@ restorer-John: Were you able to swap the diodes? I have several Toshiba-XR-Z70 that have almost the same laser (OPH-32),
several Sony BU-1 based player, a Nakamichi-OMS-5II, two early Denon DCD-1800 plus a Sony CDP-101.
All of them probably have the same diode, Sharp LT 022 MC.
Looks like Sharp was the only supplier at the dawn of the CD-age, also Plilips used this diode
With a friend, we try to find a way to swap the diodes working on the BU-1 and of course the grating is the biggest problem.
He is more technically skilled and tries to develop a tool to adjust the grating. Next problem is the diode itself, LT022MC sources are
not reliable, got 50, maybe 7 were working. So contemporary diodes have to be used, APC has to be altered, the beam spreads differently as well.
But it could be worth for two reasons: Mechanics are rugged and reliable. With a TI Chip, DIT 4096 / DIT4192, the internal Data of the Sony chipsets
(Data / Bitclock /L-R clock) can be convertetd to SPDIF. So if you are not satisfied with the sound, you can hook all the great DACS
from this site to some great Nak, Denon or Sony from the early eighties.
I did this with my Nakamichi OMS-5II player and after some years I even
ripped out the original D/A section and replaced it with a ES9018 based DAC from Twistedpear Audio.
After more than 30 years later, almost all BU-1 based player I own have levels between 0.7Vp-p to 1Vp-p (Level of eyepattern)
One way to squeeze more life out of the diode is to alter the feedback resistor values of the RF-Amp.
This can only be done in any player that uses Sony´s CX20109 RF-Amp and probably others as well.
Later the feedback resistors were integrated in the chip.
By altering the feedback resistor, you can safely raise the incoming signal from the photodiodes
by almost half without adding too much noise. As a result, the power for the laser diode can be lowered.
BTW, someone even gave me the Laser power meter Leader LPM-8000 for free - he said he did not service CD-Players for years...
several Sony BU-1 based player, a Nakamichi-OMS-5II, two early Denon DCD-1800 plus a Sony CDP-101.
All of them probably have the same diode, Sharp LT 022 MC.
Looks like Sharp was the only supplier at the dawn of the CD-age, also Plilips used this diode
With a friend, we try to find a way to swap the diodes working on the BU-1 and of course the grating is the biggest problem.
He is more technically skilled and tries to develop a tool to adjust the grating. Next problem is the diode itself, LT022MC sources are
not reliable, got 50, maybe 7 were working. So contemporary diodes have to be used, APC has to be altered, the beam spreads differently as well.
But it could be worth for two reasons: Mechanics are rugged and reliable. With a TI Chip, DIT 4096 / DIT4192, the internal Data of the Sony chipsets
(Data / Bitclock /L-R clock) can be convertetd to SPDIF. So if you are not satisfied with the sound, you can hook all the great DACS
from this site to some great Nak, Denon or Sony from the early eighties.
I did this with my Nakamichi OMS-5II player and after some years I even
ripped out the original D/A section and replaced it with a ES9018 based DAC from Twistedpear Audio.
After more than 30 years later, almost all BU-1 based player I own have levels between 0.7Vp-p to 1Vp-p (Level of eyepattern)
One way to squeeze more life out of the diode is to alter the feedback resistor values of the RF-Amp.
This can only be done in any player that uses Sony´s CX20109 RF-Amp and probably others as well.
Later the feedback resistors were integrated in the chip.
By altering the feedback resistor, you can safely raise the incoming signal from the photodiodes
by almost half without adding too much noise. As a result, the power for the laser diode can be lowered.
BTW, someone even gave me the Laser power meter Leader LPM-8000 for free - he said he did not service CD-Players for years...