Am looking for a working unit or a good unit for spare boards for a local Community Radio Station I volunteer at.

We have a dead Sony MD Player MDS-B4P in which the servo board which drives the spindle motor is cactus.

Not exactly Vintage Radio but am hoping someone on the forum might just know where some of these units are lurking in someones shed and I can track one or more down & sort this one out.

They were widely used in Radio & TV stations a few years back but as digitisation of studios has rendered them obsolete they were pensioned off.

Our station STILL uses a couple in each studio as the older presenters frequently have issues cueing things up using a computer mouse.

We acquired a couple from TCN9 in Sydney & used those to replace some very worn out domestic type units the station initially used and the replacements being broadcast quality are far more reliable than domestic type models.

The sister model to this player is the MD Recorder MDS-B3 which uses the same servo board so either model would be suitable.

We can afford to pay a reasonable amount to get this unit running and into service but like most Community stations we also run on the smell of an oily rag !!

Lindsay

If MD = MiniDisc, I haven't seen one of those for a long time now. They were destined to replace the Compact Cassette but they never took off and Sony then aimed the format at the professional customer. If you know anyone that deals in audio equipment used for rock concerts or in drama theatres you might get lucky.

Brad,

MD certainly IS Mini Disc. I am sure the reason the Cassette won out is that these things are so darned full of complex circuitry whereas the Cassette is so simple and thus VERY easy to service.

I had never seen one until I started at the station about a year ago and was driven batty by the domestic units playing up which was NOT helped by the station having 4 differing models of Sony domestic MD units that did things the same basically with just a few twists to make things interesting.

So when I saw these TCN 9 ones I grabbed them with glee and 2 were OK after some careful cleaning but the third was DOA and after much scratching around with the circuit I have narrowed the problem to the servo board.

The way they work is much the same as a CD player with the record function similar to using CD RW discs.
However the Editing functions and being able to move tracks around leaves CD's for dead and the audio quality is much the same as a CD. The discs appear almost indestructible & can be re-recorded over and over again. As nothing touches the disc surface they never wear out unlike a cassette.

So trying to get a third one up and running for the Standby studio which eases the pressure when stuff clags in Studio 1 and needs fixing I have to wait until we are running on Music Server before I can do anything.

Having the Standby studio fully operational means I can move a Presenter to that studio & dive in get moving on sorting whatever issue has arisen in Studio 1.

Means I will stop tearing my hair out.

Lindsay

A mate of mine once volunteered as a presenter/announcer at 2RRR in Sydney. 2RRR is owned by Ryde Council and back when he was there the two studios were quite ancient by comparison. 33/45 turntables were the mainstay - two per studio plus a tape cartridge machine and half inch reel to reel machine each along with a boom mike and mixing panel in each. A VCR was used to record whatever went to the transmitter as the tape in that only had to be changed three times a day. An old refitted caravan served as an OB van and whilst it was equipped to send its output over a phone line this function was rarely used due to the inconvenience of occupying a temporary phone line back in those days.

I do remember Sony offering a car radio with a MiniDisc deck in place of a tape deck. I am sure a Walkman version was also made. I don't know if the drive mechanisms were the same in domestic and professional gear. If they are then this may be worth exploring too. I don't know if many were sold.

Why not simply use HDD or SSD technology?

It's probably fair to say that most public radio stations operate on very tight budgets. They aren't allowed to receive money from advertising so the owner has to foot the bill for everything. Even when technology upgrades happen the equipment installed is usually a hand-me-down from a commercial station. 2RRR's gear at the time I used to hang around there was stereo but the transmitter was mono so only one channel was used on the mixers and signals from audio sources was combined before the mixing stage. This gave the station a useful backup, should a slider pot cark it, for example.

HDD or SSD technology is cheap (and more so almost every day), readily available, easily duplicated/backed-up, supported by endless audio software products, etc, etc.

Can't see the benefit hanging onto obsolete technology like mini disc. Seems to me as akin to doing video editing on tape rather than disc.

What exactly is "cactus" about the servo board?
We have gear to repair PCBs at component level...,
But would need the machine to diagnose at chip level

Ian,

As far as I can ascertain when monitoring the spindle motor connections when a disc is about to be spun up I see a very brief increase in voltage which then decays away to almost zero.
I would have liked to have tried the board from the other working unit but as that is now in service its a problem to grab it and then disembowel the thing to extract the servo board which is mounted on the rear of the playing unit module.

In hindsight it would have been prudent to do that BEFORE I had removed the old Domestic units and swapped to these 2 Broadcast units. Just did not think it would be anything more than the broken magnet assembly that actually grips the drive centre of each MD to spin them!!

As we are like almost all Community stations money is always tight even though we DO charge for Sponsorship ads but we are limited as to how many we play per hour plus volunteers to get out and chase down Sponsors are not exactly knocking on our doors wanting to do that.
So we are always having one eye on the bank balance.

We got caught out a while back purchasing 2 brand new so called Professional CD players that have proven to be an absolute nightmare in that they intermittently refuse to Eject discs or play the tracks selected or even ingest a disc at times.

As far as the supplier was concerned they could find no faults with either and once the warranty period was over it was then stiff bikkies. I had both on my bench for days trying to replicate the issues but had to agree with supplier.

However stick either back into the Studio and the crazy business starts all over again with no real pattern.
Electrostatic discharge from users was suspected and neither wrist strap or anti static carpet and seat cover treatment had any effect.
As the things are FULL of micros I began to wonder IF they might be getting upset by the WiFi radiation from our router on the rack just a metre away.
Nothing proven so we gave up and we refurbished 5 Denon Broadcast type CD players and put a pair in each studio with one as hot standby and no further problems. The Denons were cast-offs from another Community Station who dispensed with CD's totally and went fully digital and ALL music is on HDD. BUT even they relented and re-installed a turntable in each studio after the presenters jacked up.

We are sticking with MD units, CD's AND I might add even a Turntable as at least half of our presenters are elderly ( as I also am) but they just DO NOT get on with using a computer mouse & prefer to use CD's and LP records and a couple also record their music for a session on MD at home and bring the disc in to play track by track.

As younger presenters come on board we will move towards more computerised music sources. Already a handful of presenters use their Laptops and work from pre setup playlists and that works fine but for the moment we need to keep the older stuff running.

We have our Sponsorship ads on a computer so those who CAN use a mouse do so but we also have the same ads duplicated onto Mini Discs in the studio and they use either.

We have been watching what other stations do as far as going fully digital goes but it appears that fully digital desks are not yet as reliable as our analogue desks. Up to now we are able to fix pretty much anything that goes bung in the desks in house but stations with digital desks have to rely upon the external IT guys to sort it out and it seems that it is not exactly easy to get things back up and running.
There have been a few rather protracted down times for a couple of stations when the digital stuff goes nuts.

Our only down time is when the AC mains fails or the Internet connection fails as the studio-transmitter link is via a Codec running on an Ethernet port at each end to get the 15kHz Stereo feed 3 kms away to the transmitter site.

We are dreading the looming NBN switch over but are ready with a computer at the TX site ready to inject audio straight in to the transmitter when NBN switch over starts as we have 2 ends to do at totally different times.
Having seen what others have experienced we will be glad when its all over but the upside is that we will most likely get a rather good increase in speed both Uploading and Downloading as well have only a 600m cable run to the NBN box inlieu of a 3km cable run back to the Telstra exchange.
Currently we are lucky to see 0.6Mbps UP and 6Mbps Down and because of the poor Upload rate we have to be very careful at the Studio that nobody tries to upload BIG files else our audio starts to stutter as the Codec is forced to heavily buffer what its sending to the TX site.

It sounds like Shite when that happens and does nothing for our image which can impact upon getting Sponsors on board if it is frequent.

I was at an outside concert earlier in the year and noticed that there was no audio desk in a tent propped up mid field. Eventually I noticed a guy sitting in a deck chair in the middle of the audience with a tablet on his lap. He ran the whole show from that. At intermission I sidled over and he showed me the digital mixing desk on it. No snake of cables running from the stage, and associated setup and strike time and labour. Finger tip control of all channels. I asked him about the risk of wireless, etc. He said he has plenty of backup and can run the show from the wings if necessary.

Well I may be able too fix it,
for free I should add. Would just cost you freight, pity you are in WA.

Photo uploaded.

Thanks Brad for uploading the photo.


Ian do you think you might be able to fix this beast as in the first post pic?? I can freight it over & arrange freight back so no cost in that regard to yourself.

The pair I now have in the main studio working are very much liked by the presenters as compared to the ones they replaced which had black faces, tiny labels and weenie buttons. These Sonys are a dream to use especially for older big fat fingers etc.

I have run out of ideas almost..just one to go in trying a 3V supply to the spindle motor to see IF it actually runs as the circuit looks like it has some form of feedback arrangement which is possibly to do with setting the correct speed.

Lindsay

Just a thought. I have seen a C.D. player shut down because the spindle motor was a tiny bit stiff, and the current drawn by the motor was not what the micro expected.

I have also seen an Akai amplifier shut down because its cooling fan, did not run as freely as a new one. (Protection circuitry)

Wayne.

For those who have not seen a mini disc before, here is a picture showing them, together with a DVD for a size comparison.