Wire linear tracking tonearm, TT, phono preamp and germanium amplifier

I needed a quick to assemble TT for my new linear tracking tonearm that is using sapphire guided rollers on a stainless steel wire, so I built one from Marantz tt420 parts like its motor to which I improved the power regulator , activated the internal quartz locked strobe which TC9142 PLL control chip allowed , the Marantz tt used the strobe driven from the mains , added some switches for 45/33 speed, power on and Start/Stop( no Break function so it takes a while to stop by itself, but that is not smth to worry about as the motor coil wires are like 0.1mm ...), added also a 1500$ mirror from a Perkin Elmer spectrophotometer as I couldn't find smth better in time and some better quality wire for the rollers to glide on.
The phono preamp is done with opa1642 and the 2...4watts germanium amplifier using lm6172 and AC180/AC181 transistors is encased in the tonearm aluminium support.I am using it to drive my 250 ohms headphones for the moment.All design is mine, except the Marantz dd motor and its driver, obviously.

At this moment the TT has no suspension springs of any kind, it' s just built out of different materials that impede resonances to a certain degree like plexiglass, leather, polyurethane foam, plastic and plain aluminium, but touching the tonearm is smth I can hear when no music is played.More work will be done anyway.
More photos can be found here and after they approve my latest post the TT parts assembly will be visible:
https://www.tapeheads.net/threads/l...mp-and-germanium-headphones-amplifier.113041/

 

You made a linear tracking tone arm? Wow!

 

Thank you ! It was a natural progression enhanced by a few things that gave me the courage to do it.I' m building diy pivoting tonearms for almost 8 years, for fun only, never had the opportunity to make it a bussiness, but when I had the chance to work on a Beogram 4000 for which I had to repair the broken tonearm, I realized there' s no better way for vinyl than linear tracking.
I bought and restored also a classical motor driven tonearm Scott( Realistic ) linear TT , but then I saw a Clearaudio tonearm and realized there' s no need for electronic tracking.
I' m actually using a more advanced, lower friction bearing system than the most expensive Clearaudio does and while I investigated the air bearing variations I also realized that the connecting wires to the cart will lower that air ideal friction anyway so there' s no clear advantage over a bearing system.
I should have 6 more bearings, I found only 5 around me for a photo, so at least 5 more 3D printed headshell "tonearms" are to come alive.
https://www.diyaudio.com/community/threads/beogram-4000-refurbishment.389112/
https://youtube.com/shorts/JzbXwkHvw1E?feature=shared
Also a very high quality carbon steel knife edge system is waiting ...

 

I love linear trackers so needless to say I think this is awesome. Thank you for sharing your work!

 

I still need to evaluate the resonances, which I didn' t do yet, but for that I needed a silent TT. I have two more refurbished Dual CS 701 for tests, but this was a quicker assembly and I needed some free space around the platter.
The amplifier has a set frequency response of -7db at 20 Hz for the moment as I didn' t wanted to fry my headphones, although It happened once to put full 9V DC on them for like 10 minutes and nothing happened.Next move is to wind back the FR to -3db at 20 Hz, then probably remove the resonances both mechanically and electronically before the power amplifier.The phono preamp is already set to -3dB at 20 Hz which gives -6dB at 20 Hz with amplifier included and that I found absolutely fine with bass reproduction from vinyl over the years.

 

Approaching commercial status...I needed to be able to quickly replace the cart and its holder, so multiple independent wire supports can be adjusted separately for a given cartridge and headshell.A more methodical tensioning system of the wire was devised with the aid of two small screws and those tungsten squares. I wanted also some damping of vibrations and decoupling the wire tonearm from its support with silicon rings looked like the right solution, but then I had to use the tungsten weights to balance it and prevent the cart weight to change the wire distance to the record.This has the potential to cancel some low frequency resonances as well, but that remains to be seen if true or not.
Also went for a very rigid steel pipe support and a bolt to fix its position.Its length was also adjusted for a better position on the turntable foot relative to the platter.
Now I need some serious money for new styluses for the Empire and Shure carts as they are ideal for short light tonearms.

 

The last version seems a lot more resilient to vibrations and also allows me to slip the record under without swinging the tonearm outwards.For the swing action like the Revox does I need a larger diameter bolt and pipe support and tighter tolerances than what I have now to get the same identical position every time I swing it, but that's my next move.
More polyurethane pads under the whole thing and heavier aluminium blocks separated by phone anti- slip silicon gel pads, silicon absorbers under the thick heavy wood plinth supporting everything...
In the mean time I managed to prepare more materials and refurbish on more Technics direct driver from SL-D2 TT.

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I have three more direct drivers to move out of their box : two Dual CS 701 and a PLL controlled Sony.
I intend to add a PLL control to the Duals, but time...
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