Re: Early TX816 capacitors
Mystory solved about the LM strings. From a French book on the MIDI:
"Sauf exception, les quatre derniers octets de cet en-tête identifient en
ASCII le numéro du produit (8387 pour la DMP11, 8976 pour le TX81Z,
etc.), tandis que les quatre premiers, toujours en ASCII, correspondent
aux lettres "LM" (pour LM Division, Nippon Gakki Ltd, participant au
développement logiciel des instruments) suivies de deux espaces."
Translated in english:
"Otherwise noted, the 4 last bytes of the header [of a sysex dump] matches in ASCII the product number (ie. 8387 for a DMP11, 8976 for a TX81Z, etc...), while the first 4 bytes, still in ASCII, are made from the letters "LM" (for LM Division, Nippon Gakki Ltd, one of the protagonists involved into the instrument's software R&D [firmware]) following by two spaces."
So 8950 will be the product number of the TF1, I'm currently looking for a list of all the instruments ID if it exists.
|
Re: Early TX816 capacitors
PSU removed! I'm currently analysing it but it seems to be in perfect condition with no bulged nor leaking capacitors. There was a fair amount of screws to remove for the top cover then the side cover next to the PSU) but actually it was very logical so no much difficulties, at least on this model.
Another interesting thing to note: maybe a coincidence but the PSU (made by Yutaka electric MFG co., LTD) bears the inscription "LM PS NP 80900" (where PS may be power supply and NP 80900 a model number) so LM would reference at least the TX or maybe a Yamaha product line (or "Long Module" or "Large MIDI")?
|
Re: Early TX816 capacitors
Thanks for your answer Takis!
@Daniel: Funny thing, when looking for a voltage selector (there's none on this one) I discovered that the Yamaha stickers reads TX116! It would have been a TX116 with 4 TF1 modules bought as option, interesting, I'll try to get in touch with the previous owner to see if he still has an invoice or something like that.
|
Re: Early TX816 capacitors
Again thank you all for your feedback! AFter looking carefully there isn't a negative stripe so they're definitively bipolar.
Thanks for your answer Bruce I learnt something. I'll stay with the original specs 16V 100?F @85°C.
I think also it would be better.
I did my "homework" Daniel but I'd rather have a second confirming answer since electronics has its intricaties and the language is not as rigorous as the mathematics behind them (even more as the language used for this exchange isn't my native one) : )
No problem, you are right, it’s good to ask to be sure. Not all sources on the net are reliable. I'll be careful with the PSU, thanks for your advice, even if I guess I'm more than prepared for the job since I got few Vectrex capkit under my belt; but one's never too cautious when tinkering with high voltages!
It’s “soft” high voltage, but even so any electric shock is unpleasant.
Also my TX is rated at 100V (12W) and I got a AC to AC converter rated at 110V (100W) since I live in a 230V country, does this 10V difference will do some harm or not??
This shouldn’t be a problem. I have moved to Japan from Europe with lot of 230 V machines, use more big or small step-up transformers, some of them American 110/220, so machines get only 210 Volts and it works well. I thought maybe bigger problem can be frequency - 50/60 Hertz, but even this is OK.
Some TX rack have voltage selector - at least my both have it.
BTW my TX816 has SN 1973, TX416 1428.
Daniel Forro
|
Re: Early TX816 capacitors [1 Attachment]
Thank you for this BIN file and comparison with the other TF1. Great work! Now we can be sure it’s good. Anyway it would be interesting if somebody else can do the same with his TF modules… I haven’t tools and knowledge.
Inside the code the OS version is not written.
Concerning LM 8950, this LM is standard ASCII code header for most of Yamaha SysEx dumps of RAM, but I have never seen it also in the case of OS.
AFAIK nobody knows what LM means. It can’t be the name of designer, as Japanese language doesn’t use L and when converting foreign words they use R. This fact together with general bad knowledge of English here caused more funny things in manuals and schematics, like Moduration - which is their idea how English can look when converted back from Japanese katakana transcription which is “mo-dyu-re-sho-n”).?
My guess is it can be shortage for Load Memory… who knows. Or Lunar Module? Lunch Meat? Loving Mother?
After LM there are usually two empty spaces, and four numbers (different for different instruments and data types) plus two characters describing data type. Sometimes there are not these 4 numbers, but more characters describing data type, and sometimes one number as last in the cases there can be more of such data types.
Of course the number is not a date.
Daniel Forro
toggle quoted message
Show quoted text
Enclosed with this post you'll find the EEPROM DUMP of the TF1 module (I also uploaded it to DX files since many people don't get the emails notification along with the attachments). I read 2 TF1 module from my TX for good measure and they got the same checksum. So seeing few strings here and there (RAM TEST, LED TEST and so on) I think it's a good dump and all the TF1 got the same (unknown) ROM version which seems logical. Funny thing: the header of the ROM starts with the following characters: LM 8950. Either this is totally unrelated or maybe it refers to a date code (50th week of '89, but that clashes with the story about the day one unit of the previous owner) and LM are the initials of the lead programmer, or either that relates to a '85 Yamaha sound chip (). Guess we'll never know : )
_
|
Re: Early TX816 capacitors
Enclosed with this post you'll find the EEPROM DUMP of the TF1 module (I also uploaded it to DX files since many people don't get the emails notification along with the attachments). I read 2 TF1 module from my TX for good measure and they got the same checksum. So seeing few strings here and there (RAM TEST, LED TEST and so on) I think it's a good dump and all the TF1 got the same (unknown) ROM version which seems logical.
Funny thing: the header of the ROM starts with the following characters: LM 8950. Either this is totally unrelated or maybe it refers to a date code (50th week of '89, but that clashes with the story about the day one unit of the previous owner) and LM are the initials of the lead programmer, or either that relates to a '85 Yamaha sound chip (https://en.wikipedia.org/wiki/Yamaha_Y8950).
Guess we'll never know : )
|
Re: Early TX816 capacitors
It would not make a difference since even if the AC amplitude
after the transformer turns out to be higher(remember that's
there's always a ratio not fixed voltages after transformers!)
regulators are going to take care of higher rectified DC input
voltage with the cost of some extra produced heat..
I think that? about + - 10% (don't quote me on the exact number)
of rated input AC voltage will not do any harm as long as
possible? DC regulators are within their input range.
toggle quoted message
Show quoted text
?
Again thank you all for your feedback! AFter looking
carefully there isn't a negative stripe so they're
definitively bipolar.
Thanks for your answer Bruce I learnt something. I'll stay
with the original specs 16V 100?F @85°C.
I did my "homework" Daniel but I'd rather have a second
confirming answer since electronics has its intricaties
and the language is not as rigorous as the mathematics
behind them (even more as the language used for this
exchange isn't my native one) : )
I'll be careful with the PSU, thanks for your advice, even
if I guess I'm more than prepared for the job since I got
few Vectrex capkit under my belt; but one's never too
cautious when tinkering with high voltages!
Also my TX is rated at 100V (12W) and I got a AC to AC
converter rated at 110V (100W) since I live in a 230V
country, does this 10V difference will do some harm or
not?
|
Re: Early TX816 capacitors
Again thank you all for your feedback! AFter looking carefully there isn't a negative stripe so they're definitively bipolar.
Thanks for your answer Bruce I learnt something. I'll stay with the original specs 16V 100?F @85°C.
I did my "homework" Daniel but I'd rather have a second confirming answer since electronics has its intricaties and the language is not as rigorous as the mathematics behind them (even more as the language used for this exchange isn't my native one) : )
I'll be careful with the PSU, thanks for your advice, even if I guess I'm more than prepared for the job since I got few Vectrex capkit under my belt; but one's never too cautious when tinkering with high voltages!
Also my TX is rated at 100V (12W) and I got a AC to AC converter rated at 110V (100W) since I live in a 230V country, does this 10V difference will do some harm or not?
|
Re: DX-100 patch editor / librarian for Mac os 10.7 or 10.9?
Good stuff, Teo.
Is that a keyboard split, two different patches, or just the way one patch sounds in two different ranges?
I've got a bit of a balance problem on the Bach - the left channel / bass is quite a lot louder.? The Scarlatti one is better balanced, for me.
I normally wear my main headphones backwards, so the cable is where I want it, which compounded the problem because my left ear is largely deaf to treble.? It's better when I turn them the way they're meant to be, which puts the left hand / bass notes on the left, but there's still quite a difference - maybe not so much to other people though.
Have you played with keyboard range scaling, in the patch editor?? I tend to adjust that a fair bit because the high notes on FM patches usually sound a lot louder to me, if it's left off (to my right ear, that is).? This seems to have gone the other way a bit.? It probably depends on the listener though, and how good their hearing and headphones are :)
Andy
|
Re: Early TX816 capacitors
Two capacitors In series, back to back, makes sense, yes, Bruce.? I've just been to look for the lash up in question, out of curiosity, but it was a couple of years ago when I made it.? It's hiding.
|
Re: Early TX816 capacitors
Wow! I did not though the topic would get such attention! Thanks to all!
So a bit of mixed answers, audio path or not?
What is so questionable about it? Schematics is the ultimate reference and speaks clearly. These two caps are BP type. Does it make a difference even, since I'll buy (hopefully) official Nichicon replacement (16 or 25V, 105°C and 100?F)?
Just buy what it is: Nichicon or Panasonic 100 uF/16 V, 85 C. Common component, try Mouser, Digikey, Jameco... And what do you mean by bipolar capacitor? A capacitor that as no positive or negative pin?
Uncle Google has a lot of answers, if you ask him:
Do your homework :-)
I will look again at the PCB but I think I saw a negative stripe on the capacitor plastic cover.
I don’t think so.
@pnetops: don't worry I got a eeprom dumper (Genius G540 which worked fine for my DX7 and various other chips) but if you'll stumble upon another one don't hesitate to post it! I think I'll try to dump the eeprom from one of my TF1 (and share it of course), at very least for backup purpose for me
That’s a great idea! Thanks in advance.
@Daniel: does your TX'es got low SN# as well?
I think so, but I can look tomorrow, it’s deeply in one of my rack cases buried in hundreds of cables and now is 2 AM here on this side of the globe… Probably yes, as there were not much of them produced. I'm curious about it because the two DX7 MK1 I owned were different regarding the mainboard PCB : )
AFAIK there were more modifications of DX7, around 14… later versions have much less chips on PCB. Also about 11 changes of OS. And don't worry about the PSU, actually that was the first thing I wanted to look at but infortunately it's not the easiest to dissassemble compared to thye TF1 modules (4 screws). I'll try again tonight.?
As I said, it’s a nightmare. Not only to get it out, but then disassemble the PSU box itself, and get out the PCB. If I remember well, there are four screws with short distance pipes (? I don’t know exact term), some nuts are hidden inside and difficult to access them…
Be careful, three biggest ?caps on primary side are high voltage (rated to 400 V), they can be loaded. Before touching anything around them unload them first by shorting their pins.
Daniel Forro
|
Re: Early TX816 capacitors
A bipolar capacitor -- often called 'non-polar' -- is a special type
of electrolytic.? Standard electrolytics are, by design, polarized:?
they act like a capacitor with voltage applied in one polarity; and
pretty much like a (bad) short circuit in the other polarity.? Since
it's possible to make smaller electrolytics at a certain {capacity *
voltage} compared to say, mica or ceramic types, they are used in
applications where the voltage on one side may go both higher and
lower than the other side -- ex: the output of an amplifier like a
headphone amp -- where a regular electrolytic isn't suited to the
job.
Most non-polar electrolytics are really two capacitors in one
physical package arranged like so:
? ?? ?? +?? -?? ?? -?? +
??? -----||----------||-----
In either direction, one of the capacitors is acting as expected,
and the other one is a short.? Although bigger in size, one could
just as easily buy two 'regular' electrolytics and solder the (-)
terminals together -- that's kind of what the factory does, just
more elegantly.? You may find that the specific replacement value
needed isn't easy to source.
These devices are mostly used in audio circuits that require a large
combination of capacitance and working voltage.? I've *never* seen
one used as a bulk cap in a power supply.? Be careful:? in an audio
circuit, the power-supply maxim of "more is better" doesn't always
apply.? More capacitance will both increase the low-frequency
response (good) and the peak current and startup/settling time of
the circuit (maybe, not as good).
Regards,
-BW
Bruce Wahler
Ashby Solutions.com?
bw@...
978.597.7008
toggle quoted message
Show quoted text
?
Wow! I did not though the topic would get such attention!
Thanks to all!
So a bit of mixed answers, audio path or not? Does it make
a difference even, since I'll buy (hopefully) official
Nichicon replacement (16 or 25V, 105°C and 100?F)? And
what do you mean by bipolar capacitor? A capacitor that as
no positive or negative pin? I will look again at the PCB
but I think I saw a negative stripe on the capacitor
plastic cover.
@pnetops: don't worry I got a eeprom dumper (Genius G540
which worked fine for my DX7 and various other chips) but
if you'll stumble upon another one don't hesitate to post
it! I think I'll try to dump the eeprom from one of my TF1
(and share it of course), at very least for backup purpose
for me
@Daniel: does your TX'es got low SN# as well? I'm curious
about it because the two DX7 MK1 I owned were different
regarding the mainboard PCB : )
And don't worry about the PSU, actually that was the first
thing I wanted to look at but infortunately it's not the
easiest to dissassemble compared to thye TF1 modules (4
screws). I'll try again tonight.
|
Re: Early TX816 capacitors
I thought I saw a negative stripe too, but it's the manufacturers name - stupidly positioned to look like one.
I haven't seen the service manual, but no doubt that's right, so what Daniel(?) said (sorry - losing track) - they're bipolar capacitors, in the audio path.
|
Re: Early TX816 capacitors
Wow! I did not though the topic would get such attention! Thanks to all!
So a bit of mixed answers, audio path or not? Does it make a difference even, since I'll buy (hopefully) official Nichicon replacement (16 or 25V, 105°C and 100?F)? And what do you mean by bipolar capacitor? A capacitor that as no positive or negative pin? I will look again at the PCB but I think I saw a negative stripe on the capacitor plastic cover.
@pnetops: don't worry I got a eeprom dumper (Genius G540 which worked fine for my DX7 and various other chips) but if you'll stumble upon another one don't hesitate to post it! I think I'll try to dump the eeprom from one of my TF1 (and share it of course), at very least for backup purpose for me
@Daniel: does your TX'es got low SN# as well? I'm curious about it because the two DX7 MK1 I owned were different regarding the mainboard PCB : )
And don't worry about the PSU, actually that was the first thing I wanted to look at but infortunately it's not the easiest to dissassemble compared to thye TF1 modules (4 screws). I'll try again tonight.
|
Re: Early TX816 capacitors
+1 -- on both counts!? :-D
Regards,
-BW
Bruce Wahler
Ashby Solutions.com?
bw@...
978.597.7008
toggle quoted message
Show quoted text
?
I think they're [bi-polar or non-polar capacitors]
probably two normal electrolytic capacitors back to back
in the same can, in parallel (with positive of one
connected to negative of the other and vice versa).? I've
done that across a small DC motor with two normal
electrolytic capacitors (for strange reasons of my own)
and they were fine - they both survived putting it into
reverse.? If you do that with just one electrolytic
capacitor,? it tends to explode when it's reverse biased -
I've done that too, though not on purpose :)
|
Re: DX-100 patch editor / librarian for Mac os 10.7 or 10.9?
Total preliminary tests but I like to share.
These are TOTALLY unedited and full of mistakes.
The Bach Air you see I'm experimenting with sustain pedal on the organ side, to get an effect.
The Scarlatti, well I always do those types first time dry - no sustain - 2nd time with sustain pedal. I have a piano recording of that Scarlatti - and also my Bach Air - where I always do AABB the first times "dry" - not a word understood by pianists but we know what I mean, then the 2nd time the sustain allows amazing dissonances.
I haven't had time to work with and record the new sounds I've found, I've only gone through maybe 2/3 of the banks I found, the ability to organize them is really nice though!
I hope it's appropriate to share these totally unfinished at all pieces. I like the fact they are totally left and right channels so sorry if you are missing a speaker!
May these gifts shared be taken with the same vibe they are shared with.
Teo
|
Re: Early TX816 capacitors
Yes, bipolar capacitors in that sense are electrolytic.? So, they may well have a rating in AC, or just in volts, without the DC.
I think they're probably two normal electrolytic capacitors back to back in the same can, in parallel (with positive of one connected to negative of the other and vice versa).? I've done that across a small DC motor with two normal electrolytic capacitors (for strange reasons of my own) and they were fine - they both survived putting it into reverse.? If you do that with just one electrolytic capacitor,? it tends to explode when it's reverse biased - I've done that too, though not on purpose :)
|
Re: Early TX816 capacitors
I expect you're right about the rating, but the point is, electrolytic capacitors don't last forever, and can't reasonably be expected to.
I can think of two pieces of equipment in my life, off hand, that routinely suffer severe capacitor failure.
One is the Casio DH-100.? They are notorious for just one particular capacitor failing.? I bought one already failed that way (knowingly), and replaced it with a tantalum bead, which I hope will last longer.
The other is a TV recorder box, I own, which I sent to be repaired to someone who has a lot of experience of repairing that particular model - actually, he just replaces all the electrolytics in the power supply, so I didn't have to send the whole thing. I could have done it myself, but I'd far rather pay someone who's good at it, and has the experience, if the price is fair.
In both cases, they are clearly not specified to withstand the conditions they routinely encounter, and in the case of the Casio DH-100, it was just poor design - the capacitor presumably overheats, but due to too much current going through it.
In the case of the TV recorder, they probably did their best given that it's a small enclosure that generates quite a bit of heat from a RISC CPU and an IDE hard drive.? Apparently, mine had lasted longer than most, and most likely, it will fail again, in few years, or a sooner.?
The capacitors probably didn't reach their rated temperature, but the heat still shortened their life, because they were at a good fraction of it for long periods of time.
I'm sure Yamaha's engineers did a good job, and the insides of synths are normally not that hot.? Still, capacitors are normally the first thing to fail.? Depending on the circumstances, that can be sooner or later, but it's pretty much inevitable.
Andy
|
Re: Early TX816 capacitors
Drying electrolyte on the other hand can cause internal capacitor
resistance to rise leading to higher cap temperatures under normal
operation but in that case we already have a? failing or soon to
fail cap.The fact that it can withstand its "failure" makes it no
less failed.(I could've said that better, I know;))
Even if a cap is designed to last more under temperature stress,
capacitors that reach that kind of temperature marks are probably
already due to be replaced.
It's just less probable to fail in a spectacular or leaky way.I
believe that's the principal reason people use higher temp caps in
consumer stuff.They usually fail "quieter" than standard caps but
that doesn't prevent from drying.
One can argue though that higher temped caps might have better
electrolyte formulas to begin with.I'm no cap expert though, so I
can't tell for sure.
toggle quoted message
Show quoted text
?
You may as well know that, but the service hours are
stating capacitor lifespan in hours worked under the rated
temperature.
At 85 celsius this may or may not be alarming but for 125
rated caps it's almost impossible for a cap inside
consumer equipment to "see" that kind of temperature.
I've yet to encounter equipment that reaches 70 or more
ambient temperature so the caps internal temp is not easy
to reach even 85 celsius most of the time.
Also ,the majority of chips usually have max operating
temperatures far lower than the capacitor temp ratings so
under extreme circumstances the caps are tested for, even
if the capacitor can withstand this kind of heat the
machine would probably fail anyway because of the chips
not operating correctly.
That's why it is typical to find caps thousand hours
older than the 1 or 2k hours one sees in the datasheets.
Caps are temperature over-rated for most consumer
applications.(all that applies to quality caps not the
chinese junk you see everywhere these days)
?
Well spotted.? I missed that.? They may well be
bipolar.
Are there just two?? Maybe they are for the headphones
socket.
What looks like a marking for the negative lead isn't
- it's the manufacturers name.
But, yes, electrolytic capacitors do wear out.? It's
one of the main reasons old equipment dies.? If you
look at datasheets or suppliers listings, you'll
normally see an alarmingly short lifespan, rated in
thousands of hours - and often only one or two
thousand.
Andy
|
Re: Early TX816 capacitors
Further knowledge can be found in the Service Manual :-)
Modern caps are smaller than old ones so the size is no more problem. There are even very small caps available (more expensive). 105 grades are more expensive.
Daniel Forro
toggle quoted message
Show quoted text
They are most likely dc decouplers. The safest way to go without further knowledge is to replace them with the same value caps. What is important is the uF value (especially if they do filtering), the voltage (bigger voltage tolerance is ok, but the larger the voltage the larger the capacitor, this can be an issue if they are on a fairly packed board), and the temp rating is basically inconsequential for most things, i.e. there are only usually two ratings, one is for 'commercial', the other is sometimes referred to as 'military' grade. So choose 100uF, 16v or 25v and 85c or 105c if they are similar price.?
|
AndyHornBlower
Givnology Wellness Arts