audiojoy said:
Hi, audiojoy
Can you please explain how you did your 90V PSU- the transformer secondary voltage,what kind of filtering (choke or not) you have applied etc.
I have to order the transformer so I just want to check if 63V secondary will be correct for simple filtering PSU type.
Thanks
nemo1968 said:
63V ac will not be enough.... 63Vac will give you around 88V i ideal case....
that means that you will not be able to filter it using inductor or resistors (C-L-C or C-R-C networks).... also you will not be able to use some rgulators too.... the voltage is simply not enough...
if you decide to use inductor filtering it is good to think that you will loose arround 10-20Vdc on the inductor... if you decide to use resistor filtering it is good to count even more voltage drop on the series resistor.... so arround 30 or more will be good.... all that is decided with no tube rectifiers - if you use tube recitifers too than you have to count arround 20-50Vdc voltage drop on the tube rectifier too.... so, definitely your 63Vac is not enough....
if you decide to go with diode recitifier and an inductor filtering i would go on 78-80Vac on the secondary of the transformer....
if you decide to go with the resistor filtering and diode rectifier, than i would go on 90Vac on the secondaryof the transformer..
if you go with the tube rectifier you simply add arround 30Vac on the voltages i calculated above.... so the first one is arround 80+30=110Vac and the second one is 90+30=120Vac.... hopefully this will be helpfull.....
if the voltage (at the end of you filtering line) is not eactly 90Vdc than you will use a resistor from that high voltage line to the ground to drop the voltage a bit more to have the exact value of the voltage you need (90Vdc).....
if you want to use regulator (which i would not suggest) this problem is more complicated...
the best will be to know what you want to do as a psu and than we can do the math...
all in all the point of this post is that 63Vac is not enough for sure....
about mechanism noise
My mechanism is quite noisy, expecially at the start of the disc. It's mounted with a stiff setup (bolts, nuts and washers, all steel), but I don't remenber if it was so noisy at the beginning with green original dampers.
However I tried to put something between the disc and the spindle, and discovered that noise can be eliminated with a foam disc taken from DVD-R spindle (see image below).
The problem is that the foam disc is too thick (about 1.90mm) and the laser can't read the compact disc, so it's a useless solution. I'm searching a less thicker one.
Anyone knows what the laser focus range is?
My mechanism is quite noisy, expecially at the start of the disc. It's mounted with a stiff setup (bolts, nuts and washers, all steel), but I don't remenber if it was so noisy at the beginning with green original dampers.
However I tried to put something between the disc and the spindle, and discovered that noise can be eliminated with a foam disc taken from DVD-R spindle (see image below).
The problem is that the foam disc is too thick (about 1.90mm) and the laser can't read the compact disc, so it's a useless solution. I'm searching a less thicker one.
Anyone knows what the laser focus range is?
Attachments
that foam is not hard in order to maintain the same thickness to have the focus at the same level (during time i assume that the thickness of the foam might change and that will make the focusing problematic again even if You manage to tune it to the foam thickness)... ...
massimo - have you tried to put the foam on the disc - between the disc and the magnet clamp.... maybe this will also be helpfull....
this is the clamp problem also in my opinion...... ...
massimo - have you tried to put the foam on the disc - between the disc and the magnet clamp.... maybe this will also be helpfull....
this is the clamp problem also in my opinion...... ...
I used the Black Hole from Herbie's on my clamp and it made a nice difference. Not that thick. Also tried the grungebuster but seemed to be too much for the circuitry and added errors.
http://herbiesaudiolab.home.att.net/cdmat.htm
http://herbiesaudiolab.home.att.net/cdmat.htm
woodturner-fran said:
Hi Fran,
There is also the possibility of a mounting error.
Twisting the motorboard (proberbly due to overtightning or/and mounting on a surface thats not 'flat' enough) its possible to chance the angle of the 'long shaft' spindlemotors surface to that of the OPU.
Anton.
To massimo:
I have similar construction dimensions as yours. Unlike you, I have 6 mm plate so more room for vertical adjusting.
At first I tought to set CD bottom surface and top plate surface as close as possible. Idea was to get air pillow between in order to get smooth rotation and vibration of disk.
Unfortunately, fluid physics has different behavior. This is fluid mechanic, Reynolds number, and behavior of fluid close to the surface. Certain fluid at certain speed. What we have here is dominant turbulent air flow, not laminar as I expected.
Let me make story short. Distance between rotating CD and plate should be at least 2mm in my case. If there is any hole on top plate, things can go even worse. And we do have hole for laser motion. Bolts heads bring more nonlineariti to surface.
This was tested in my case. At smaller distance noise and erros are expected.
Original Shiga project where made from 15 mm tick Al plate. Whole mass is practically in this plate. With such tickness, some routing from bottom side of plate are neccesseary. That is why I gave up from such fat plate.
Same like you, I had to use 3 bolts for proper levering.
I have similar construction dimensions as yours. Unlike you, I have 6 mm plate so more room for vertical adjusting.
At first I tought to set CD bottom surface and top plate surface as close as possible. Idea was to get air pillow between in order to get smooth rotation and vibration of disk.
Unfortunately, fluid physics has different behavior. This is fluid mechanic, Reynolds number, and behavior of fluid close to the surface. Certain fluid at certain speed. What we have here is dominant turbulent air flow, not laminar as I expected.
Let me make story short. Distance between rotating CD and plate should be at least 2mm in my case. If there is any hole on top plate, things can go even worse. And we do have hole for laser motion. Bolts heads bring more nonlineariti to surface.
This was tested in my case. At smaller distance noise and erros are expected.
Original Shiga project where made from 15 mm tick Al plate. Whole mass is practically in this plate. With such tickness, some routing from bottom side of plate are neccesseary. That is why I gave up from such fat plate.
Same like you, I had to use 3 bolts for proper levering.
To verify the dimensions and design specs of the mechanism.
Follow this link to download the pdf:
http://www.partmate.com/download/OPU/SF-P101N_16P.pdf
Henjo
Follow this link to download the pdf:
http://www.partmate.com/download/OPU/SF-P101N_16P.pdf
Henjo
I'll post some pics later..... but I have to tell you guys what happened. I fitted it all together, transport into the alu box and then bolted all that to a resin/stone baseplate. Total weight I'm guesssing at about 4kg. So I'm listening away and happy enough... not as smooth as my own shiga, but not bad, BGs need to burn in and all that. so then I say for the fun of it lets put a few springs underneath. Well, WOW! what a difference. Increase in resolution, depth and detail instantly. It was really amazing how much difference there was.
So I guess now its time to trick about with some kind of support under it. For anyone else - its worth your while just to get some springs and try them under your otherwise solid transport.
Fran
So I guess now its time to trick about with some kind of support under it. For anyone else - its worth your while just to get some springs and try them under your otherwise solid transport.
Fran
Hi guys benn following this thread from the begining; and a great revelation it was too.
On to my second player now the first one I killed the processor with a slip of the scope probe; but you live and learn! done all the mods on the 2nd now and this little baby sounds great ;thanks Peter and all the other contributors here sound is now flowing.
Hmm now only have to dress her
On to my second player now the first one I killed the processor with a slip of the scope probe; but you live and learn! done all the mods on the 2nd now and this little baby sounds great ;thanks Peter and all the other contributors here sound is now flowing.
Hmm now only have to dress her
