By removing phenolic base board between player and sand box, I observed similar results as with my previous player. That board didn't work well in that location. I will check how the transport sounds in it's original form, on suspension. Any idea what to use to make suspension even softer (with res. at 2 Hz)?
I just placed 1/4" thick damping material between metal base of a player and sandbox. The sound is more open, maybe slightly less bass, but more pleasing tonal character. I almost got it where I wanted.
One more construction picture showing the regulators and connections. I used small video sockets for 6 wire control link for easy disconnecting. Four wire plug was used for power supply. The heat sink for two regulators is just right in size.
Tonu,
Does removal of a DAC brings any sonic improvement? Are you also using red stby button for new disc?
One more construction picture showing the regulators and connections. I used small video sockets for 6 wire control link for easy disconnecting. Four wire plug was used for power supply. The heat sink for two regulators is just right in size.
Tonu,
Does removal of a DAC brings any sonic improvement? Are you also using red stby button for new disc?
Attachments
Peter,
suspension: maybe you replace the phenolic compound the drive is mounted in with a brass/lead compound. Then you have high mass.
Then suspend this heavy platform by hanging it into a rope or a silicone tubing ring just the way a noisy harddisk drives or a µphone
is suspended in frames. No metal springs!
suspension: maybe you replace the phenolic compound the drive is mounted in with a brass/lead compound. Then you have high mass.
Then suspend this heavy platform by hanging it into a rope or a silicone tubing ring just the way a noisy harddisk drives or a µphone
is suspended in frames. No metal springs!
The reason I used phenolic material was ifor ts better damping characteristics than MDF and most of all, the easiness to machine (so I could do it myself).
Incidentally, I was at one guy's house today with quite a high end setup. He modified his Versa Dynamic TT (air bearing on platter and arm) by removing all suspentions. He placed it on granite box housing PS, which was standing on granite table with two slabs sandwiching 😉 damping material between (blown rubber). He said that it works better than suspension.
I just tried to lift up my playing transport and I noticed that the amount of bass decreases.
Incidentally, I was at one guy's house today with quite a high end setup. He modified his Versa Dynamic TT (air bearing on platter and arm) by removing all suspentions. He placed it on granite box housing PS, which was standing on granite table with two slabs sandwiching 😉 damping material between (blown rubber). He said that it works better than suspension.
I just tried to lift up my playing transport and I noticed that the amount of bass decreases.
Peter,
most soft supensions have way too much damping. I personally am not a friend of such overdamping, i try to use the rigth amount of damping or less, never more.
That your buddy removed suspensions from the Versa and preferred it is indicating to me that the Versa's damping was less than perfectly designed (i am aware this is a sacrilege, saying so).
A soft suspension should work by the principle of supercritical damping. This means, the base resonance is way below any frequency of of interest.
Below the resonant frequency the gain of the transfer function is unity, at the resonance, gain is approchaing infinity (so-called resonance catastrophe, provided the Q is very high or infinity) and above the gain is falling, falling, falling. But as Q never is infinity and damping in the real world is always >0, infinity is not reached. The higher Q/the lower the damping, the higher the resonant peak of the transfer function is. And the steeper the the falling slope above the resonance frequency. And the steeper the slope, the less vibration energy is coupled into the system to be insulated at bottom bandwidth limit, say 20Hz. So: we need a very low resonance frequency and a very high Q to make supercritical damping work efficiently. This also means: big amplitudes. Atleast calculatory amplitudes.
The lower the Q the measlier the insulation.
The reason a low Q for the damping is chosen can be that the designer thinks that too much time goes by until the excited resonance decays.
most soft supensions have way too much damping. I personally am not a friend of such overdamping, i try to use the rigth amount of damping or less, never more.
That your buddy removed suspensions from the Versa and preferred it is indicating to me that the Versa's damping was less than perfectly designed (i am aware this is a sacrilege, saying so).
A soft suspension should work by the principle of supercritical damping. This means, the base resonance is way below any frequency of of interest.
Below the resonant frequency the gain of the transfer function is unity, at the resonance, gain is approchaing infinity (so-called resonance catastrophe, provided the Q is very high or infinity) and above the gain is falling, falling, falling. But as Q never is infinity and damping in the real world is always >0, infinity is not reached. The higher Q/the lower the damping, the higher the resonant peak of the transfer function is. And the steeper the the falling slope above the resonance frequency. And the steeper the slope, the less vibration energy is coupled into the system to be insulated at bottom bandwidth limit, say 20Hz. So: we need a very low resonance frequency and a very high Q to make supercritical damping work efficiently. This also means: big amplitudes. Atleast calculatory amplitudes.
The lower the Q the measlier the insulation.
The reason a low Q for the damping is chosen can be that the designer thinks that too much time goes by until the excited resonance decays.
I was under a big influence (in my reasoning) by the words of Junji Kimura from 47 laboratory:
"The platform/casing of Flatfish is a 2/3 inch thick, machined aluminum board. All the driving mechanisms, pick-up mechanisms and the circuits are directly mounted on this one piece of aluminum board.
The huge difference between the mass of the mechanisms and that of the platform (150g against 1200g) enables to cut off the vibrations caused by the slight off-centering of the disks and the tracing mechanisms returning to the bit-tracing lens itself, allowing us to minimize the amount of servo control dramatically.
This rigid and compact structure of the platform has a very small surface area to receive the vibrations, and its large mass helps to reduce the vibrations smoothly and effectively without any extra damping or suspensions.
As a result, storage of vibration energy was minimized, letting us achieve a refreshingly quick transient response. Compared to the conventional box-type chassis/casings, this platform is almost completely free from any stress of construction. Now, you can hear how much harmony and bottom-end information was obscured under those mechanical stresses
While the mechanism is breaking in, the sound improves too, and less and less discs cause trouble.😉 I think that both methods (suspention and no suspension) can be utilised succesfully. The rest depends on the choice of materials used to support the whole transport assembly. I can virtually tune the sound to whatever effect I want to achieve. My first impression was biased by the setup used for my previous transport, which in many ways is different to CD-Pro. But already, I have to admit that CD-Pro is superior.
"The platform/casing of Flatfish is a 2/3 inch thick, machined aluminum board. All the driving mechanisms, pick-up mechanisms and the circuits are directly mounted on this one piece of aluminum board.
The huge difference between the mass of the mechanisms and that of the platform (150g against 1200g) enables to cut off the vibrations caused by the slight off-centering of the disks and the tracing mechanisms returning to the bit-tracing lens itself, allowing us to minimize the amount of servo control dramatically.
This rigid and compact structure of the platform has a very small surface area to receive the vibrations, and its large mass helps to reduce the vibrations smoothly and effectively without any extra damping or suspensions.
As a result, storage of vibration energy was minimized, letting us achieve a refreshingly quick transient response. Compared to the conventional box-type chassis/casings, this platform is almost completely free from any stress of construction. Now, you can hear how much harmony and bottom-end information was obscured under those mechanical stresses
While the mechanism is breaking in, the sound improves too, and less and less discs cause trouble.😉 I think that both methods (suspention and no suspension) can be utilised succesfully. The rest depends on the choice of materials used to support the whole transport assembly. I can virtually tune the sound to whatever effect I want to achieve. My first impression was biased by the setup used for my previous transport, which in many ways is different to CD-Pro. But already, I have to admit that CD-Pro is superior.
I wonder how many of you CD-PRO users were concern with a proper clamp alignment. At least in my player the clamp was never centered, because the opening was bigger than the top of a TT shaft.
I placed 4 pieces of teflon tape inside the clamp, and now it fits perfectly and is centered every time.😉
I also dealt with the problem of changing discs and getting new TOC each time. I connected a switch to a lid output and instead of using STBY button and clicking twice as well as disconnecting power each time, I click only once and have a new TOC for ea. disc in a more proper way.😉
I placed 4 pieces of teflon tape inside the clamp, and now it fits perfectly and is centered every time.😉
I also dealt with the problem of changing discs and getting new TOC each time. I connected a switch to a lid output and instead of using STBY button and clicking twice as well as disconnecting power each time, I click only once and have a new TOC for ea. disc in a more proper way.😉
Attachments
CD-12 opening mechanism
Has anyone tried to implement a motorized lid function with the CD-12? Looking through the homeoptics site, it appears that this feature has been disabled in their software. In my planned player, I want to implement a hinged, motor driven lid.
Has anyone tried to implement a motorized lid function with the CD-12? Looking through the homeoptics site, it appears that this feature has been disabled in their software. In my planned player, I want to implement a hinged, motor driven lid.
See more of my comments on CD-Pro tuning here: http://www.diyaudio.com/forums/showthread.php?s=&postid=58695#post58695;)
Peter,
I was wondering what make of transformer you used in your supplies and were you sourced them.
Thanks,
Fritz
I was wondering what make of transformer you used in your supplies and were you sourced them.
Thanks,
Fritz
I wanted to use split bobbins transformers, and I found them locally at Active Components. Made by Hammond, 24V AC center tapped, 48VA ea.
Peter,
Have you given any more thought to offering a kit or a full description of your CD-Pro project?
brad
Have you given any more thought to offering a kit or a full description of your CD-Pro project?
brad
OT but still talking about kit
Peter,
Also, did somebody asked if you would do a chassis kit for the amps too? Something that look alike your A75 chassis?
Peter,
Also, did somebody asked if you would do a chassis kit for the amps too? Something that look alike your A75 chassis?
I will see when I finish the current Aleph 5. So far the cost are 200 for chassis (labour and materials) and 400 for sanding and anodizing. This are Canadian funds, not including heatsinks. Talking about monoblocks amp here.
Could you elaborate on the "400 for sanding and anodizing" and we're talking about A75 chassis, right?
We are talking about this amp here http://www.diyaudio.com/forums/showthread.php?s=&threadid=5948&perpage=15&pagenumber=1
The addition of a blue LED improves sonics as I expected. I used two 3mm LEDs powered from display PS. Initially I wanted to mount them through the holes in a top platform, but since they produce spot beam I figured that this approach is better. For plastic frame I used the CD jewel box cover. Looks pretty good this way.😉
Attachments
This was a little bit of plastic around 2 LEDs. The grooves on narrow edge provide nice dispersion.
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