Do SMPS have a home at high end audio? - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

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 28th December 2005, 03:21 AM   #1
Jay is offline Jay  Indonesia
diyAudio Member
 
Join Date: Feb 2003
Location: Jakarta
Question Do SMPS have a home at high end audio?

I have plenty of switching power supply units. It seems that they have noise issues. But my computer is silent and can produce good sound. And so do newer commercial DVD players. So what is the real problem here?

Recently I took out a switching power supply which is also used to power up computer monitor. I guess the voltage and current is suitable for at least providing B+ for a tube preamp. Anybody know if this is possible or not?
  Reply With Quote
Old 28th December 2005, 03:58 AM   #2
diyAudio Member
 
Robski666's Avatar
 
Join Date: Sep 2005
Jay,

SMPS and so called Iron PSU's all get built for a cost which means there either good ok or rubbish, that said I have a pre-amp which runs from an smps and it is very clean. I think it all depends what your preference is and what you can get.

There is no reason a well designed SMPS can't be as good as a conventional PSU. Having said that I wouldn't say that computer smps's are always good examples of state of the art electronics.

But I have heard of people modifying them to supply other voltage/current then what they were designed to.

I think it really becomes a personal taste aspect and what your comfortable wit.

Robert
  Reply With Quote
Old 28th December 2005, 05:18 AM   #3
Jay is offline Jay  Indonesia
diyAudio Member
 
Join Date: Feb 2003
Location: Jakarta
5V is very common with SMPS. I have tried this for DAC. While dynamics is outstanding, I do hear unacceptable noise.

Like most of my SMPS, it was well built. I took them from expensive electronic devices. There are at least 5 panasonic chokes on it (and a 3-layers PCB) but still noisy.
  Reply With Quote
Old 28th December 2005, 07:50 AM   #4
diyAudio Member
 
Geek's Avatar
 
Join Date: Sep 2004
I did some R&D on SMPS for automotive tube audio use and found it as good as a SS bench linear supply.

The only think to remember is careful shielding and proper bypassing. I double-shielded (with gap to avoid a ground-loop), looped the wire a couple of times through an RFI toroid and finally out through feedthrough capacitors.
  Reply With Quote
Old 5th January 2006, 09:56 AM   #5
diyAudio Member
 
Join Date: Jun 2005
Location: Metro Manila
The noise from an SMPS is just too high to be acceptable for audio. Ripple & Noise, conducted and radiated emi, switching noise etc.
  Reply With Quote
Old 5th January 2006, 10:20 AM   #6
diyAudio Member
 
sagarverma's Avatar
 
Join Date: Feb 2005
Location: NEW DELHI
Quote:
Originally posted by rascal101
The noise from an SMPS is just too high to be acceptable for audio. Ripple & Noise, conducted and radiated emi, switching noise etc.

switching noise .do u have 'audiophile' ears?30khz is inaudible to humans!
__________________
Never Underestimate The Bandwidth of A Station Wagon Full Of Magnetic Tapes Hurtling Down The Highway...................Andrew S Tanenbaum
  Reply With Quote
Old 5th January 2006, 10:32 AM   #7
nickds1 is offline nickds1  England
diyAudio Member
 
nickds1's Avatar
 
Join Date: Aug 2005
Quote:
Originally posted by rascal101
The noise from an SMPS is just too high to be acceptable for audio. Ripple & Noise, conducted and radiated emi, switching noise etc.
This is a bit of a sweeping statement, aka generalisation.

SMPSs, like all PSUs, are built to spec. Most digital systems can tolerate a certain amount of noise at 50kHz etc, but not so for audio. So, audio SMPSs are heavily filtered and are run at non-audio frequencies. I have built many many SMPSs, a couple of which I use for valve audio use. These are not hack designs, but are high-end systems.

Basically, for the average person, its far easier to build a quiet non-SMPS that an SMPS system - SMPSs are tricky to get right. However, if you do get it right, they are cheap, small, light, highly efficient and very effective. Noise is barely measurable on a good system.

When I use an SMPS for audio use, I use good filters on both input and output e.g. MuRata BNP002-03 and encase the SMPS in a shielding box (as used for small RF projects - you can also use a box made from soldered pieces of single or double sided PCB - another Ham Radio trick).

Nick
__________________
Nicko
"The whole plan hinged upon the natural curiosity of potatoes" - S. Lem
  Reply With Quote
Old 6th January 2006, 12:45 AM   #8
cerrem is offline cerrem  United States
diyAudio Member
 
Join Date: Jun 2005
Location: San Diego, CA
I design SMPS for a living and yes if you use the standard run of the mill designs used in the last 20 years, you will not get good performance in audio...
I have designed switchers that switch as high as 2 Mhz and and produce little noise...
ALso , the use of quasi-resonant/resonant SMPS circuits are very low with EMI ....
There is a place for SMPS in audio, I would recomend switching above 450kHz and also using a resonant topology...

Chris
  Reply With Quote
Old 18th January 2006, 03:04 PM   #9
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Great City of Turnhout, Belgium
Blog Entries: 7
Hi Chris,

I guess you are familiar with the Vicor units, which I think are quasi-resonant (or zero-current switching). I have used a few (the 150W 2nd generation units) in audio designs with good results, but that may have been luck .

What is your opinion on the Vicors for audio use? They also have a RAM (Ripple Attenuation Module) available to further decrease output noise by some 20dB, but the final price gets steep so I am not sure it would be worthwhile.

Jan Didden
__________________
If you don't change your beliefs, your life will be like this forever. Is that good news? - W S Maugham
Check out Linear Audio!
  Reply With Quote
Old 18th January 2006, 03:18 PM   #10
diyAudio Member
 
serengetiplains's Avatar
 
Join Date: Feb 2004
Location: Canada
Chris, further to Jan's post, can you name a few brands of switchers you think give good performance for audio use? Would much appreciate your opinion. I've been looking on the internet, but cannot seem to latch onto proper figures of merit to guide my search.

Any opinions on Tamura switchers? For instance, this one.
  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
FS: HIGH END Home Audio lot..Opera Louspeakers, Triangle Comete, AA Primo, AA, etc. JiggaD369 Swap Meet 6 22nd August 2008 01:32 AM
Bypassing car amplifier SMPS for use in home 96tahoe Car Audio 8 3rd April 2008 09:50 PM
Jack Hammer subwoofers for High-end home audio? cemmany Multi-Way 16 5th April 2006 11:15 AM
Wiring high Watt sub woofers into home audio systems. Broken_Sight Digital Source 1 7th January 2004 11:28 PM
high volt/high current DIY home PS. deepanger Solid State 24 13th December 2002 12:17 AM


New To Site? Need Help?

All times are GMT. The time now is 02:00 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