone to generating noticeable noise when writing data to the disc, which is easily picked up by sensitive condenser microphones. You don't mention where the microphone is mounted - avoid microphones which mount directly to the recorder socket. Best practice for field recording is to hold the microphone well away from the recorder or slip the recorder inside your pocket. Best of luck! Quote Link to comment Share on other sites More sharing options...
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