Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Instruments and Amps Everything that makes music, Especially including instrument amps.

Conn ST-11 Strobotuner Mod Help
Conn ST-11 Strobotuner Mod Help
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 Search this Thread
Old 24th September 2012, 10:02 PM   #21
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
The clock only needs to be stable on a short term basis. Every time you use the unit, you start by calibrating it to the mains frequency. There is a setting on the front panel just for that. And by the time it is divided down for the motors, a few hertz drift would not be noticed. SO unlike some video source that must sync up to the world, they could get away with a "poorly designed" clock. These little units worked quite well.
  Reply With Quote
Old 24th September 2012, 10:21 PM   #22
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
The units did work well. I still have several of them. Would be nice though if they had a position on the frequency adjust dial that said "locked" or something like that so one could use it for concert pitch only and not have to fuss with calibrating at all.
  Reply With Quote
Old 23rd February 2014, 08:28 AM   #23
Stratwiz is offline Stratwiz
diyAudio Member
 
Join Date: Feb 2014
I have CONN Strobotuner ST-11, and today its motor stopped spinning (lights & pilot LED are on and +50V of motor power transistors is OK, though voltage to the motor is only 1.4 volt). Do you have some troubleshooting documents, or any suggestions?

Thanks,
SW
  Reply With Quote
Old 10th February 2016, 09:03 PM   #24
cos000 is offline cos000  Italy
diyAudio Member
 
Join Date: Mar 2014
Hello to everyone.
I have a ST-11 bought from USA. I live in Italy and I have 230V 50Hz.
I've understood how to mod the tuner for 240V but my problem remain the 50Hz.
Does anyone know how to mod it in order to use calibration with 50Hz (transform it into a ST-12?

Thanks so much
  Reply With Quote
Old 21st March 2016, 12:36 PM   #25
cos000 is offline cos000  Italy
diyAudio Member
 
Join Date: Mar 2014
Quote:
Originally Posted by cos000 View Post
Hello to everyone.
I have a ST-11 bought from USA. I live in Italy and I have 230V 50Hz.
I've understood how to mod the tuner for 240V but my problem remain the 50Hz.
Does anyone know how to mod it in order to use calibration with 50Hz (transform it into a ST-12?

Thanks so much
Hello
No one can help me into find what do I have to change?
  Reply With Quote
Old 21st March 2016, 08:36 PM   #26
Enzo is offline Enzo  United States
diyAudio Member
 
Join Date: Sep 2004
Location: Lansing, Michigan
Do you have a schematic? Mine are miles away. Contact Peterson and ask if they have any such information. Last time I checked (a while ago) Peterson web site has a forum, and a section there where they discuss old Conn tuners. (Peterson bought the Conn assets when Conn went under.)
  Reply With Quote
Old 21st March 2016, 10:57 PM   #27
cos000 is offline cos000  Italy
diyAudio Member
 
Join Date: Mar 2014
Quote:
Originally Posted by Enzo View Post
Do you have a schematic? Mine are miles away. Contact Peterson and ask if they have any such information. Last time I checked (a while ago) Peterson web site has a forum, and a section there where they discuss old Conn tuners. (Peterson bought the Conn assets when Conn went under.)
Hello
Thanks for the reply.
I have schematics of ST-11 which don't include 50Hz mod.
I know about that forum but it seems they have deleted it... I can't find it anymore...
Nevertheless, after one hour spent on calculations and thoughts, I think I solved it also with the help of post #17 of this thread.
I have to write it down and then I'll post my solution.
  Reply With Quote
Old 24th July 2017, 02:07 PM   #28
Souleyman is offline Souleyman  Russian Federation
diyAudio Member
 
Join Date: Jul 2017
Hi there,
I've just got the ST-11 and very interesting about 50Hz mode too.
But I look here and some google results. No answers ((
Does anybody solved this thing with CAL mode?

Looking here on the table of Scooperman

Quote:
Note .... Hz ...... Count ..... tw (ms) ..... Motor Hz ....... Motor RPM
C ....... 261.6 ..... 5D6 ....... 20.39 ........ 49.036 .......... 980.724
C# ..... 277.2 ..... 582 ....... 19.25 ........ 51.957 ......... 1039.15
D ....... 293.7 ..... 533 ....... 18.17 ........ 55.041 ......... 1100.83
D# ..... 311.1 ..... 4E8 ....... 17.14 ........ 58.328 ......... 1166.56
E ....... 329.6 ..... 4A2 ....... 16.19 ........ 61.771 ......... 1235.41
F ....... 349.2 ..... 45F ....... 15.27 ........ 65.469 ......... 1309.38
F# ..... 370 ........ 420 ....... 14.41 ........ 69.375 ......... 1387.50
G ....... 392 ........ 3E5 ....... 13.61 ........ 73.481 ......... 1469.61
G# ..... 415.3 ..... 3AD ....... 12.84 ........ 77.853 ......... 1557.07
A ....... 440 ........ 378 ....... 12.12 ........ 82.500 ......... 1650.00
A# ..... 466.2 ..... 346 ....... 11.44 ........ 87.423 .......... 1748.45
B ....... 493.9 ..... 317 ....... 10.80 ........ 92.617 .......... 1852.34
CAL .... 120 ....... 32E ....... 11.11 ........ 90.000 .......... 1800.00
I've just understood that the CAL mode -- 50Hz or 100Hz or 200Hz or 400Hz possibly must be between G and G# notes but what exactly I don't know.
I've read this mod needed only four diodes moving but did not found what exactly.
Please help to find the solution.
  Reply With Quote

Reply


Conn ST-11 Strobotuner Mod HelpHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

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
Seeking schematic for Conn organ amp Captn Dave Instruments and Amps 12 8th June 2017 02:35 PM
Conn organ conversion to amp nuvo Instruments and Amps 33 7th September 2016 11:01 PM
Conn Caprice organ ThSpeakerDude88 Tubes / Valves 31 12th December 2015 09:27 AM
conn organ amp help jazzgene Instruments and Amps 0 11th April 2006 05:51 PM


New To Site? Need Help?

All times are GMT. The time now is 11:52 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki