Search found 1631 matches
- Mon Jan 09, 2023 7:21 pm
- Forum: Classifieds & tip-offs
- Topic: SOLD: Meguro MSG 321 Record Signal Generator
- Replies: 3
- Views: 674
Re: For Sale: Meguro MSG 321 Record Signal Generator
Hi, Any idea on how much he is asking for the generator? Might be out of my league, but I've been interested in the CD-4 format. I have been working on a software decoder for CD-4 and would love something like this to help with the reverse engineering and testing. Do you think it would be possible t...
- Sat Jan 07, 2023 3:47 pm
- Forum: Newbie Forum
- Topic: Gakken Toy Record Maker: Ovservations and Questions
- Replies: 84
- Views: 151581
Re: Gakken Toy Record Maker: Ovservations and Questions
Hi, Yes. I think you have the idea. I'm doing a bunch of hacking to the PO-80. I've updated the motor on mine with a small NEMA 14 stepper and Arduino based controller. Its not quite ready for prime time yet, but keep an eye out in the thread I've been posting to on this subject. I'm also looking to...
- Fri Jan 06, 2023 3:51 pm
- Forum: Newbie Forum
- Topic: Gakken Toy Record Maker: Ovservations and Questions
- Replies: 84
- Views: 151581
Re: Gakken Toy Record Maker: Ovservations and Questions
Hi,
Instead of removing material, you basically empress or indent a groove. Does that make sense?
Mark
Instead of removing material, you basically empress or indent a groove. Does that make sense?
Mark
- Fri Jan 06, 2023 9:51 am
- Forum: Newbie Forum
- Topic: Gakken Toy Record Maker: Ovservations and Questions
- Replies: 84
- Views: 151581
Re: Gakken Toy Record Maker: Ovservations and Questions
Hi, I flip the stylus 180 degrees and emboss on CD-R blanks rather than cut. They stylus lasts quite long and the blanks are cheap. You will have to make a simple adaptor to reduce the center hole of the CD-R to the standard record hole diameter. I 3D print them. Here is an STL file I created that w...
- Thu Jan 05, 2023 11:36 am
- Forum: Circuits, schematics and manuals
- Topic: Brush RC-20
- Replies: 2
- Views: 8413
Re: Brush RC-20
Hi,
Thanks so much for posting this!
Mark
Thanks so much for posting this!
Mark
- Tue Dec 27, 2022 12:10 pm
- Forum: Playback!
- Topic: Screw playback needles set ?
- Replies: 1
- Views: 17311
Re: Screw playback needles set ?
If you value your records, you won't try that. Also note that the RIAA curve you see published is for a typical modern magnetic pickup. If the Astatic is a crystal or ceramic, that curve does not apply. See the article below with some more info. ceramic_cart_1.jpg ceramic_cart_2.jpg ceramic_cart_3.j...
- Thu Dec 22, 2022 9:47 pm
- Forum: Experimenters' & Innovators' forum
- Topic: Holographic recording of analogue-continuous signal.
- Replies: 19
- Views: 4581
Re: Holographic recording of analogue-continuous signal.
Hi, My thinking is that if you want to attract investment money, you need to cobble up the simplest proof of concept prototype be it playback or recording that can demonstrate the merits both technical and economic. Do the least amount of work required using off the shelf parts. Something even as si...
- Thu Dec 22, 2022 9:19 am
- Forum: Experimenters' & Innovators' forum
- Topic: Holographic recording of analogue-continuous signal.
- Replies: 19
- Views: 4581
Re: Holographic recording of analogue-continuous signal.
Hi,
Could this method be reversed to work as an optical pickup?
Mark
Could this method be reversed to work as an optical pickup?
Mark
- Mon Dec 19, 2022 2:16 pm
- Forum: Newbie Forum
- Topic: Rek-O-Kut Model T-45 Question
- Replies: 5
- Views: 1283
Re: Rek-O-Kut Model T-45 Question
Hi,
I think that's right. I would assume if you measure the DC resistance at the terminals that connect to the head, it will be quite high as compared with the 8 and even 500 ohm taps.
I think that's right. I would assume if you measure the DC resistance at the terminals that connect to the head, it will be quite high as compared with the 8 and even 500 ohm taps.
- Mon Dec 19, 2022 12:31 pm
- Forum: Newbie Forum
- Topic: Rek-O-Kut Model T-45 Question
- Replies: 5
- Views: 1283
Re: Rek-O-Kut Model T-45 Question
Hi,
So it is a matching transformer. Do the two black wires go to the cutter head or the power amp output?
Mark
So it is a matching transformer. Do the two black wires go to the cutter head or the power amp output?
Mark
- Mon Dec 19, 2022 10:21 am
- Forum: Experimenters' & Innovators' forum
- Topic: Holographic recording of analogue-continuous signal.
- Replies: 19
- Views: 4581
Re: Holographic recording of analogue-continuous signal.
Hi,
Looks interesting. How would this approach create the groove geometry needed to be compatible with a standard phonograph record? Have you built up a prototype? Are you aware of the HDVinyl endeavor? The were not able to bring it to market despite a great deal of funding.
Mark
Looks interesting. How would this approach create the groove geometry needed to be compatible with a standard phonograph record? Have you built up a prototype? Are you aware of the HDVinyl endeavor? The were not able to bring it to market despite a great deal of funding.
Mark
- Mon Dec 19, 2022 10:15 am
- Forum: Newbie Forum
- Topic: Rek-O-Kut Model T-45 Question
- Replies: 5
- Views: 1283
Re: Rek-O-Kut Model T-45 Question
Hi,
Looks like a matching transformer. I can see what appears to be an 8 ohm tap and a common. Can't see the other terminal markings.
Looks like a matching transformer. I can see what appears to be an 8 ohm tap and a common. Can't see the other terminal markings.
- Wed Dec 07, 2022 2:49 pm
- Forum: Experimenters' & Innovators' forum
- Topic: ATOM / VANROCK CUTTER HEAD RESEARCH
- Replies: 16
- Views: 29023
Re: ATOM / VANROCK CUTTER HEAD RESEARCH
Hi, No need to experiment with the resistor. You are not trying to match impedances here. They added some external resistance to make the amp happy. 1.2 ohms is too low for this amp. This comes at the expense of wasting power in the resistor that could have been applied to the head. It would have be...
- Mon Dec 05, 2022 11:56 am
- Forum: Experimenters' & Innovators' forum
- Topic: ATOM / VANROCK CUTTER HEAD RESEARCH
- Replies: 16
- Views: 29023
Re: ATOM / VANROCK CUTTER HEAD RESEARCH
Hi, That makes sense. That would bring the load impedance up into a better range. The cap bridging the resistor will increase the high frequencies as it will bypass the resistor. The down side is that you are wasting quite a bit of power through the resistor (note the 5W rating). An external high wa...
- Sat Dec 03, 2022 2:42 pm
- Forum: Experimenters' & Innovators' forum
- Topic: ATOM / VANROCK CUTTER HEAD RESEARCH
- Replies: 16
- Views: 29023
Re: ATOM / VANROCK CUTTER HEAD RESEARCH
Hi, I was looking at the datasheet on the STK011 and it seems to be rated at 6.5W into 8 ohms with a 24Vdc supply. I'm not sure if it can drive such a low impedance load. That was why I asked if there was a series resistor added to raise the impedance. The datasheet I found on line is not very good,...
- Fri Dec 02, 2022 8:11 pm
- Forum: Experimenters' & Innovators' forum
- Topic: ATOM / VANROCK CUTTER HEAD RESEARCH
- Replies: 16
- Views: 29023
Re: ATOM / VANROCK CUTTER HEAD RESEARCH
Hi,
That DC Resistance is pretty low. I assume you measured the head out of circuit. Is this correct? I see that a STK011 amplifier is used in some of these machines. Can you determine if the head has any external series resistance added between the amp and the head?
Mark
That DC Resistance is pretty low. I assume you measured the head out of circuit. Is this correct? I see that a STK011 amplifier is used in some of these machines. Can you determine if the head has any external series resistance added between the amp and the head?
Mark
- Sat Nov 26, 2022 10:01 am
- Forum: Newbie Forum
- Topic: (Why) are there no stereo magnetic cutterheads?
- Replies: 2
- Views: 655
Re: (Why) are there no stereo magnetic cutterheads?
Hi, All of the heads you see here are electromagnetic based. You are thinking of a moving magnet design vs a moving coil. Both are still electromagnetic. The places of the coil and magnet are reversed in the two designs. In the moving magnet style, you need a big enough magnet to be able to generate...
- Wed Nov 16, 2022 10:18 am
- Forum: Experimenters' & Innovators' forum
- Topic: Ayima A07 power amp as a cutting amp
- Replies: 1
- Views: 908
Re: Ayima A07 power amp as a cutting amp
Hi, Looks like it uses a TPA3255 which can support the power they are claiming as long as you provide the proper external power supply. These class D amps are quite cheap now and it should work fine if the the design and build quality is sound. I'd give it a shot. Let us know how it works out for yo...
- Mon Nov 14, 2022 7:45 pm
- Forum: Experimenters' & Innovators' forum
- Topic: Hacking The Teenage Engineering PO-80
- Replies: 100
- Views: 601277
Re: Hacking The Teenage Engineering PO-80
Hi, You will need a ton of high frequency boost to get the performance I was getting. Also, you should not use a full IRIAA curve in your signal path as this will kill the lows. Only some slight boost below 50 hz is needed as the head already has the required response from its resonance (about 800Hz...
- Sun Nov 13, 2022 9:13 am
- Forum: Experimenters' & Innovators' forum
- Topic: Hacking The Teenage Engineering PO-80
- Replies: 100
- Views: 601277
Re: Hacking The Teenage Engineering PO-80
Hi, See the attached photo. I first attach the ring to the driver. This acts as an adapter as the driver does not have any mounting holes. After the glue sets, attach this assembly to the frame. There is a gap in the frame to allow the driver terminals to be accessed. The driver ring should be flush...