Power Transformer size influence on preamp sound. - diyAudio
Go Back   Home > Forums > Amplifiers > Power Supplies

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 3rd January 2013, 10:09 AM   #1
diyAudio Member
 
Join Date: Mar 2007
Default Power Transformer size influence on preamp sound.

Hi anybody have some exsperience with power transformers size influence on sound in a pre or dac ?

If 100 VA is enough will 200 then be better ?
  Reply With Quote
Old 3rd January 2013, 10:11 AM   #2
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
yes, in that the 200va will run cooler....as to how it sounds, maybe......
  Reply With Quote
Old 3rd January 2013, 11:04 AM   #3
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
Originally Posted by Erlend Sæterdal View Post

If 100 VA is enough will 200 then be better ?

Many high end designs are based on this premise. IME though transformer design often trumps raw size as far as sound is concerned. Still, all things being equal bigger is generally better. It may, of course be purely coincidental, i.e. physically larger transformers may also have lower parasitic capacitance between windings.
  Reply With Quote
Old 3rd January 2013, 12:28 PM   #4
diyAudio Member
 
Join Date: Mar 2007
BUT bigger transformer means bigger charging currents for capacitors and worsening sinus curves in supply. Sawtooths instead off sinus ?
  Reply With Quote
Old 3rd January 2013, 01:27 PM   #5
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
That's easily cured with choke/resistor preceding the cap filter. Anecdotally, it appears i am unable to tell the difference between a high and a low power secondary of the same transformer when feeding a dac.
  Reply With Quote
Old 3rd January 2013, 09:50 PM   #6
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Quote:
Originally Posted by analog_sa View Post
Many high end designs are based on this premise. IME though transformer design often trumps raw size as far as sound is concerned. Still, all things being equal bigger is generally better. It may, of course be purely coincidental, i.e. physically larger transformers may also have lower parasitic capacitance between windings.
not sure about lower parasitic capacitance since bigger traffo will have longer or greater coil area....i do however leans towards trying to oversize all my traffo builds...
  Reply With Quote
Old 3rd January 2013, 10:47 PM   #7
diyAudio Member
 
Join Date: Jul 2003
Location: Bath, UK
Surely it only makes a difference if you haven't got the output voltages decently smoothed, let alone regulated.

My preamp uses a 10VA transformer. The only reason it's not still a 6VA unit is because I wanted slightly higher secondary voltages for more Vreg headroom (not available in original trafo core series): but the total draw is still under 5VA.

Temporarily swapping this for something >>20x greater VA rating didn't make a damn of difference on measurement, nor an audible improvement (I'd keep it if so)

Meanwhile the small unit being split-bobbin has useful leakage inductance and secondary resitance and very, very low Cap coupling pri:secondary and as a result - does what I want
  Reply With Quote
Old 4th January 2013, 02:42 AM   #8
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
for some reason, split bobbins seem to run cooler....someday i am going to find out why....
  Reply With Quote
Old 4th January 2013, 03:52 AM   #9
diyAudio Member
 
Join Date: Jan 2013
Been wondering this myself, being new to electroacoustics and all, and seeing how a lot of high end gear has ginormous power transformers, and equally large price tags for said transformers...

I'm looking to power individual console input modules requiring ±17vDC (and hopefully another 48vDC if it'll all fit) and stuffing each into a 1U rack space. I'd like to get the best value without spending more than it's worth, and I can't afford a huge toroidal, and admittedl don't understand why that's preferred to begin with.

what's this VA rating thee speakth of?
  Reply With Quote
Old 4th January 2013, 08:50 AM   #10
diyAudio Member
 
Join Date: Jul 2003
Location: Dona paula, Goa
V is voltage and A is current in Amperes. The transformers are rated as such. For example, if u have a transformer with a 10 volts secondary and its current rating/can output 2 Amps, the transformer is 20 VA.

Gajanan Phadte
  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
Valve power supply - How to size transformer? SanderW Power Supplies 25 4th January 2013 04:12 PM
Influence of power amplifier output coil to frequency response PMA Solid State 22 6th May 2011 07:17 AM
Which parameter of the filtering caps do influence the sound of a gainclone??? Leolabs Chip Amps 34 15th September 2007 04:04 PM
Influence of RIAA impedance value on sound Uchi Deshi Analogue Source 8 19th April 2006 02:08 PM


New To Site? Need Help?

All times are GMT. The time now is 06:49 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