how to remote control a rotary switch based attenuator - Page 2 - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

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 17th February 2008, 10:51 PM   #11
diyAudio Member
 
Join Date: May 2005
Location: Hungary
Jeb-D., I have tried, but I did not found it accurate enough. Even with a constant number of steps after making the contact does not provide near same position. I have tried to make a prototype in the meantime with a disc with small holes for light gate, hand made disc but immediately far better. The 0.5mm hole provide very tight control.

the DC motor does not work if you wnat to handle it by hand also, because of the gears. You need to use the DC motor with gears, but the stepper can connect 1:1, and not really recognizeable when de-energized.

I have two ways now, the control disc or the stepping solenoid. The second one would be perfect (if not too noisy).

Regards,

JG
  Reply With Quote
Old 17th February 2008, 11:23 PM   #12
diyAudio Member
 
Join Date: May 2005
Location: Hungary
I forgot to put the link in :
http://www.nsfcontrols.co.uk/pdf/sol...0LSteppers.pdf
  Reply With Quote
Old 17th February 2008, 11:42 PM   #13
Jeb-D. is offline Jeb-D.  United States
diyAudio Member
 
Jeb-D.'s Avatar
 
Join Date: Nov 2005
Location: SoCal
Never heard of a stepping solenoid. Based on your experience, it sounds like adding a remote to a stepped attenuator is more trouble than it's worth. Good luck! Let us know if you get it working well.
  Reply With Quote
Old 18th February 2008, 04:10 AM   #14
Eva is offline Eva  Spain
diyAudio Member
 
Eva's Avatar
 
Join Date: Oct 2003
Location: Near the sea
Send a message via MSN to Eva
Why going through so much trouble when even the lowest cost volume control IC in the market is probably more linear and quieter than the best tubes and output transformers ever built? I'll never understand.
__________________
I use to feel like the small child in The Emperor's New Clothes tale
  Reply With Quote
Old 18th February 2008, 06:23 AM   #15
gootee is offline gootee  United States
diyAudio Member
 
Join Date: Nov 2006
Location: Indiana
Blog Entries: 1
Quote:
Originally posted by Eva
Why going through so much trouble when even the lowest cost volume control IC in the market is probably more linear and quieter than the best tubes and output transformers ever built? I'll never understand.
Or, it could even be easily and cheaply done, probably with better performance than a switched attenuator (and no moving parts), with LED & photocell combos used as voltage-controlled resistances for an attenuator, with something like a 0v to 5v control voltage to take it from min to max attenuation.

There are commercial 'analog optoisolator' parts that have the LED & photocell encapsulated together, in a light-tight package, such as the Perkin-Elmer Vactrols (e.g. VTL5C2 and VTL5C3) and some of Silonex's stuff (e.g. NSL-32SR2 and NSL-32SR3).

For an example: Diyaudio's GeorgeHiFi uses two of the Silonex NSL-32SR2S parts for each channel, in a series/shunt configuration, in his Lightspeed Attenuator (see the 'Lightspeed...' thread, here at diyaudio.com), which seems to get rave reviews.

It would be trivial to make it voltage-controlled (i.e. with an inverting level-shifting differential amp (one opamp) to give 5v to 0v for a 0v to 5v input, to drive the attenuator's series resistance's current-control with 5 to 0v while the attenuator's shunt resistance's current-control got 0 to 5v).

For a tube amp, you might need to use a different optoisolator part (for a different resistance range than the Lightspeed uses, to get acceptable input impedance for tube amp's output).
__________________
The electrolytic capacitors ARE the signal path: http://www.fullnet.com/~tomg/zoom3a_33kuF.jpg
  Reply With Quote
Old 18th February 2008, 08:50 AM   #16
OzMikeH is offline OzMikeH  Australia
diyAudio Member
 
Join Date: Mar 2007
How about this?

from here:
http://www.diyhifisupply.com/
Attached Images
File Type: jpg remote.jpg (22.4 KB, 735 views)
__________________
Help some guys with funny hair bang two rocks together really hard.
http://athome.web.cern.ch/athome/LHCathome/whatis.html
  Reply With Quote
Old 18th February 2008, 03:47 PM   #17
diyAudio Member
 
Join Date: May 2005
Location: Hungary
Looks good, however, I have tried to put 2 wafers directly on a 5.25" floppy drive head positioner motor and it works fine. the resolution is enough, no gear is needed, for this little bigger motor.
The problem is, I want to handle it by hand also. I do not like the idea of having an encoder at the front panel which drives the wafers by wire.
I try to make a better disc with holes for finding positon. I have an idea how :
I fix the switch on the base of the stand drill with vertical rod. I assemble the disc on the rod of the switch, drill a hole. Turn the swith with one position, than turn a hole again ........ 23 times. This way it should be more accurate.

Regards,

JG
  Reply With Quote
Old 18th February 2008, 03:50 PM   #18
diyAudio Member
 
Join Date: May 2005
Location: Hungary
gootee, I do not thrust LDR-s. After the experiment with the realy network, I decided I do not go again away from the known good way of solving this problem. I just want to add remote control to the rotary switch.

Regards,

JG
  Reply With Quote
Old 18th February 2008, 03:57 PM   #19
diyAudio Member
 
Join Date: May 2005
Location: Hungary
Eva, linearity and noise is not my primary target, but I do not really want to open this tubes vs. solid stage etc. discussion here. Bottom line is, I do non wnat to see them on my audio chain nor most people I know who loves to listen to music.
I do respect them, they are fine for most application.
A year ago I was happy with my black alps, but recently I have tried a stepper with my new amp (2A3 PSE).

Regards,

JG
  Reply With Quote
Old 18th February 2008, 04:20 PM   #20
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
Bentaudio has some kits like that: http://bentaudio.com/parts/dact.html
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New project : R-2R Attenuator With Remote Control V2 bbp Swap Meet 177 12th February 2012 11:42 AM
Dale attenuator remote control zigo3 Parts 7 10th December 2008 04:29 PM
how is the quality of a chip-based volume control VS normal stepped attenuator? jarthel Parts 4 16th July 2007 02:40 PM
Rotary switch Freddie Solid State 1 30th August 2001 07:55 PM


New To Site? Need Help?

All times are GMT. The time now is 02:41 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2