The Secret Society of Lathe Trolls

A few weeks ago, when I happened to be passing a second-hand goods market, a strange device literally jumped out at me. On closer inspection, I saw a kind of tape cassette. But instead of a magnetic pick-up, there was a needle as a pick-up? When I looked even closer, I realised that the tape was not...

And because it's so much fun, here we go again (because it's stereo)! . . C02 FP9_FP-comp-amp 1_3 PCB.jpg . . C03 FP9_FP-comp-amp 1_3 PCB.jpg . . C04 FP9_FP-comp-amp 1_3 PCB.jpg . . Whatever you think, I think it looks great. If it works as it looks, then all is well. Greetings from Austria Thomas

Feedback Amplifier - Part 3 Now that the components have finally arrived, I can start assembling the circuit boards. First the small and flat parts (diodes and resistors). Then the sockets for the ICs and the small capacitors. Then the larger capacitors (tantalum and ElKo's) and finally the transis...

spinnertownblanks wrote: ↑

Thu May 30, 2024 2:34 am

This is absolute gold and somehow you keep making the thread I find most informative and interesting get even better! Endless thanks for all of your work.

Thank you very much! I endeavour to

BRAVO!

I am speechless! First concrete picture. The V-spring and above all the cutting stylus are still missing to determine the actual frequency range when cutting. But a good job for three hours and otherwise nice and small. I'm curious to see what a complete, functioning cutting head looks like on your ...

Feedback Amplifier - Part 2

Based on the circuit diagram, I then made circuit boards that fit my case exactly:
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I hope everything works as planned and I don't disgrace Flo!

Greetings from Austria
Thomas

You wrote: ... As feedback, I used an Ortofon phono cartridge, which gave a signal of about 5 mV at 1 kHz. After mixing the inverted phase FB signal with the inverted RIAA input signal, I had to drive the 200W amplifier to full output power to get close to the 0dB level and 1kHz recording frequency....

here is a photo of the drive coil of a professional head, it is very easy to burn it... :) A drive coil from a professional head will last for many years if handled professionally and is not easy to destroy. If handled incorrectly, any coil will burn out easily. Whether a professional head for $10k...

So many posts with so little content - that's quite remarkable. I won't argue with you, but I have to tell you this. I tested these Chinese vibrators at half speed and reached a fairly even level at 3kHz, which gave about 6kHz at a specific speed of 33.33 rpm. I had to completely change the correct...

Feedback Amplifier - Part 1 I wasn't able to post anything last month. But not because I didn't do anything. On the contrary, I worked so much on my project that there was no time for the presentation. And because I also want to do my contribution properly, I first had to find some time to prepare ...

themagician wrote: ↑

Tue May 28, 2024 9:12 am

...

About to go emboss a mono lateral -12dB to +12dB 315Hz sine wave test, doubt I'll hit 0dB but I can try - wish me luck!
@ronnied_themagician

I wish you luck
Thomas

So many posts with so little content - that's quite remarkable.

And again fantastic work! You also managed to turn the cones - congratulations! And the many small parts - sensational! Thanks for the pictures and the videos - always a pleasure to see your work.
Greetings from Austria
Thomas

Thank you for your quick reply. The FEP insulation can withstand at least 250°C, which is sufficient for the stylus. In your picture with wire winding, the coil is largely without contact. But if they were touching (without insulation) there would probably be a powerful short circuit with temperatur...

Not exactly. OK so the method I use is as follows: 1) cut off a couple of inches of wire (length = 2 x distance of stylus from binding posts, plus 8 x windings, plus a little spare at each end to hold on to) 2) mount the stylus in the head 3) tie one end of the wire to a binding post, leave a littl...

Hey ! Nice vacuum set up! Well built ! For the filter on mine I use makeup little Cotton rags tape under the succion intake and it work well. Looks a bit like your filter. Thank you and glad you like it. My filter consists of the coarse dust filter that usually comes with the dust bags for househol...

Hi Thomas Great project, amazing, thanks for posting the project. Good to read. I am swapping to a channel blower from a vacuum pump. Just got an old one on ebay to try out. Need more power. Best Nik Yes, the disadvantage of the vacuum pump is the lack of air volume (and the pulsating air column). ...

Great! I'm glad you found the error! Well done!

markrob wrote: ↑

Fri Apr 26, 2024 3:10 pm

Hi,
...
... Best to cut with no RIAA and either add it after playback capture or capture with a flat preamp.

3rd Oct Sin 20-20khz.zip

Mark

Cool test signal! I'll have to test that right away! Thank you Mark.