Next Yamaha PX3 linear TT on Audiokarma - restoration (problems with photo elements solved)

[RDW]

I started work but they are everywhere...

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Whoa, you let them out of the bag and you’re infested now! Seriously though I have very much enjoyed following your thread.

 

[Fishead]

When that happens, you have no choice but to eat every one you can get your hands on! Achtung!!!

 

[Martynka]

Seriously though I have very much enjoyed following your thread.

Thank you !!!

you have no choice but to eat every one

Yummy Yum... and work done.

I changed belts

If you looked very, very closely with good light and a bit of magnification, one could see the very tiny beginnings of cracking in the old belts

my looks better,

Old one:



and new one:



I checked one more time gummy drive wheel. I don't have crack and stamps.



Last time I cleaned all wheel and shafts with solvent, brush and soap. Now I put with thin needle new oil on all shaft.

PX-3 mission - complete !!!


but... Yamaha has Mogami Neglex 2496 interconnect




It's good cable but enought good for this TT ??

I have three options:

- leave as is
- change cable with better one
- change cable with high level RCA socket ( without drill in PC-3 body )

What do you think ??

 

[Martynka]

and I forgot about it:

Before changed belts when I tilted PX3 my tonearm goes from left to right side.

Now I can tilt near 90 degree and tonearm is still on place !!!

 

[Igor_SPb]

... will try to find proper new LED.

Thank you for your hard work and very detailed report. With the help of guys like you, I was able to restore my turntable. I myself am very weak in electronics. With your permission, I will post photos, as I did. I cut and polished the LEDs, bent the legs close to the base, carefully opened the sensor housings and placed the new converted LEDs there. Externally and functionally, it looks like an original part. I understand that at first glance I did a lot of unnecessary work, but I love beautiful work and this is my hobby.

 

[Martynka]

it looks like an original part

Yes, work level - PRO !!!

It's nice to hear that my work impressed you to repair PX.

I finished my PX-3 completely.

Do you remember :

Yamaha has Mogami Neglex 2496 interconnect

It's good cable but enought good for this TT ??

My friends said that it is one of higher Mogami and it is not necessary to change it but I bought new one. Because I have all interconects Tellurium Q Ultra Black II and speaker cable TQ too I decided to get the same for Yamaha.

I bought Tellurium Q Ultra Black II Phono RCA





removed old Mogami and clean soldering points from old tin



reoved one side of RCA and soldering it with silver/gold/tin



and now I have new interconnect for TT.



Did it change anything... YES !!! Change everything. If you check my posts you can find that I build tube analog outputs for DAC and CD, I build completly DAC with tube too. It is my source number one becouse of dynamics, analytic sounds and for big, wide and high, 3D sound stage. Now on TQ UB II I first time have the same holographic sound stage like from DAC's. Sound is not only the same 3D but much dynamic !!!

I think that oryginal Mogami connectors are Yamaha PX-3 bottleneck.,

 

[Fishead]

Continue to be very impressed with your work, Marcin! Wish Poland weren't so dang far away as I'd just love to hear what you are hearing now with the new interconnects.....happy listening, amigo!

 

[bkatbamna]

This is one of the most impressive refurbishing I've ever seen anywhere. I had an old Pioneer PL-L800 that I really loved but had to sell on ebay as non-working for parts because I have no sense of electronics. To say that the work on the Yamaha is impressive is like calling Niagra Falls a regular waterfall.

 

[Igor_SPb]

I changed belts

Martynka, can you tell the sizes of the old and new belts?
Thank you!

 

[Martynka]

Martynka, can you tell the sizes of the old and new belts?

I try to find old parts from Yamaha, cut it and measure.

 

[Igor_SPb]

Do you know how big should be drop to change H to L ?

I added another 240 ohms to the 680 ohm R37 resistor. With new LED and 920 ohm low voltage of sensor is 0.906 volts and auto mode works great. With original 680 ohm low voltage 0.885 volts. My plan is to increase the 680 ohms step by step until the circuit stops working again and then measure this critical low voltage. But for this I need to buy resistors first. It interesting to me because I want to increase the life of the sensors by reducing the LED current.

 

[pfcs49]

this post gets you real close on belt length: #9
IME even ugly primary (small) belts worked OK
The secondary/large flat belt is often troublesome and NLA....anywhere AFAIK.

 

[Igor_SPb]

this post gets you real close on belt length: #9

Thank you!
The size of the square of three old dried brittle belts of my turntable is 1.4x1.4mm. and length 88mm. (half-length 44). I assumed that they might be not the original ones, or they might have shrunk a lot in size.

 

[Fishead]

Hello @Igor_SPb, if you would just like to get the right belts I was able to order the three small belts from here:

Professor Bizzt's store @ Webstore.com

You might try that if it suits you....they were not very expensive as I recall.

 

[BilboBaggins]

I added another 240 ohms to the 680 ohm R37 resistor. With new LED and 920 ohm low voltage of sensor is 0.906 volts and auto mode works great. With original 680 ohm low voltage 0.885 volts. My plan is to increase the 680 ohms step by step until the circuit stops working again and then measure this critical low voltage. But for this I need to buy resistors first. It interesting to me because I want to increase the life of the sensors by reducing the LED current.

I'm curious, because I would expect you to be able to increase the life of the LEDs by reducing the current through them, but I wouldn't expect that to help the sensors.

 

[Igor_SPb]

I wouldn't expect that to help the sensors.

Thank you for your comment.
I already installed the new LEDs and also tested the circuit with an additional 240 ohm resistor (680 R37+additional 240=920 ohms) and the circuit works fine. With the additional resistor, the current through the LEDs decreased by 27%, and the low voltage of sensor with only original resistor was best by 2.5%. I don't know if these numbers would suggest that without increasing the resistor, the light from the new LEDs is redundant, but I think it could be.
However, electronics is not my forte.

 

[Igor_SPb]

Do you know how big should be drop to change H to L ?? to 6V or low ??

OK.
I did a low voltage test by dimming new red 3mm LEDs by adding resistance.



R37 680 Ohm - low voltage 0.885V
920 Ohm - 0.906V
1160 - 0.942
1400 - 1.35
1640 - 3.4
1760 -4.5 - still working.
1880 - 5.4V - now auto mode not working.

 

[Martynka]

R37 680 Ohm - low voltage 0.885V

I have the same with new LED's.

 

[flavio81]

Guten Morgen Herr @Fishead
, and I do "Polish polish"
(...)
and do handjob

LOL

Great pictures, thank you very much for sharing your work. I also repair turntables.

The cover looks excellent, which Polish polish are you using to polish in Poland? No, seriously, is the "headlight polish" 3M brand? It looks like new...

Greetings from Lima, Peru

 

[Martynka]

No, seriously, is the "headlight polish" 3M brand? It looks like new...

It's something like this:

https://www.amazon.com/SONAX-Headli...2a-b5e8-0b8af2ae2131&pd_rd_i=B01B16LCA8&psc=1