I will, thanks 
I've also been thinking about building a power supply for the DAC. I have all the parts to build a 2x12V power supply using a 100VA 2x12VAC toroidal transformer. It's a simple design from the VSPS project (Very Simple Phono Stage). Would this vastly improve the performance of the DAC chip?
I've also been thinking about building a power supply for the DAC. I have all the parts to build a 2x12V power supply using a 100VA 2x12VAC toroidal transformer. It's a simple design from the VSPS project (Very Simple Phono Stage). Would this vastly improve the performance of the DAC chip?
I'm reading this thread for quite a while and I would like to make a small contribution.
So far I have done some mods on my 63 KI and I'm very pleased with the result! I've changed the opamps, removed dc-blocking caps and last time I fitted 6 regs (7809 and 7909) to supply the servo drivers and replaced the caps around them.
I replaced C814 with Panasonic FM 3300u. I also replaced C813 with 22000u TSUP, which I managed to fit in place by putting + lead in the hole and to rotate left just as much so it would fit. Then I extended the - lead and isolated it and bent it right to the original - hole.
I've read about the skipping problems Ben noticed when replacing C813 with a much bigger cap, and I think that a possible solution can be placing regs on the drivers. As far as I understand you didn't place regulators, did you Ben? I'm very happy with the 9V regs mod, it is a great improvement in detail. I placed them at R127,R128,R164,R165,R149,R150.
I think I have also an alternative suggestion for the regulation of the DAC supply. I'm planning to place two 5V regulators (with the leds) for the DAC (instead of 4). One for analog 5V and one for digital 5V. I want to remove U164 and U200. Left pin of U200 will be the analog and right pin will be the digital point of supply. Am I right? Or is placing 4 regs much better?
Thanks and greetings, Anton.
So far I have done some mods on my 63 KI and I'm very pleased with the result! I've changed the opamps, removed dc-blocking caps and last time I fitted 6 regs (7809 and 7909) to supply the servo drivers and replaced the caps around them.
I replaced C814 with Panasonic FM 3300u. I also replaced C813 with 22000u TSUP, which I managed to fit in place by putting + lead in the hole and to rotate left just as much so it would fit. Then I extended the - lead and isolated it and bent it right to the original - hole.
I've read about the skipping problems Ben noticed when replacing C813 with a much bigger cap, and I think that a possible solution can be placing regs on the drivers. As far as I understand you didn't place regulators, did you Ben? I'm very happy with the 9V regs mod, it is a great improvement in detail. I placed them at R127,R128,R164,R165,R149,R150.
I think I have also an alternative suggestion for the regulation of the DAC supply. I'm planning to place two 5V regulators (with the leds) for the DAC (instead of 4). One for analog 5V and one for digital 5V. I want to remove U164 and U200. Left pin of U200 will be the analog and right pin will be the digital point of supply. Am I right? Or is placing 4 regs much better?
Thanks and greetings, Anton.
you need to do the other stuff before you start looking at multiple PSU's. This player does respond very well to multiple PSU's and regs especially decent regs but you really need to do the other stuff 1st!
You can always add a separate PSU for the dac later. In anycase, when you've done the bits I suggested, there are a few more local decoupling caps to do then a clock. Then you want separate regs for everything. Thats when you can start thinking about additional supplies.
You can always add a separate PSU for the dac later. In anycase, when you've done the bits I suggested, there are a few more local decoupling caps to do then a clock. Then you want separate regs for everything. Thats when you can start thinking about additional supplies.
Hi Anton! Welcome, and thanks for the info.
You're right, I haven't done the driver regs. So there's 6 of them? Is it possible to do cheapo LM317 regs with LEDs for 9v too? (Let's be honest, I just like the pretty lights. I was very disappointed to read somewhere that blue LEDs are noisier than green).
So you think C813 might be the cause of my skipping after all? I was working on the theory that it was just my laser giving up the ghost, and I'm currently waiting for a replacement. I suppose I could try putting a small cap back on there.
I understand from other contributors that 2 regs for the DAC is the minimum required, but 3 is better. I don't know how much of an improvement doing 4 is over that, but I built two dual boards that snap neatly together back-to-back, so I thought I might as well if I could.
You're right, I haven't done the driver regs. So there's 6 of them? Is it possible to do cheapo LM317 regs with LEDs for 9v too? (Let's be honest, I just like the pretty lights. I was very disappointed to read somewhere that blue LEDs are noisier than green).
So you think C813 might be the cause of my skipping after all? I was working on the theory that it was just my laser giving up the ghost, and I'm currently waiting for a replacement. I suppose I could try putting a small cap back on there.
I understand from other contributors that 2 regs for the DAC is the minimum required, but 3 is better. I don't know how much of an improvement doing 4 is over that, but I built two dual boards that snap neatly together back-to-back, so I thought I might as well if I could.
Nice mods in a good order Anton.
Ben I can't see that the large cap on the + rail for the servo is causing problems! You could always swap back to something smaller and see! Those regs on the drivers are worth doing. If you think about it, the load on those rails can vary from very little to a fair bit for example when the motors start. I don't know why these rails aren't regulated to start. They aren't done in the CD50 and similar either where the older swing arm transport (cdm4) is used and the requirement for instant current is greater in these machines! With an unregulated rail, if the load goes high, the voltage will drop even if it's just for a fraction of a second, it is noticeable.
You could just build a pair of regs to run all 3 chips to start if you wanted??
In my latest 63, I'm running a 160va tx into hexfreds and a couple of 22,000uF audio upgrades SI's then 6 SPowers and local decoupling with ZA. I'm fairly certain there's nothing more I can do in this area
Ben I can't see that the large cap on the + rail for the servo is causing problems! You could always swap back to something smaller and see! Those regs on the drivers are worth doing. If you think about it, the load on those rails can vary from very little to a fair bit for example when the motors start. I don't know why these rails aren't regulated to start. They aren't done in the CD50 and similar either where the older swing arm transport (cdm4) is used and the requirement for instant current is greater in these machines! With an unregulated rail, if the load goes high, the voltage will drop even if it's just for a fraction of a second, it is noticeable.
You could just build a pair of regs to run all 3 chips to start if you wanted??
In my latest 63, I'm running a 160va tx into hexfreds and a couple of 22,000uF audio upgrades SI's then 6 SPowers and local decoupling with ZA. I'm fairly certain there's nothing more I can do in this area
Thanks UV101!
Ben, I agree with UV101 that at least 2 regs for the +10/-10 rails is a good for a starter. I'm no expert at this, but I think that with regulation you can be sure that the supply of the driver ICs is cleaner and steady. Notice that the laser and photodiodes of the disc unit are fed by these drivers, along with the sled motor. I found it easier to fit 6 regs, because the resistors I mentioned can be replaced by them and its harder to find a place for 2 regs, so that they supply all three driver IC's. There's also very little space for the regs, so it can be very tricky if you want to put your own LM317 regs in (if not impossible?). The standard 7909/7809 are cheap as well and they work very well in my player. To be hounest, I'm not sure if special low-noise regs on the driver IC's improve things much further, I'm curious if someone tried both?
I think I place 3 or 4 regs on the DAC as well then, thanks Ben for the advice!
Did you order the new laser unit with a respectable dealer? I bought one VAM1202 at ebay , not even the cheapest one and the seller claimed it was original. It was a fake and it ruined the sound of my player. I even had 'philips' on sticker and PCB. The original VAM1202 is very hard to distinguish from a fake visually. My player had skipping problems as well and that's why I wanted to replace the unit. Now I have put in the original again, after I cleaned it and greased thoroughly with molykote. It works great again, no skipping at all. And the sound of the player is balanced again. In fact my player's laserunit is never replaced and it's still functioning allright.
MKP vs MKT
Hi there,
yes Ray, I was saying stupid things about bass, even if caps were involved
Anyway, i've just changed the output caps, from some F&T MKPs, wich where small and... exactly the same as the Monacor MKTs... (for me they are) in favor of Icel PHC MKPs caps, 6.8µF: is it in my head or do they really sounds louder?
Nino, can you point the eBay links in order to share the seller we have to avoid?
Hi there,
yes Ray, I was saying stupid things about bass, even if caps were involved
Anyway, i've just changed the output caps, from some F&T MKPs, wich where small and... exactly the same as the Monacor MKTs... (for me they are) in favor of Icel PHC MKPs caps, 6.8µF: is it in my head or do they really sounds louder?
Nino, can you point the eBay links in order to share the seller we have to avoid?
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My new laser pickup just arrived. The seller was Liberty Electronics in Miami, US and they have 8k+ positive feedback. It looks to be legit.
I'd like to do the driver regs, but I might need a bit more hand-holding to do it. I'll take a look at those resistors and see if I can figure it out. I don't suppose there's any chance of a close-up pic?
Where do you take the power from for those 9v regs?
I'd like to do the driver regs, but I might need a bit more hand-holding to do it. I'll take a look at those resistors and see if I can figure it out. I don't suppose there's any chance of a close-up pic?
Where do you take the power from for those 9v regs?
These should give you a pointer. I've posted them before. This is the first one I did with driver regs. I used 8v regs so that I could supply them off the original 10v rail. Depends on the drop out of your 9v but if they are LDO (low drop out) they may work. I dont know what the drop out voltage will be for those 317/337 regs you built, but as they are variable, you could adjust them down a bit to suit.
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Dear Ben and Malefoda,
I searched ebay to find the seller I bought the laserunit from. I've found it, but first I'd like to explain a little. I actually don't know for sure that the laserunit I bought was fake, but it didn't have the same quality the original unit had, in terms of sound (very exaggerated highs and unbalanced spectrum). Then I started to read about this, and I discovered there where some minor differences with the original. First of all the original replacement would have the wires and connector attached. Second the rails on the PCB look different, more rounded shape. I'm not sure, but I believe that the sled-motor has a small blue/green dot on it. Maybe that's all nonsense, fact is that it's possible to replace the laserunit with a new one that functions ok mechanically, but sounds horrible, and there all your improvements go! So my advice is at least to listen very good if your cd-player sounds different after replacing the laser-unit. If it does, and greasing the original unit doesn't solve the skipping, maybe the properties I described can help you with buying a good laser-unit that doesn't affect the sound. But I wish for you the new laser-unit is allright ofcourse and I hope I didn't disturb to much! Maybe there are some more people reading this with the same or different experiences with replacing laser-units?
I searched ebay to find the seller I bought the laserunit from. I've found it, but first I'd like to explain a little. I actually don't know for sure that the laserunit I bought was fake, but it didn't have the same quality the original unit had, in terms of sound (very exaggerated highs and unbalanced spectrum). Then I started to read about this, and I discovered there where some minor differences with the original. First of all the original replacement would have the wires and connector attached. Second the rails on the PCB look different, more rounded shape. I'm not sure, but I believe that the sled-motor has a small blue/green dot on it. Maybe that's all nonsense, fact is that it's possible to replace the laserunit with a new one that functions ok mechanically, but sounds horrible, and there all your improvements go! So my advice is at least to listen very good if your cd-player sounds different after replacing the laser-unit. If it does, and greasing the original unit doesn't solve the skipping, maybe the properties I described can help you with buying a good laser-unit that doesn't affect the sound. But I wish for you the new laser-unit is allright ofcourse and I hope I didn't disturb to much! Maybe there are some more people reading this with the same or different experiences with replacing laser-units?
Stage 1 complete - Tested with +/- 15V and 10V @ output.
Brent
An externally hosted image should be here but it was not working when we last tested it.
Brent
Thanks for posting those pics, Ian - that's a big help. I'll need to study the schematic to figure out which polarity goes where, but at least I won't put them in the wrong way round. I can see that the earth pin is soldered to the ground plane on the one - presumably that's the same for all of them that I can't see?
Board's looking great, Brent. Thanks for posting details of the parts you're using, as I have no clue what to get.
If anyone, like me, is building Martin's 'simple but good' 317 reg, I have an interesting data point for you. I've built 8 so far:
- 4 with 10uF + 100uF Elna Silmics and red + green LEDs
- 4 with 10uF + 10uF solid tantalum and 2x green LEDs (as per schematic)
The 4 with Silmics put out 5.2v and the 4 I built last night with solid tantalum all put out a solid 5.02v.
Interesting, huh? I didn't have to change the resistor value or swap in the red LED or anything, and they're bang on.
Board's looking great, Brent. Thanks for posting details of the parts you're using, as I have no clue what to get.
If anyone, like me, is building Martin's 'simple but good' 317 reg, I have an interesting data point for you. I've built 8 so far:
- 4 with 10uF + 100uF Elna Silmics and red + green LEDs
- 4 with 10uF + 10uF solid tantalum and 2x green LEDs (as per schematic)
The 4 with Silmics put out 5.2v and the 4 I built last night with solid tantalum all put out a solid 5.02v.
Interesting, huh? I didn't have to change the resistor value or swap in the red LED or anything, and they're bang on.
Any reason for choosing carbon and not metal film? I've used the metal film ones previously but I've no idea how they compare. Did you go for half watt?