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Sony MXD-D5C Minidisc Recorder / 5 CD Changer deck, modified for TOSlink optical digital output

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Inspired in large part by Admin Stephen sfbp's about adding an optical digital output to his MXD-D40 Minidisc Recorder / CD Player Combo deck, I have finally begun the project to "fix" the Achilles's heel of my eleven-year-old Sony MXD-D5C Minidisc Recorder / 5 CD Changer deck by adding a TOSlink optical digital output:

EDIT 2011/10/27: How-To guide

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Well, great news - I now have fully operational discrete digital CD and MD Optical and Coaxial digital outputs! Yes FOUR digital outputs - Optical and Coaxial for CD, and Optical and Coaxial for MD. Overkill, yes, but now I have maximum flexibility for connections. Still wish I could mix both CD and MD devices to one connector, but hey, this is the next best thing, right :)

Here's a nice little kicker - NO SOLDERING* to the deck required, I was able to tap each +5V, GND, SPDIF0, and SPDIF1 circuits from ribbon connectors inside the deck. SPDIF0 and SPDIF1 signals came from the audio board CN305 (pins 1 and 3) as described before. +5V and GND comes from the Mainboard "For Check" Connector CN800 (normally unused, I was able to easily tap pins 1 and 6). Pretty cool methinks. Of course, *soldering is still required to build the circuits for output.

I still have to mount everything to the back panel, and I have a couple differing ideas. I think the trickiest part is flush-mounting the square TOSlink transmitters (how do you drill a square hole, LOL). I may use my earlier idea of cutting small "X" shapes in the sheet metal and folding in the corners to reveal a square hole. I'd like everything mounted to a sub-panel that can be easily detached from the back of the deck, we'll see what I can work out.

More details to come...

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The good news - this project is all but buttoned up. All the wires and connections have been cleanly organized, the digital output connections on the rear panel of the deck are mounted and look nice, all four digital outputs are operating nominally, and music sounds terrific.

However, I have been QC'ing the audio output (via Sony STR-DB1070 Receiver, Bose 701 II speakers, and Sony MDR-V500 headphones) and am noticing that for the first fraction of a second the music is silent or muted for some CD and MD tracks that start suddenly with, for example, a big beat or sudden note at the very start of the track. It is probably 0.25 seconds before the music cuts on from silence, often missing the first drumbeat or partial note of the song, but then plays wonderfully from then on. Careful listening using the headphone jack directly in the MXD-D5C deck reveals that the tracks do not start late, they are normal, and this is also true when using analog outputs to receiver. It think it is not so much a problem with the deck mod per se, but could be my receiver getting a "late start" to each new digital track - is this normal receiver behavior with digital inputs? At least one CD with tracks that are "megamixed" together plays normally from track to track, without gaps or hiccups, but CD's with distinct songs are cut off at the first fraction of a second (enough to easily notice). In fact, when using the coaxial output, the receiver briefly displays "PCM 44.1khz" at the start of each track, indicating to me some sort of break in the digital PCM stream as a CD or MD plays from track to track.

Thoughts?

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Is that "Yes it's the receiver" or "Yes it's the digital connection regardless of the receiver"? lol. It also clips the first moments of a track when using the optical output, but the receiver display remains steady on the input name, without showing "PCM 44.1khz" like it does while using the coaxial connection. If I repeatedly skip back to the beginning of a track, sometimes a bit less is cut off from the start; it seems a bit random. It's the same sort of instantaneous muting the the receiver does as I dial through audio inputs - it takes a split second for the sound to get output through the speakers. Some sort of noise/static/pop attenuation?

I suppose I could connect the deck to my sound card, hit record, and see what the waveform shows as I play from track to track...

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Yes, I've seen this. I've seen it mostly with the (A/V) receiver, but also when I used to have an optical->coax converter for playback into my computer.

I just did a little test with PC->D40->Receiver. Playing stuff in SonicStage.

The first time I start, the setup kills off the opening seconds of the music. But If I now jump around from track to track I always get the whole thing. Including if I jump back to the track I started with.

It's some sort of setup thing. Probably the reason that CD's like to have 2 seconds of silence. The flip side to this is maybe no track marking when you try to record, if the signal doesn't actually drop at all.

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Yes, I've seen this. I've seen it mostly with the (A/V) receiver, but also when I used to have an optical->coax converter for playback into my computer.

I just did a little test with PC->D40->Receiver. Playing stuff in SonicStage.

The first time I start, the setup kills off the opening seconds of the music. But If I now jump around from track to track I always get the whole thing. Including if I jump back to the track I started with.

It's some sort of setup thing. Probably the reason that CD's like to have 2 seconds of silence. The flip side to this is maybe no track marking when you try to record, if the signal doesn't actually drop at all.

After further testing, I have discovered that it is in fact the 2 seconds of silence between tracks that is causing the trouble with my receiver. I can see the digital signal indicator on the receiver display drop away for a moment as the silence between tracks is played, and when the next track begins playing, the receiver is not quite fast enough to play back the first instant of music when the signal returns. It happens whether the connection is optical or coaxial.

Would a different receiver deal with the return from 2-second silence any better? Or is there another workaround, maybe SPDIF signal fed into another SPDIF In -> SPDIF Out box of some sort?

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You could feed it back into the digital in, set that to be the MD recording input, and then press "REC". TBH that's what I've been doing all along.

Quick question: what is LS(T) set to?

Is it possible this value is

a. non-default (out of the box should be -50dB)

b. being used by the electronics to mark the tracks when it sees a level drop

Maybe set it (press Setup 2x and rotate until you see it) to very low (-72) or very high (0), or maybe disable Level Sync altogether? I haven't modded my deck yet, so maybe this is a reason (for me) to go ahead.

There may be somewhere else in the circuit that comes before that, and is not subjected to level producing effectively a track mark. I have noticed that getting a track mark out of my PCLink box is eminently possible, but that the same sounds played straight from the PC optical out on my audio card never give me a track mark. So it's a function of what produces the signal, more than it is a function of the signal (ie. CD in this case) being played.

Stephen

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Just a quick note, I did the optical out thing on my new D5C. Not quite the same as camron, but near enough. It works, and since I have to put it in MD REC mode to get the digital signal, that assures a constant stream to the receiver, and there's no problem missing the start of tracks.

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You could feed it back into the digital in, set that to be the MD recording input, and then press "REC". TBH that's what I've been doing all along.

Just a quick note, I did the optical out thing on my new D5C. Not quite the same as camron, but near enough. It works, and since I have to put it in MD REC mode to get the digital signal, that assures a constant stream to the receiver, and there's no problem missing the start of tracks.

Well, if I set the MD to REC mode using the internal CD->MD circuitry, connect the MD digital output to the receiver, and play a CD - I still have the problem with the beginning of a song clipped in it's first moments.

However, if I use my new TOSlink output from the CD side and plug the other end of the same cable into the MD TOSlink input, play a CD, and set the MD REC input to Optical In - The CD immediately stops playback :/ (The deck is "smart" enough to know that you won't need to play back a CD while an MD is recording from an external source, and stops the CD as soon as the optical input setting is selected.)

Quick question: what is LS(T) set to?

Is it possible this value is

a. non-default (out of the box should be -50dB)

b. being used by the electronics to mark the tracks when it sees a level drop

I'm afraid I don't know what LS(T) means... sounds like a digital level adjustment or track mark detector? I will try the steps you've outlined, however.

Thanks for your input, as always!

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It probably stands for Level Sync (Trackmark). It's the level at which a recording MD knows that we want a track divide automatically when Level Sync is set on.

We'll get to the bottom of this eventually. I know that some devices seem to care about level drops in the source and some don't, when transmitting.

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I opened up the MXD-D5C user manual to jog my memory on these Setup Level and LS(T) functions. I've made all the adjustments I could in these menu settings, but I still am getting the same results. I really do think the receiver is to blame - I played the same CD I had been testing with the D5C on my DVD player, connected via TOSlink, and was still getting the head of the same songs clipped after the 2-second space between tracks. Clearly, it is not the sole fault of the deck. Hoping a different receiver in the future may solve the issue.

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Well, if I set the MD to REC mode using the internal CD->MD circuitry, connect the MD digital output to the receiver, and play a CD - I still have the problem with the beginning of a song clipped in it's first moments.

Odd. Take a look at page 46 first paragraph (of the amplifier's manual). Looks like maybe Sony knew this was sometimes a problem.

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Odd. Take a look at page 46 first paragraph (of the amplifier's manual). Looks like maybe Sony knew this was sometimes a problem.

Thanks for spotting that in my receiver's user manual. I spotted these settings, too, after spending some quality time with the user manuals of both the MXD-D5C and the STR-DB1070. Unfortunately, after experimenting with the D.Power and V.Power settings, there was no difference in the reaction time to the start of a song after the 2-secong gap between tracks.

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I would like to start the detailed build how-to with lots of photos. I could do this a couple different ways, though my preference would probably be by adding to/editing this current thread. Is it possible to slightly edit the title of this thread? Say, from "Sony MXD-D5C Minidisc Recorder / 5 CD Changer deck, modified for TOSlink optical digital output" to "How-to: MXD-D5C Minidisc Recorder / 5 CD Changer deck, modified for TOSlink optical and Coaxial S/PDIF digital audio outputs".

Should I begin the how-to from the next post, or edit post #1 to become the full how-to? I don't know if there is a line limit to text and photos, I expect it would be fairly long and detailed.

I could start a fresh new topic if that would help keep things cleaner.

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I suspect you may be able to edit your own topic titles. If not, just make a new one and make a link from here. However your suggested title is probably too long.

How about "Sony MXD-D5C Minidisc Recorder / 5 CD Changer deck, modified for digital output (Coax + Optical)". If i need to change the topic title I know I can.

Stephen

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  • 1 year later...

The good news - this project is all but buttoned up. All the wires and connections have been cleanly organized, the digital output connections on the rear panel of the deck are mounted and look nice, all four digital outputs are operating nominally, and music sounds terrific.

However, I have been QC'ing the audio output (via Sony STR-DB1070 Receiver, Bose 701 II speakers, and Sony MDR-V500 headphones) and am noticing that for the first fraction of a second the music is silent or muted for some CD and MD tracks that start suddenly with, for example, a big beat or sudden note at the very start of the track. It is probably 0.25 seconds before the music cuts on from silence, often missing the first drumbeat or partial note of the song, but then plays wonderfully from then on. Careful listening using the headphone jack directly in the MXD-D5C deck reveals that the tracks do not start late, they are normal, and this is also true when using analog outputs to receiver. It think it is not so much a problem with the deck mod per se, but could be my receiver getting a "late start" to each new digital track - is this normal receiver behavior with digital inputs? At least one CD with tracks that are "megamixed" together plays normally from track to track, without gaps or hiccups, but CD's with distinct songs are cut off at the first fraction of a second (enough to easily notice). In fact, when using the coaxial output, the receiver briefly displays "PCM 44.1khz" at the start of each track, indicating to me some sort of break in the digital PCM stream as a CD or MD plays from track to track.

Thoughts?

After further testing, I have discovered that it is in fact the 2 seconds of silence between tracks that is causing the trouble with my receiver. I can see the digital signal indicator on the receiver display drop away for a moment as the silence between tracks is played, and when the next track begins playing, the receiver is not quite fast enough to play back the first instant of music when the signal returns. It happens whether the connection is optical or coaxial.

Would a different receiver deal with the return from 2-second silence any better? Or is there another workaround, maybe SPDIF signal fed into another SPDIF In -> SPDIF Out box of some sort?

1-year-plus BUMP

Happy to report that after recently upgrading to a Yamaha RX-A1020 A/V Receiver, I seemed to have SOLVED the problem of the first moments of a track being cut off before audio begins! W00t!

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