The PM-SC99 (The poorman's SC99, my first homemade head)

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flozki
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Post: # 3218Unread post flozki
Wed Jul 30, 2008 6:18 am

a favorite source of cheap hf speakers....

www.monacor.de

for example
http://www.monacor.de/typo3/index.php?id=75&L=0&act=8&act_sub=25&artid=3574&spr=DE&typ=u

could be good. 46mm magnet diameter....best would be a little smaller....


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d1rk
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ANYONE ELSE HAVE a DIY HEAD

Post: # 3245Unread post d1rk
Sat Aug 02, 2008 9:49 am

Surely someone has more secret experiments share it!!

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emorritt
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Post: # 3246Unread post emorritt
Sat Aug 02, 2008 12:35 pm

flo do you happen to know where diamond stylii are available? I know Souri makes them, but unless you buy his machine you can't use his cutters. :? Does Apollo or Adamant make a diamond point? (Hopefully *with* burnishing facets!?!?)

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flozki
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Post: # 3252Unread post flozki
Sat Aug 02, 2008 10:25 pm

you can get the vinylium diamond stylus at vinylium...orby andybee. i dont know if he sells them worldwide..
f.

andybee
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Post: # 3264Unread post andybee
Mon Aug 04, 2008 5:37 pm

very nice head! looks very good!
I want to hear some sounds :P
:D nice post, too :D

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VRCM
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Post: # 4285Unread post VRCM
Fri Jan 30, 2009 11:27 am

motorino wrote::D

compare one vinylrecorder cutterhead with a sc99 vinylium is like comparing a Trabant with a Porsche

sc99 its a profesional cutterhead :wink:

and i have one Trabant!!
I am just glad someone knows what a Trabant is.
Tim

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emorritt
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Post: # 4286Unread post emorritt
Fri Jan 30, 2009 1:13 pm

Yeah, isn't this what you're talking about?? :lol:

http://flickr.com/photos/14060984@N05/2536103452


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markrob
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Post: # 4300Unread post markrob
Sat Jan 31, 2009 11:22 am

Hi Thomas,

Very cool, nice job! I'm doing similar work, so its good to see other DIY efforts. In case you missed it, here is a link to my web page with some photos of my attempts.

http://home.comcast.net/~markrob1066/site/?/home/

Flo mentioned getting rid of the wooden parts, but I've thingking about trying wood as a construction material. I think it would have more natural damping and thus reduce resonances. If you look in the Photos section of my web page, you will see a scan from a 1988 Issue of Audio Amateur magazine. This details a vertical/lateral stereo head design using balsa wood with a fundemental resonance in the 4.5Khz range. I think there are some errors in the drawings, but you can get the idea. Its easy to use a V/L head in 45/45 mode with simple sum and difference matrixing.

I'm looking to add feedback to my head using an cheap electret condensor mic capsule. I've tried using magnetic windings as most pro heads do (see US patent 2522567), but its hard to eliminate cross coupling between the driver and feedback coils. My thought is that a capacitive pickup will not suffer from this problem.

Regards,

Mark

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cuttercollector
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Post: # 4302Unread post cuttercollector
Sat Jan 31, 2009 6:35 pm

Very cool ideas Mark ! AND making your own styli too !
Keep us posted as to how your experiments are sounding.
What material(s) are you cutting?

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VRCM
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Post: # 4304Unread post VRCM
Sat Jan 31, 2009 10:54 pm

What exactly is going on with the speakers. I can't really tell what you did there. Also is that piece of wood that both speakers are connected to connected to the middle shaft or does it just float? What about making some of the parts out of lead? (relating to resonance?) I don't know much about this topic but I am interested
Tim

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markrob
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Post: # 4311Unread post markrob
Sun Feb 01, 2009 11:31 am

cuttercollector wrote:Very cool ideas Mark ! AND making your own styli too !

Keep us posted as to how your experiments are sounding.
What material(s) are you cutting?
To date I've been using some old lacquer blanks I have a stockplile of. I've also tried cutting onto CDR blanks and Vinyl 12". While I can cut onto these materials, the results have been too noisy. I'm still playing with combinations of heat, sylus material, and cutting angles to see if I can get good results. I don't want to go to a diamond stylus.

As far as sound goes, I was able to get a decent result with my stereo cutter design, but I had to use quite a bit of EQ to do so. I intend to take another pass at this head design soon and see if I can get better results.

I also have some ideas (thanks to some of the posts I read here), about making low cost blanks perhaps with a brush or spray laqcuer.

Mark

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VRCM
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Post: # 4313Unread post VRCM
Sun Feb 01, 2009 4:53 pm

I was saying somewhere on this site about using a solution of ammonia to help soften old laquers. Although it seems to go away if you don't cut soon after the soaking. Last summer when I started fooling around with cutting I would put them out on the hot black top for a few minutes. I have not yet tried the combination of the two.

Also can someone explain how stereo is actually cut into the record? I don't see how it could work with one needle.
Tim

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cuttercollector
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how one groove can be stereo

Post: # 4316Unread post cuttercollector
Mon Feb 02, 2009 1:36 am

I have tried to explain this in other posts before.
Anyone else jump in here if I get too confusing.
The amazing thing they did was to make it mono compatible in the sense that if a stereo cartridge plays a mono disc it comes out in normal mono.
Some early experiments were not compatible.
Mono grooves are made when the stylus vibrates in reaction to sound and cuts a modulation into the material to be cut. The stylus can vibrate either up and down as it did in the first cylinder records and Edison flat records, or back and forth as it did in almost all later mono discs.
The groove has 2 symmetrical walls that are the mirror image of one another. When the groove wiggles the stylus back and forth it re-creates the sound.
To make these carry 2 channels of information (for stereo) they decided to make the 2 groove walls carry the 2 channels, so there is a left and right groove wall. This is where it gets a bit harder to understand how it works with one stylus.
I said before in a mono groove there is no difference between the groove walls - when one side moves left so does the other in a mirror image.
In stereo the groove walls are not identical, so the stylus gets squeezed up and down a bit by following the groove, which because it is no longer the same on both walls, gets wider and narrower as distinct features appear on each wall or channel of audio. One can think of the horizontal movement of the stylus as the common material (mono) between the two channels (that is why it is backwards compatible) and the vertical movement as the difference between the 2 channels. You can actually build a cutter and I suppose a playback cartridge 2 ways. By far the most common is to have 2 elements placed at 45 degree angles to the groove, linked to the stylus.
When it moves back and forth, one coil moves in while the other one moves out. They are electrically wired out of phase with each other so that the resultant electrical output is in phase as the coils move opposite of each other. Now when the stylus moves vertically in response to stereo information the coils do not move exactly opposite one another any more.
In fact, if there is an asymmetrical groove wall where the groove pinches and widens, the stylus only moves up and down, driving the 2 coils in and out together, thus producing an out of phase electrical output (remember they are wired backwards from each other) Real normal stereo audio would typically not have this condition, but you get the idea. That is why it is not a good idea to cut loud low frequency information that is in one channel only or where it is out of phase with the other channel. Too much "stereo" and the stylus will be squeezed right out of the groove!
So, in essence one coil reads or cuts one wall while the other coil does the opposite groove wall, as the stylus moves in complex combinations of vertical and horizontal vectors in response to the asymmetrical groove walls created by stereo information.
The other way that has been tried at least for cutting is to turn the stereo signal "inside out" into a "sum" mono channel (Left + Right) of all the common information between the 2 channels and have it drive a coil that cuts the lateral mono information as though it were a mono record, and a "difference channel" (Left - Right) containing only the information that is NOT the same between the 2 channels and have a coil that moves the stylus only up and down to cut this information. It all works out the same.
Those familiar with M/S microphone techniques and their conversion to stereo will realize that this works along similar principles.

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VRCM
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Post: # 4322Unread post VRCM
Mon Feb 02, 2009 10:05 am

So the key to stereo is actually a slight up an down motion in addition to side to side? A little confusing but I think it will start to sink in. Oh. so that is why the two speakers are at an angle. They pull each other side to side when the information is the same and then up and down a bit when it is not. I think I will take time to really understand stereo before I make my own head.
Tim

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cuttercollector
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Post: # 4340Unread post cuttercollector
Tue Feb 03, 2009 2:38 pm

Sort of.
If you imagine a "Y" with the the drive elelment coils whether it is a pickup or cutter, at the top of the Y at 90 degrees to each other and 45 degrees to the stylus or record surface, a sort of flexible pivot that allows both horizontal and vertical movement where the 3 legs of the Y come together, and then the stylus itself at the bottom leg of the Y, you can visualize how it works. If the stylus moves back and forth, the coils are driven in opposition to each other, one moves in as the other moves out.
They are wired so this gives an in phase electical output when you hook up the wires to the proper treminals as indicated. Then, if there is pure up and down movement the coils move in and out together. If one groove wall were unmodulated (no audio signal), theoretically at least, only one coil would move on the side opposite the modulation. The theory is the same for cutting or playback and whether you are bending a piezo element or moving a coil or magnet to generate an electrical signal or driving them with an audio signal to move the cutting stylus.

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VRCM
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Post: # 4344Unread post VRCM
Tue Feb 03, 2009 6:32 pm

Cool. Thank you for the explaination. That was something I was always confused about.
Tim

Aussie0zborn
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Post: # 4375Unread post Aussie0zborn
Fri Feb 06, 2009 10:43 am

MEGAMIKE wrote:iam still confused....
i have cut with presto and neumann and souri head sounds better..
mybe i was not experanced before but all sounds the same.....
and why kingston dont cut polycarbonate.... :)
Ummm... are you serious??? 8) Where on the west coast are you? A guy in Perth bought a Scully lathe from a friend of mine in Sydney about 3 or 4 years ago - is that you by any chance?

And where did you cut with a Neumann head? The only Neumann lathe on the west coast of Australia was owned by Martin Clarke's Clarion Records and he sold it to Festival Records, Sydney in the late 70s / maybe early 80s. There have been no other Neumann lathes in that part of the world since then so I'm just curious where you got all this cutting eperience.

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MEGAMIKE
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Post: # 4386Unread post MEGAMIKE
Sat Feb 07, 2009 2:53 am

... the 8n and 6n used by martin in the 60s 70s is at fremantle museum fremantle perth western aust( but he had atleast 4 lathes in all of his projects/label)and rob muier owns them given to him from his father?..rob may have taken it down for some record fair expo thing..
the neumann heads x2 is still owned by rob muier and yes i lied and did not use the neuamann but witnessed its sound quality.
...the presto 8n we have is from tasmania ...
no scully here.. but a guy bought 1 year ago (what was advertised in the auction as EMI record lathe with blanks)..... but it was sold before we got there...
......

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MEGAMIKE
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Post: # 4387Unread post MEGAMIKE
Sat Feb 07, 2009 3:29 am

...yes no neumann in perth...
:oops: ...

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