Accutrac 4000 new controller

vovkus

New Member
Hi to all.
About 5 years ago I purchased Accutrac 4000 from local collector. The unit was in a bad shape, but I was able to fix almost all problems except one input of command controller.
Few weeks ago processor run out of his mind and this is time for new project.
On my opinion it is very possible to do reverse engineering and replace old unreliable controllers with something simple.
So, I think to use arduino as a development platform and completely redesign main PCB after I will finish firmware. Remote control system, possible will support universal IR, but it will be next step. I would like to restore full functionality.
This is rather hobby project then practical, but if Accutrack owners interested, I will design direct swap PCB based on new chips.
Will post progress here. Comments are welcome.

This is my quick solution for optical sensors replacement: https://goo.gl/photos/XiHtNifotXeLXrLr8

and this is my Accutrac 4000 after first repair.
 
Excellent idea. This is something I have had in the back of my mind for years. A friend of mine has two of these turntables, both not functioning. I looked into doing this with an arduino awhile ago but ran into a number of potential problems with made me rethink doing it. The logic levels are weird--not ttl or cmos but like -8 v. if I remember and the tonearm control electronics and timings are not well documented, if at all.
But the best of luck if you attempt a fix. Please do keep us informed.
Rick
 
Some project update. I am able to control drive, tonearm servo, clutch. Keyboard driver is done. This is project board on the left and original board on the right.
Yesterday I realize, there are not enough inputs-outputs on Arduino Uno for all signals, which I need to process.
Solution will be split functionality and run master-slave configuration with two boards or use Arduino Mega.
On this point I am very confident to build direct replacement controller board, based on new technology. On this point very simple modification of keyboard PCB is needed (10K resistor need to be shorted).
 
Decision been made. Will run two arduino mini. Almost like original configuration. One controller for keyboard and remote and one for control drive and tonearm.
 
:bowdown:

I had to throw an otherwise perfect 4000 in the trash due the bad controller board, (and no room to store the unit).

They are a great turntable with an excellent sounding cartridge.
 
As I replaced whole controller there is no issue with logic conversion. Possible I have to do some changes on tonearm PCB for optical sensors connections, not sure yet and this is not a big deal.
 
Today I have time just for replace Uno with two Nano boards and connect keyboard to the master controller.
 

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Tonearm PCB will need very simple modification for interfacing with arduino. For head sensor will use simple circuit on LM393. Hope for some progress over coming weekend.
 
All sensors, drive and servo are connected to the arduino and I can process all signals IN and OUT. Head sensors with LM393 work fine, no problems to detect tracks on the LP. Hardware part is done, time for coding :)
 
As a fan and owner I am waiting anxiously for this thread to run it's course. Hoping for great success and new lease on life for some of these fun to play decks. vovkus - thanks for your communication, hard work and expertise.
 
On this point I have to ask how many PCB I need to order. Let me know if you interested. On the end I have plan to do replacement kit, which will include all parts, PCB and instructions. New controller will have special mode to run diagnostics for all Accutrac 4000 devices.
Happy holidays! Cheers.
 
vovkus,
What will be the cost of the pcb?
Did you get the Arduino code completed?
Great project. Congratulations.
Rick
 
Just PCB, no parts cost me $13 each.
Most parts, not include arduinos and headers ordered from Digikey $23
Total cost will be close to $65 (parts and pcb)
Code status:
Complete about 65%. Including control of all devices and sensors and IR remote.
Will continue working on code after put controller together on actual PCB.
 
Outstanding. You have made more progress on fixing these turntables than anyone else ever has.
Please, put me down for one of your circuit boards when the time comes. I already have lots of Arduino stuff (Unos, Pro Minis and Nanos along with proto board shields, headers and such). I have access to a complete non-functioning Accutrac 4000 turntable I would love to get going.
Rick
 
You can marrk me down for one as well. I have 3 of these tables and some units for spare parts. I am a committed 4000 owner.
 
IMG_4070.JPG this is assembled new controller. Sorry for very slow process, but it is just a hobby project, I do it in my free time.
So far just one error on the PCB. Not really important and related only to infrared remote control. Easy fix with one trace cut and one wire jumper. I did not try to run it yet. Possible tomorrow.
 
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