tgotr Posted July 26, 2019 Report Share Posted July 26, 2019 I have a Sony MDS-501 that seemingly records fine, but when I play back a disc it just gives me bleeps and bloops. I do not have any pre-recorded albums to see if the fault is in the playback, I am scouring ebay for some sampler albums though. I have a video recorded with my phone of what it's doing. It's like the Bleeps and Bloops are the highs of the music I recorded. This is my first foray into the format. VID_20190725_195016[1].mp4 VID_20190725_195016[1].mp4 Quote Link to comment Share on other sites More sharing options...
2many Posted July 26, 2019 Report Share Posted July 26, 2019 That is odd. Seems to be traking continuously along. Never heard one do that before. Do you have another disc to try? Does it do that with others? Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 26, 2019 Author Report Share Posted July 26, 2019 I have three recordables and they all do it. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 26, 2019 Report Share Posted July 26, 2019 Playback of prerecorded is irrelevant. They use a completely different mechanism of data storage - in fact just like a CD, it is 100% optical. Whereas the recordable disks are magneto-optical. You can put that model into DAC mode, right, by pressing record with no disk in? Can you confirm that the sound you are sending to the record input makes it out the other side to the RCA output jacks? If not, I am suspicious of the signal you are feeding to the unit in the first place. Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 26, 2019 Author Report Share Posted July 26, 2019 I tested recording with my CD player connected via optical and analog. It sounded fine whilst recording. The VU meter on the LCD screen looked appropriate too. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 27, 2019 Report Share Posted July 27, 2019 "it sounded fine" doesn't help much. What I want to know is, did the output pins on the MD deck have a good signal in pass-through mode? Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 27, 2019 Author Report Share Posted July 27, 2019 4 hours ago, sfbp said: "it sounded fine" doesn't help much. What I want to know is, did the output pins on the MD deck have a good signal in pass-through mode? I heard the music while it was recording, if that's what you're asking. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 27, 2019 Report Share Posted July 27, 2019 No it isn't. If you don't tell us exactly what you did it's hard to help you, too. I'm suggesting the (correct) sound was never there in the first place. You can test that by listening to the output of the MD deck rather than the input. If you don't know how to do that, please ask and someone less grumpy (than me) may explain. Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 27, 2019 Author Report Share Posted July 27, 2019 ok, I can listen to the output if I put it in DAC mode or put a disc in and press record? Right? I have the output going to my Hifi at the moment. Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 This is the player in DAC mode, switching between both Analog and Digital inputs. I have the player connected to my Hi-fi with Optical if that makes any difference. I've tried with analog out as well, still get good audio in DAC mode. VID_20190727_195038[1].mp4 Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 28, 2019 Report Share Posted July 28, 2019 I agree. That's pretty odd. Too bad you don't have another unit to figure out if it's the playback or recording that got smashed. If you do, simply play that disk in the other unit and if it works we know the playback circuits aren't working, for whatever reason, on your MD. I'm wondering about sample rate errors but you presumably checked all that by recording from line in instead of optical. Is the Onkyo set to anything special? Have you disconnected everything except one component each time (CD and MD for recording, MD and receiver for playback) from both MD deck and receiver? Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 Everything is hooked up directly nothing in-between. It goes from my CD player to MD, to the receiver. I even removed the receiver from the chain and used a cheapo chinese amp hooked up to the line out and some PC speakers, same result. I wonder if the issue is the recording mechanism in some way. Like I mentioned before, it sounds to me that it's catching the extreme highs only. Maybe the unit is well loved and worn out. Maybe all my discs are duds. Maybe I need to adjust something in the machine. Last time I had it opened, it looked like a row of pots were lined up next to the drive. I didn't fiddle with them, not knowing what they were. this is my first and only player. I bought it for $10 on facebook, thinking I could tinker with it because it's a format I've always been curious about. I'd love to get it going. Quote Link to comment Share on other sites More sharing options...
2many Posted July 28, 2019 Report Share Posted July 28, 2019 It is a very nice format and loved by many! As well, many units can be had for a song and a dance if you keep an eye out. Get a sony deck, or a tascam or get a portable for mobile use away from home. then you can test back and forth. Sorry your $10 unit isnt working. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 28, 2019 Report Share Posted July 28, 2019 Just musing on this. Could you post pictures (front and back) of one failing disk? No need to do them all, just the last one that failed which you posted the video of..... Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 Like open the disc and show it? It seems self explanatory as what could you see with the protection closed. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 28, 2019 Report Share Posted July 28, 2019 The outside Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 First four pictures are the same disc. The last disc has five tracks recorded onto it. Quote Link to comment Share on other sites More sharing options...
2many Posted July 28, 2019 Report Share Posted July 28, 2019 Now we are getting somewhere? Out of hundreds of discs I have maybe two that seem to hate being inserted. They fail to read. That’s it, go to another. With those above, at a glance, I notice nothing wrong. What are we looking for? Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 I picked up a newer portable machine on ebay, one that runs on AAs and uses NetMD. I have a few Dedicated WinXP machines sitting around so I am good on the software. Hopefully the seller wasn't being lying in the auction about it working. Quote Link to comment Share on other sites More sharing options...
sfbp Posted July 28, 2019 Report Share Posted July 28, 2019 As OP said he was new to the format, it occurred to me that perhaps they were data discs. So much for that theory. Narrowing things down, it seems that both optical and line in give the same bloops and bleeps, which are duly recorded and played back. Therefore it sounds like the circuitry either in or just before the main ATRAC chip (CXD-whatever). This is a VERY old deck, using ATRAC-2 which is so ancient that most of us have never worked with it. I have exactly one more thought - check the power supply and see if the voltages being delivered to the main board are as advertised. This wouldn't be the first piece of equipment to fail because its PS failed to deliver enough voltage to it. Other than that, I think we're done. Sorry. There are many old decks you can get on eBay for not much money. May I commend to you for example: https://www.ebay.com/itm/Sony-MiniDisc-MDS-JE480-Player-Recorder-MDLP-DECK-WORKS/153560958199 Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 28, 2019 Author Report Share Posted July 28, 2019 I can do that tomorrow. If anyone has the spec sheets so I can check the voltages. Alright I checked the voltages. I could only see three voltages labeled on the board, 12, -12, and 5v. They are all within acceptable variances, at least from what I know from working on computers and other stuff. I still wonder if the Trim pots next to the drive can do anything Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 29, 2019 Author Report Share Posted July 29, 2019 And I burned out the laser. Yea I made it worse. This was my fault, so I can't complain. Gonna call this one a no go, a false start. Like sfbp said, it's an ancient player and it could have been dead before I touched it. If the portable player works out. I'll see into getting another deck. If things work out in my life, I could go head first into this hobby. Minidisc has been a curiosity for me since I was a kid. Nobody I knew had one, and this was the first player I've ever seen. I'd had been this mysterious thing. I don't think this has sullied the format for me, just made it more mysterious. Quote Link to comment Share on other sites More sharing options...
kgallen Posted July 29, 2019 Report Share Posted July 29, 2019 I finally found a service manual for the MDS-501 and some info on those trimpots. All pretty critical to the operation of the unit and not for random twidling! Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 29, 2019 Author Report Share Posted July 29, 2019 well, if it listed the proper resistance, i could try to get back to square one. Quote Link to comment Share on other sites More sharing options...
kgallen Posted July 29, 2019 Report Share Posted July 29, 2019 I doesn't work like that - the resistance setting is based on a set of measurements for each parameter, so there isn't a "proper resistance" - and even if such was provided you've no way to set that, because with the RV in circuit, any measured resistance will be affected by the impedance of the circuitry the RV is connected to (impedance in parallel with the variable resistor). The Service Manual is dated 1994, which confirms the early vintage of this model. Also, given the schematics show many ICs and discrete circuits, it's interesting to see how quickly Sony managed to integrate all of this complexity into the single CXA analogue IC and CXD digital IC device partitions that quickly became the standard architecture in future products. Quote Link to comment Share on other sites More sharing options...
tgotr Posted July 29, 2019 Author Report Share Posted July 29, 2019 Well I've given up on the unit Quote Link to comment Share on other sites More sharing options...
tgotr Posted August 1, 2019 Author Report Share Posted August 1, 2019 I got the portable unit in, it works, and it's giving me the same bleeps and bloops using discs recorded in the 501, so I will assume sfbp was right and the chip in the 501 was bad. Quote Link to comment Share on other sites More sharing options...
sfbp Posted August 2, 2019 Report Share Posted August 2, 2019 Right - it's playing back whatever you gave it, but somehow the input source got gibbled between the connector and the disk when recording. Quote Link to comment Share on other sites More sharing options...
kgallen Posted August 2, 2019 Report Share Posted August 2, 2019 To confirm does a known good disc play back ok in your 501? Hmmm listening back to your videos, it's something really late on in the signal chain given your DA-DA and -DA demonstrations. If you can make a disc in your good unit with 3 or 4 tracks on it, back in the 501 can you do any non-music operation, like delete a track or label a track? i.e. something that tries to write non-music data to the disc. I'm just wondering if the overwrite head or circuitry driving it is dud. If any of these non-music operations do work then the OWH itself would seem ok and we're looking at the music data path somewhere between the ATRAC encoder (IC101), the shock memory controller (IC110, IC109) and the EFM chip (IC103). The digital loopback seems to be an early stage in the ATRAC chip (IC101) so from your AD/DA experiments we're good at least up to there. Sorry if you're bored of this machine now and you want to move on...! Kevin ps The Service Manual/schematics are here - but it's a scanned copy (done ok) so the pdf is about 55MB so it takes a while to download from the site. https://freeservicemanuals.info/en/servicemanuals/download/Sony/mds-501.pdf I've mostly been looking at the block diagram on pdf page 49 and then the ATRAC/SM/EFM chips to the left/upper left on pdf page 52. Quote Link to comment Share on other sites More sharing options...
tgotr Posted August 6, 2019 Author Report Share Posted August 6, 2019 I was able to get a different unit locally (JE440), and it works fine. They said it had trouble ejecting, but I just lubed up the mechanism and it ejects fine. If I had an oscilloscope, I could get the 501 working as a playback only unit, that would be enough as I can just use my NE410 walkman for recording. I have gigs upon gigs of music on my server ripped from my CDs. Be a bit easier than recording like on a tape. Quote Link to comment Share on other sites More sharing options...
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