Go Back   Home > Forums > >

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

Rabco SL8E Photoelectric Servo Control Retrofit
Rabco SL8E Photoelectric Servo Control Retrofit
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 5th December 2020, 07:29 AM   #31
Rajkumar_ is offline Rajkumar_  India
diyAudio Member
 
Join Date: Jan 2010
Location: India
Hello after photoelectric servo modification on my Rabco SL8E with led (same nero52) I have notice led turn on & off very few seconds, it’s correct.? Or led continuously turned on? Thanks Rajkumar
__________________
DIY Horn, Rethm Saadhana V2, Gaanam Amp, Dared 845 KR Tubes, Dared 300B, Dared DL2000, CEC TL1 CD Transport, Meridian G08, Bryston BDP-1, DAC Antelope Zadiac Gold, Cable Kimber Monocle XL, AQ SKY, Norduct. Analog: Kenwood L-07D, R2R Pioneer RT-909
  Reply With Quote
Old 5th December 2020, 09:21 PM   #32
diyrayk is offline diyrayk  United States
diyAudio Member
 
diyrayk's Avatar
 
Join Date: Aug 2012
Location: Traverse City, MI
The LED circuit itself is probably working correctly. The ideal is for the motor to operate continuously, and speed up or slow down as the groove pitch varies. You can verify this most easily by monitoring motor voltage directly with an analog voltmeter. With a theoretically constant groove pitch, the motor voltage will also be constant. Groove pitch in the real world is not constant and records are also off-center to some extent, so motor voltage isn't constant but varies up and down with each revolution. LED's like to be either on or off. My guess is that the LED circuit is biased somewhere in the middle of the motor's actual operating voltage range and is turning on and off as the motor swings within that zone. The LED turn-on point could be manipulated by selecting the gain of the added transistor and the value of the added 4K7 resistor.

I deliberately did not include an LED indicator on my arm partly out of laziness but more out of the philosophy that, if I can't hear the effects of the servo in action, I don't want any visual cues that it's operating. I leave my test equipment connected for as long as I need to see what the servo is doing while setting it up but once that's done I prefer to fly/listen 'blindfolded'.

Ray K
__________________
If more is better, then too much is just right.
  Reply With Quote
Old 8th December 2020, 02:09 AM   #33
Rajkumar_ is offline Rajkumar_  India
diyAudio Member
 
Join Date: Jan 2010
Location: India
Rayk absolutely you correct, I have check many LP's many of then off center this is the reason led light (motor) turn on/off, one of the my LP I found correct center than led turn on continuously. Now I have cleared my doubt. I have installed 2 led red & green. Green for carriage and red for lifting. Everything working perfectly. I have post some pictures. Tks lot Rajkumar.
Attached Images
File Type: jpg IMG_20201203_085011.jpg (180.9 KB, 28 views)
File Type: jpg IMG_20201203_112515.jpg (210.6 KB, 29 views)
File Type: jpg IMG_20201208_071157.jpg (251.9 KB, 28 views)
__________________
DIY Horn, Rethm Saadhana V2, Gaanam Amp, Dared 845 KR Tubes, Dared 300B, Dared DL2000, CEC TL1 CD Transport, Meridian G08, Bryston BDP-1, DAC Antelope Zadiac Gold, Cable Kimber Monocle XL, AQ SKY, Norduct. Analog: Kenwood L-07D, R2R Pioneer RT-909
  Reply to this post

Reply


Rabco SL8E Photoelectric Servo Control RetrofitHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Infinity Irs servo control rvito Multi-Way 0 11th May 2017 03:16 PM
Simple Servo Control KatieandDad Everything Else 0 2nd January 2014 02:19 PM
DIY Servo Sub- need help with control circuit flyingtele Subwoofers 1 28th January 2013 08:57 PM
Does anybody know how to use the MCU to control the CD servo? zhangzq71 Digital Source 0 19th December 2008 04:52 AM
Photoelectric valves? bigwill Tubes / Valves 7 11th May 2005 04:27 PM


New To Site? Need Help?

All times are GMT. The time now is 08:49 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki