'Best' power regulator for DAC - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 14th October 2011, 06:35 PM   #1
diyAudio Member
 
Join Date: Oct 2009
Location: Brunei
Default 'Best' power regulator for DAC

All,
I am in the process on building a TDA1541a dac, and on this quest I am wondering about your experiences with different regulators to power a dac.

Currently I am using 4 Salas shunt regs for all the supplies which are:
-Analog TDA1541 (-15V)
-Analog TDA1541 (-5V)
-Digital TDA1541 (+5V)
-Digital reclock circuit (+5V)

As far as I could find, the Salas shunts have good performance, both on noise, and impedance up to 200KHz. To me, they also sound nice.

-For the analog lines, this should be fine. There may be better-sounding alternatives though (are there?)

-For the digital lines, I am concerned that the rapidly increasing impedance beyond 200KHz will be problematic, as the clock signals are 2.8MHz and 11MHz.

What are your experiences?
  Reply With Quote
Old 14th October 2011, 07:46 PM   #2
pidesd is offline pidesd  Canada
diyAudio Member
 
pidesd's Avatar
 
Join Date: Apr 2008
Location: montreal (cotes des neiges yo!)
i ve tested a few solutions and so far i found salas 1.1 preceded by heavy filtering with inductances and different sort of cap for each stage ''the best''. heavy bias helps with impedance. of course battry operation is better than mains if you can cope with the cost and complexity. one thing i d like to try is cap multipliers before salas regs. heavy bias helps with impedance.

also, recently i experimented with a copper wire wound in an non inductant pattern which acted as Rset (in salas reg) and found significant improvement. makes me wonder what Rref from non inductive wire would do....
  Reply With Quote
Old 14th October 2011, 07:50 PM   #3
pidesd is offline pidesd  Canada
diyAudio Member
 
pidesd's Avatar
 
Join Date: Apr 2008
Location: montreal (cotes des neiges yo!)
also wonder how this reg would perform in the first post...

Building the ultimate NOS DAC using TDA1541A
  Reply With Quote
Old 14th October 2011, 08:59 PM   #4
diyAudio Member
 
Join Date: Apr 2003
Location: Eastern Pennsylvania
Active current-source fed shunt regulators ( such as the Salas) are my favorite, but require individual setting of each current-source.

In addition to the shunt versus series regulator question you raise there is the feedback versus non-feedback topology question. Regulators are D.C. amplifiers and as such have many of the same concerns of any linear amplifier regarding the affects of feedback upon sound quality. Feedback regulators feature far lower output impedance than non-feedback regulators, and also feature a more exact and stable D.C. voltage setting. However, that lower output impedance usually quickly rises with frequency (due to insufficient gain-bandwidth product of most IC regulators, and many discrete ones too), eventually becoming pretty much ineffective for digital clocks and other high frequency signals, and that more exact and stable D.C. voltage setting usually doesn't matter for audio amplifier circuits. It's usually a regulators A.C. performance that really matters for linear audio applications.

The regulator's output stabilization capacitor, or the powered circuit's bypass capacitor, is what provides quiet power for circuits drawing high frequency current from the regulator, such as typically encountered from digital circuits. The output impedance of that capacitor is equal to their reactance = 1 / (2 * pi * f * C). So, for example, a small 100nF supply bypass/decoupling capacitor on a 10MHz oscillator looks like a regulated voltage source having a 0.160 ohm output impedance (ignoring device package parasitic inductance) to the 10MHz dynamic load of the oscillator.
__________________
Ken

Last edited by Ken Newton; 14th October 2011 at 09:28 PM.
  Reply With Quote
Old 15th October 2011, 08:12 AM   #5
UV101 is offline UV101  England
diyAudio Member
 
UV101's Avatar
 
Join Date: Dec 2008
Location: Oxford
SPowers...........no competition!

I'll be selling my built Salas shunts on here because I've gone back to internal Dac running SPowers again ;-)

Btw, the system I used to work this all out was my ears!!!
__________________
When Bitstream came out, I thought, “my God, what are we going to do...?” Ken Ishiwata http://www.hifisounds.co.uk
JA-88D Class A, Audio Aero Capitole MKII, Focal and Kimber "Leave Nothing as Standard"
  Reply With Quote
Old 15th October 2011, 10:20 AM   #6
Account disabled at member's request
 
Join Date: Aug 2007
discrete voltage regulators from different manufactures, are they all equal?

Replacement Regulators for 7805, 7815 & 7915?

http://www.amb.org/audio/sigma22/

Last edited by KlipschKid; 15th October 2011 at 10:23 AM.
  Reply With Quote
Old 15th October 2011, 04:25 PM   #7
diyAudio Member
 
Join Date: Oct 2009
Location: Brunei
Quote:
Originally Posted by pidesd View Post
i ve tested a few solutions and so far i found salas 1.1 preceded by heavy filtering with inductances and different sort of cap for each stage ''the best''. heavy bias helps with impedance. of course battry operation is better than mains if you can cope with the cost and complexity. one thing i d like to try is cap multipliers before salas regs. heavy bias helps with impedance.

also, recently i experimented with a copper wire wound in an non inductant pattern which acted as Rset (in salas reg) and found significant improvement. makes me wonder what Rref from non inductive wire would do....
Check out the output impedance of the Salas 1.1.... This doesnt look good for digital...

salas 1.1 output impedance.jpg
  Reply With Quote
Old 15th October 2011, 05:18 PM   #8
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
it will be very difficult to find a regulator to work into the very high frequencies of modern digital, but it really doesn't need to be, at these frequencies ANY regulator will be relying on the quality of the localised decoupling caps at the load to do the heavy lifting
  Reply With Quote
Old 15th October 2011, 05:25 PM   #9
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
btw i had the same concerns exactly, check the builds and fairytales thread for conversation on this topic, even incredibly high speed regulator controllers that use high speed gets designed to supply modern PC CPU clock loads will rely on quality ceramic decoupling directly at the load pins. i prefer lifepo4 for clock loads anyway
  Reply With Quote
Old 15th October 2011, 07:46 PM   #10
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Power supply 101 - decoupling close to the pins of digital circuits!
Only that will provide the necessay DC "storage" with low impedance in HF. No reg will be able to do that, no matter how it is build.
Same goes for audio signals - just the capacitors need to be higher.
  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
PSU for DAC using UWB regulator sennator Digital Source 0 27th June 2008 05:51 PM
Super Regulator for DAC rockytro Digital Source 11 19th May 2006 07:31 PM
Does the PCM2902 DAC benefit from an external regulator? aaronl Digital Source 1 21st January 2005 06:32 AM
LDO regulator for CS8412/TDA1543 dac, opinions? setmenu Digital Source 5 5th March 2004 08:02 AM


New To Site? Need Help?

All times are GMT. The time now is 06:51 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