same transformer, different voltages? - diyAudio
Go Back   Home > Forums > Live Sound > Instruments and Amps

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

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 25th September 2012, 07:07 PM   #1
diyAudio Member
 
Join Date: May 2012
Default same transformer, different voltages?

Hi,
I had a post on here not so long ago about making a guitar amp. I have a preamp schematic that runs off 15 volts and a power amp chip that works best off about 25V. Can i use the same transformer/power supply? If so how?
Really basic question i know...

Thanks in advance
Callum
  Reply With Quote
Old 25th September 2012, 07:38 PM   #2
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

You tap off and regulate the high current 25V rails down to 15V
for the low current supplies for the preamp, leaving the 25V rails
directly connected to the power amplifier.

rgds, sreten.

Assuming you don't use a multitapped transformer ...
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow

Last edited by sreten; 25th September 2012 at 07:47 PM.
  Reply With Quote
Old 27th September 2012, 06:11 AM   #3
diyAudio Member
 
Join Date: May 2012
OK, thaks for that. Makes sense really when I think about it.
Cheers
Callum
  Reply With Quote
Old 1st October 2012, 06:49 PM   #4
diyAudio Member
 
Join Date: May 2012
I should have asked this before really, but how can i do this? with a voltage divider?
Thanks
Callum
  Reply With Quote
Old 1st October 2012, 07:44 PM   #5
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hi,

Zener diodes or regulators, you can't use a voltage divider for power
supplies. Look up some schematics of amplifiers to see how its done.

rgds, sreten.
Attached Files
File Type: pdf p6.pdf (57.7 KB, 8 views)
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow
  Reply With Quote
Old 2nd October 2012, 04:38 PM   #6
diyAudio Member
 
Join Date: May 2012
Thanks. I have never really done anything with power supplies before, but I thought a divider wouldnt really work.
Cheers
Callum
  Reply With Quote
Old 7th October 2012, 04:49 PM   #7
Minion is offline Minion  Canada
diyAudio Member
 
Join Date: May 2006
Location: Cowican Bay , vancouver island
Depending on yer preamp you might be able to run it off of 25v.
If it is an opamp preamp and runs off a single supply you can most likely run it off of 25v , most opamps can run off of 30v or more and you will get increased headroom useing a higher voltage supply.

Cheers

Maybe post a schematic of your preamp design.
  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
Power transformer HT/B+ voltages vivid Tubes / Valves 20 2nd July 2009 10:32 PM
Rail voltages from 15-0-15 volt transformer Bama Slamma Power Supplies 3 26th November 2006 10:27 AM
the best transformer rail voltages for gainclone? araven Chip Amps 2 30th September 2006 10:31 PM
Calculating secondary transformer voltages ash_dac Power Supplies 14 25th February 2006 04:36 PM


New To Site? Need Help?

All times are GMT. The time now is 09:15 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