new Brand of Hologram Laser (LDGU) LT0H30PA inside by Philips CDM12 and VAM12 mech

Hi tiefbassuebertr,

I can bring you some clarifications about a few various mechanisms/modules you mentioned:

VAM1201/VAM1202: the VAM1201 had been officially discontinued a long time ago. The VAM1202 had been officialy discontinued a few years ago. It might be possible to find some copy of these mechanisms with very poor performances in terms of reliability compared to the original mechanisms.

VAM1210: there is no VAM1210: you probably refer to the L1210, a complete module (loader+ servo board without DAC section) that makes use of the VAM1202: Officialy discontinued

VAM1250: Philips mechanism which is still in production (look at the latest Vincent CD player)

VAM1205: as far as I know, it had been discontinued a while ago

VAU1252 = CD-Pro, previous version of the CD-Pro2LF (VAU1254/31LF)

CD-Pro, CD-Pro2, CD-Pro2M, CD-Pro2LF/ All the pevious version of the CD-Pro. The latest version is the CD-Pro2LF and is still in production and used by many manufacturers. You can have a look to this link to check the history of this module:
FAQ


I hope it is helpful for you

Thank you for this informations. Now for me the question is, which company produce the VAM1250 and the CD-Pro2LF. If I know this, I can ask there, where selling this company the hologram diode successors from Sharp, that must be automaticlly also still in production (but not by Sharp).
The reason to start this thread was actually the fact, that I get still poor quality concerning CDM12.4 heads (RF-unit TDA1302 integrated) (China copy). If I would get top quality hologram laser diodes in TO-outline, all problems are away for me.
Unfortunately VAM1250 and CD-Pro2LF uses by their laser heads TZA versions (CDRW compatible RF amps). Therefore it is not compatible.
 
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original URL:
http_www_diyplus.net/phpBB3/viewtopic.php?f=3&t=576&start=40



the mentioned URL
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I still hope to get informations about the currently manufacturer of the successor typ from Sharp's LTOH30PA. The CDpro2LF is still in production. Thus also hologram laser diodes must be in production. I am surpriced, how hard to find out it is despite this and various other threads here arround this matter. Where are the experts from Japan, China, Korea, Taiwan and Hongkong?
Especially the suppliers of spare parts from this countries must actually find out this very easy.
 
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Different Sharp's LDGU (hologram Laser Diode) Types - LTOH30PA vs. LTOH30PF

For Sharp's LDGU devices LT0H30PA and. LT0H30PF there still isn't find a data sheet.
But about
http://contents.driverguide.com/content.php?id=67387&path=README.TXT
I read follow:

4.2 LASER DIODE INFORMATION
4.2.1 Laser: Semiconductor Laser, 3 Beam type,
LDGU-Sharp, LTOH30PA for max. 16x speed
4.2.2 Wavelength 780nm typ.
4.4 SUPPORTED DISC FORMAT:
CD-DA, CD-ROM, CD-ROM XA, CD-R, VCD, CD-I, PHOTO CD,
I-TRAX Enhanced CD, CD Extra, Mixed Mode CD & Bootable CD-ROM.


and about
http://contents.driverguide.com/content.php?id=73347&path=README.TXT
I read follow:

4.2 LASER DIODE INFORMATION
4.2.1 Laser: Semiconductor Laser, 3 Beam type,
LDGU-Sharp, LTOH30PF for max 24x speed
4.2.2 Wavelength 780nm typ.
4.2.3 Output Power 0.2 ~ 0.3 mm continuous wave.
4.4 SUPPORTED DISC FORMAT
CD-DA, CD-ROM, CD-ROM XA, CD-R, VCD, CD-I, PHOTO CD,
I-TRAX Enhanced CD, CD Extra, Mixed Mode CD & Bootable CD-ROM.


This means, that the only different between this two hologram laser diodes obviously must be the max possible speed suitability.
Who knows, from which pc cd-rom drive type/model comes this datasheets?
 
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in the attachement the Sharp diodes, from that I need the currently available successor devices in the same outline
 

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  • LT0H30PA=30PAH2ST bottom Ling Hang.JPG
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I bought a couple of VAL1250 units from early Philips production series (remaining stock) for remove the Sharp hologram laser tubes (for replace in CDM12.4 heads of various cd player models, because the usually available replacement CDM12.4 laser heads mostly have very bad quality).
This work is considerably more complicated cause additional mechanical and electrical adjustments of the LDGU, but in the moment the only possibility for the customers with faulty CDM12.4 heads - check the pictures there:
http://www.diyaudio.com/forums/digital-source/118902-stripdown-clean-cdm12-4-a.html

In most cases the Hologram Laser diodes works fine and very reliable with no interruptions (as it should be), but in any few cases are temperature-dependent dropouts are to observe (by breakdown of RF-signal at the same time) above arround 28 degrees Celsius. One can very clearly see the collapse of the RF signal from 1 Vpp to approximately 100mVss.
If the ambient temperature is below 28 degrees Celsius, a perfect playback of CD's without dropouts is possible.

The effect is independent of the manufacturer of the CD player - I watched it on certain models of Thule Audio, Primare, Cyrus, NAD, T + A and Quad - all models where I replace resurrect CDM12.4 heads (old heads with new equipped VAL1250 hologram laser diodes).

What is the reason for this ??
Was the reliability even by the original Sharp hologram diodes not at highest level
(please note, the costs of the VAL1250 head are arround 120 euros) ??
 
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In the meantime I get various CDM12.4 laser heads again.
All ones where is to read "Made in" ... Japan, Malaysia and Taiwan work fine in all respects.

Thus there must actually be a supplier either for NOS from Sharp or good quality copy.

But all CDM12.4 heads "Made in China" (10 pcs) I had to complain cause too low power output.
I must send back all 10 pcs. Thus the hologram diodes from this heads must be a bad copy

None of the wholesalers who buy in the Far East is apparently able to find out, in which factories this parts are manufactured.

Consequently all european (and u. s.) wholesalers purchase always the pig in a poke;
and the Chinese supplier is pleased to have once again sold electronic scrap resp. trash to an European buyer.

Why we have this situation?
Is it because none of the wholesalers resp. large buyers from Europe speaks the Chinese language?
 
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in the meantime I named all compact disc player devices which are not in perfect working condition to electronic scrap in those cases, where CDM12.x/VAM12xx/VAU12xx there are inside - even all very expensive brands like e. g. Krell kps30I, BOW zz-eight, various Marantz and several other so called "High End Audio" products.

there is additional to note, tat the PCM DATA STREAM from an ordinary compact disc provides not a really good sonic quality (only 16bit and 44.1KHz).
 
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Anyone be able to update this info ?

I'm in need of CDM12.4/05 & interested in a reliable source. I've noted the12.4/05 issue of this has yet to be mentioned.

My SFCD-1 has been cleaned way too many X's and needs to be replaced. pc
I know only two possibilities to get high reliability:
1) order a completely unit of VAM1252 mechanism by your local Marantz service department
http://www.diyaudio.com/forums/digital-source/94908-vam-1252-laser-needed.html#post4260281
http://www.diyaudio.com/forums/digital-source/70046-laser-replacement-cd-7-marantz.html
2) replace the hologram laser diode itself - NOS versions of this type are there:
Brand New Sharp LT0H30PA LTOH30PA LT0H30PAH25 LTOH30PAH25 30PAH25T Transistor | eBay
 
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