New Embossing Stylus!

[Fela Borbone]

. Did you already tried to make real cutting carbide similar to diamond design?

I tryed, but not for long enough, managed to get a continuous swarf, but way too noisy.
Nothing like a diamond, for that.

[EposLab]

Instead of cones, I grind triangles, to emboss uprigth relative to the record. I expect more detail in the groove, but the elastic limits ot the plastic don't seem to care too much about sharp shapes.

Dear Fela, i was curious about the sound of your triangle stylus so i did on one of my tungstens .
All i can say is that it sound amazing!
I dont think emboss can go any better that this

[grooveguy]

This sounds really exciting, fellows. Epos, your embossing already sounds superb, I'd be interested in hearing a sample of what you can do with the triangle shape at 'real time'; that is, recorded and played at 33-1/3. With the Apollo/Transco people unable to deliver blanks, and with cutting styli at premium prices and pretty much single-sourced, a good embossing system may prove the 'trolls' salvation.' Keep up the good work, share your findings here on the group, and if you are able, make some of these embossing sytli available for sale.

[EposLab]

I'd be interested in hearing a sample of what you can do with the triangle shape at 'real time'; that is, recorded and played at 33-1/3.

I did test the same track at 33rpm and there is a real improvement at high frequencies (even I was half way at the 7" disk!)..
Although I have to work a little on the sound as this voice is a real challenge to record on vinyl due to no much space between the lines!
...but as for now have a look a this beautiful embossing stylus:

[Fela Borbone]

I'm happy it worked for you.

[EposLab]

Yes I'm happy and thank you for "flashing" my mind with this ! Something similar happens with the phono cartridges, when you have to listen with spherical vs a contact line stylus!
Nest step is to experiment with different angles of the triangle..

[grooveguy]

You get some nice snapshots; is it a digital microscope? So, the 'triangle' stylus is kind of like a traditional cutting stylus, but used backward in the head, so that the record material sees the beveled side of the stylus first, and the groove exits the flat side of the face? Can you show a shot of your stylus from the point, or maybe somehow a 3D view? This is intriguing and very good work!

[EposLab]

Yes got this all using my (g600) microscope. Sorry no 3D, i was never in digital design.
One thing i forgot to mention is that is Dead Quiet too! (tried at 90° with groove width from 2mil to 3mil).

[EposLab]

...tonite found some time and made some test cuts (using pink noise) with purpose to compare the Cone vs the Triangle.
Test cuts were made on 33rpm, at the outer diameter of a 12" disk and the outer of a 7" disk.
Also I used a FLAT cut and a Equalized cut.

1) Comparison graph for 7"disk:

PinkNoise_7_Comparison.jpg

2) Comparison graph for 12" disk:

PinkNoise_12_Comparison.jpg

*Please not that Flat cut is actually not really flat (!) as some components of my setup rolling off abit at high frequencies (above 5kHz). I could fix that using the equalizer but didn't as the purpose is to show the differences. Just imagine that the flat cut is alittle better (above 5kHz) in real time than the graph!
Also at the Equalized graph I have cut off a couple of dbs @ 500-630Hz and a gain a couple of dbs @ 12kHz.

[grooveguy]

Quite remarkable; good work, Epos! Sure would love to see closeup of triangle stylus from front, back and side. This is good.

[EposLab]

Sure would love to see closeup of triangle stylus from front, back and side.

Something like this?

WIN_20200414_185632.JPG

WIN_20200414_185725.JPG

[grooveguy]

Yes, good shots. Now, I'm assuming that the disc surface moves left-to-right in your side view? That the material gets pushed down by that 'ramp' and the embossed groove exits at the point. One other question... embossing with a spherical point generates 'horns' on either side of the groove. Sometimes the playback stylus gets confused and rides between the horns of adjacent grooves, meaning that it's playing back from two different time zones. Do you notice anything different with the triangle? The improvement in top-end in your spectrum plots is notable.

[EposLab]

...embossing with a spherical point generates 'horns' on either side of the groove. Sometimes the playback stylus gets confused and rides between the horns of adjacent grooves, meaning that it's playing back from two different time zones. Do you notice anything different with the triangle?

If you mean the small "hills" on each side of the groove, then yes! They are still there and still the same way cause using the Triangle is still embossing and not cutting (by removing the excess material).

[jjwharris]

I take it that is ground with two flats and still .5mm tungsten?

[EposLab]

I take it that is ground with two flats and still .5mm tungsten?

Yes , this is the same 0.5mm Tungsten!

[grooveguy]

Epos, can you confirm that the 'direction of cut' presents the blank disc surface first to the sloped input to the stylus, and the groove exits at the point? Also, I wonder if a third flat, on the 'backside' of the point, might help present an even smaller point of contact with the groove, or what the implication of residual noise level might be as a result. Just thinking of a traditional cutting-stylus used 'backward,' which some have tried with varying success.

[EposLab]

On the pictures i show above , the first pic is the side of the stylus we see when we cut. The second pic is the side view of the stylus.
I was already thinking the same but i believe this way it's even better. If i have to make third flace face on back ,it will look like a real triangle and it will have an angle, it means that the side contact areas will have a angle too which is not really good .Something similar happens using a cone . On this design the side contact areas are very close to vertical (if not 90° vertical) and this way it can have more accurate results especially on high frequencies.
Maybe you're confused with the pictures . The actual part of the stylus which is used while embossing is a very little part on the top of the tip only! Considering a groove of 2mil (5um), only the 1% (5um / 500um) of the tip are is used!

[grooveguy]

Thanks for that Epos; I think I'm having trouble communicating my question. Just want to make sure which direction the stylus is facing when embossing. I'm assuming that it's like the picture here:

Snap8.jpg

...which shows the un-embossed disc entering the angled part of the stylus tip, the opposite from how a cutting stylus works. Just to confirm. Thanks!

[EposLab]

Yes exactly as pictured !

[grooveguy]

Great, thanks. I'd love to try one. You say you use simple cigarette lighter fuel (liquid, not butane!) and pretty much a vertical angle for the stylus. Do you need to wash the record afterward, or does the fluid evaporate? I always considered that stuff pretty volatile, does it last for the whole side?