AC main power to high. - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

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
Thread Tools Search this Thread
Old 24th May 2016, 09:27 AM   #1
diyAudio Member
Join Date: Feb 2010
Location: S.California
Default AC main power to high.

I just built a Tubelab SE amplifier, with 300B output tubes. It was designed to work with 3.5K output transformers, at 365 volts B+ voltage, with 120 volts AC main power.
However, my AC main power is up to 124 volts AC in the morning. And I've seen it get as low as 120.5 volts at night. This give me a swing of about plus 15 volts on my B+ voltage.
Maybe I'm being anal, but this really bothers me. Some suggested getting a regulated UPS. Then someone else said that a ups would introduce noise into the system.
I'm looking at the Tripp lite, Smart LCD 1500, regulated UPS. It says it protects against spikes and surges, Cleans up noise, and give a regulated 120 volts AC without using its batteries.
What is your opinion? Should I be worrying about the +/- 15 volts on my B+ voltage? Will a regulated ups help or hurt things?
I wish I could afford a PS Audio Perfect Wave AC power regenerator, but that's not in the cards right now. So what do you all think? Thank you all.
  Reply With Quote
Old 24th May 2016, 10:27 AM   #2
diyAudio Member
JonSnell Electronic's Avatar
Join Date: Dec 2012
Location: The Jurassic Coast, England. GB
A good design will take into consideration changes in power voltages. The heater voltage has a 10% tolerance as will the HT. If it is an issue, redesign it to cope with the changes.
No need for a UPS.
Support for Fender, Marshall and all Valve Equipment including Audio Innovations, Quad and Leak.
  Reply With Quote
Old 24th May 2016, 11:00 AM   #3
AndrewT is offline AndrewT  Scotland
diyAudio Member
Join Date: Jul 2004
Location: Scottish Borders
120.5 to 124 is only +2.9%

your mains probably has a tolerance of 6%
Do you hear any/many others shouting about variations in B+?
regards Andrew T.
Sent from my desktop computer using a keyboard
  Reply With Quote
Old 24th May 2016, 11:21 AM   #4
AllenB is offline AllenB  Australia
diyAudio Member
Join Date: Oct 2008
Originally Posted by Guarnera View Post
What is your opinion? Should I be worrying about the +/- 15 volts on my B+ voltage?
Worrying? Hardly, there are better things to worry about. Tubelab has this sorted.
  Reply With Quote
Old 1st June 2016, 09:01 PM   #5
diyAudio Member
Join Date: Apr 2003
Location: Eastern Pennsylvania
A 'bucking transformer' is another possible solution. See the below linked informative page.

Bucking Xfmrs
  Reply With Quote


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
Availability of 3-phase AC mains supply at High-power Audio Installations inventor Power Supplies 23 1st December 2010 03:49 PM
Power supply:Universal AC input/ Full range,High Efficiency, and High reliability hang Vendor's Bazaar 12 24th July 2009 03:46 AM
Forming main inductor for high-power boost converter Bootstrapper Power Supplies 1 31st October 2008 02:12 AM
help analysing my main AC power milen007 Everything Else 6 27th June 2008 06:15 PM
High Freq. AC Power for Filaments of 300B SE Power Amp? snoopyma Tubes / Valves 6 3rd January 2004 06:21 PM

New To Site? Need Help?

All times are GMT. The time now is 08:22 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright 1999-2017 diyAudio

Content Relevant URLs by vBSEO 3.3.2