Change in frequency mains - Page 5 - diyAudio
Go Back   Home > Forums > Source & Line > Analog Line Level

Analog Line Level Preamplifiers , Passive Pre-amps, Crossovers, 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 5th January 2005, 09:21 PM   #41
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
Default 60HZ to 50 Hz

I have the 'opposite' problem. I have been
using my AC motor with a 60Hz pulley for
US AC frequency, but would like to run it \
at 50 Hz with a 50 HZ pulley because it
would be quiter. Does anyone have a
schematic or drawing for such a converter?
Thanks,
Michael
  Reply With Quote
Old 5th January 2005, 10:06 PM   #42
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Trust me, you don't want to do that. 60Hz is the frequency to use - even if you have to synthesize it.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 5th January 2005, 10:20 PM   #43
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
This Pabst motor was originally built for 50Hz and
Miichell sold a power supply for it that converted 60Hz
to 50 Hz and the received wisdom was that the motor
is quieter at 50 Hz. The supply sold for $800 which
seems whacky even though it looks nicely designed
with two oscillators and two op-amps. Wish I could
get my hands on a schematic or a cheap damaged
model.
Michael
  Reply With Quote
Old 5th January 2005, 11:48 PM   #44
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
My mains is 50Hz, but I use 60Hz on my turntables because it's quieter.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 6th January 2005, 05:33 AM   #45
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
This throws a wrench into my pursuit of 50Hz for
my Gyro's 24VAC Pabst motor. So what's the
argument for that it runs quieter at 60Hz?
I think the argument for 50Hz is that it runs a
little slower and hence less noise. Wish I
could compare myself.
Michael
  Reply With Quote
Old 6th January 2005, 08:29 AM   #46
Raka is offline Raka  Europe
diyAudio Member
 
Raka's Avatar
 
Join Date: Aug 2002
Location: Close to Oistrakh
Quote:
Originally posted by EC8010
My mains is 50Hz, but I use 60Hz on my turntables because it's quieter.

This is interesting, how did you get the impresion that the 60Hz are better? This is for all your tt? Could you please elaborate a bit on this?

After all this time working on the ps, my conclusions are that the voltage divisor MUST be avoided, and that the correct voltage is critical for low vibration.
__________________
What is beyond the speaker?
  Reply With Quote
Old 6th January 2005, 09:05 AM   #47
EC8010 is offline EC8010  United Kingdom
diyAudio Moderator Emeritus
 
EC8010's Avatar
 
Join Date: Jan 2003
Location: Near London. UK
Agreed, 50Hz reduces the rotational speed of the motor compared to 60Hz, but the mechanical noise of a decent sleeve bearing is minimal.

Electrically, a motor is similar to a perfect transformer in parallel with an inductor. The inductor's reactance is proportional to frequency, so the current it passes is inversely proportional to frequency. If that inductor passes too much current its core will saturate and buzz. We want our applied power to go into rotating the shaft, not saturating the parallel inductor. It's my belief that this is why 60Hz allows a lower noise floor than 50Hz. This idea seems to work for old-fashioned 4 pole motors (Garrard 301) and the more modern 24 pole synchronous motors. Remember that turntable wow is not an additive effect - it doesn't just add 0.55Hz to the audio, it's a modulating/multiplying effect that adds noise sidebands either side of each and every audio frequency.
__________________
The loudspeaker: The only commercial Hi-Fi item where a disproportionate part of the budget isn't spent on the box. And the one where it would make a difference...
  Reply With Quote
Old 6th January 2005, 12:39 PM   #48
Mikelo is offline Mikelo  Antarctica
diyAudio Member
 
Join Date: Feb 2004
Location: Colorado, Oregon
Very helpful explanation! I'm going to try to test this.
  Reply With Quote
Old 21st July 2005, 06:59 AM   #49
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
All the PCB's mentioned earlier in this thread have now gone.
A schematic can be found here
Beware its a bmp.

Onvinyl (Rüdiger), I tried to send you this, but your email was over-quota.

Cheers,
  Reply With Quote
Old 17th January 2006, 04:59 PM   #50
pibb is offline pibb  Canada
diyAudio Member
 
Join Date: Jan 2006
Location: Calgary
Send a message via MSN to pibb
Default Thorens Pulley

Hi: A 50 hz Pulley and power converter would get you going. I have a 50hz pulley that I would be willing to trade for yours if you are interested, let me know. ciao

Pibb
  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
Mains voltage change for Sonic Frontiers SFS80 ? Joschl Tubes / Valves 0 8th January 2009 12:02 PM
Low Frequency Mains Noise ruffrecords Tubes / Valves 6 31st October 2008 07:26 PM
Mains frequency variation Circlotron Everything Else 11 3rd March 2008 10:49 AM
Why is mains frequency so low? Nixie Parts 3 29th November 2006 11:13 AM
Mains frequency stability Prune Parts 10 26th November 2004 05:09 PM


New To Site? Need Help?

All times are GMT. The time now is 12:59 PM.


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