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 21st August 2009, 02:16 AM   #1021
Tham is offline Tham  Malaysia
diyAudio Member
 
Join Date: Jun 2006
Hi everyone, not much of listening the last week as I was experimenting with xover points and level matching for my FR/supertweeter speaker system. I had also changed the smoothing caps to 2 x 10,000uF KMGs and letting them to run in.
  Reply With Quote
Old 21st August 2009, 02:31 AM   #1022
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Yes, when I compare regulators this is one of the tests I do. It's almost magical to see that wiggly trace across the screen.

What do you mean by noise output?

I should add, at the end of the day it is still your own subjective impression of the sound that will matter to you. So best will be to listen to all of the alternatives that tickle your imagination, and decide what you like.

Regarding the output impedance of simulated models, I'm not as naive as to think that we'll see any such results in reality. Hopefully someone with good measuring equipment will do a shoot out of all these regulators one day.
  Reply With Quote
Old 21st August 2009, 02:41 AM   #1023
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Quote:
Originally Posted by ikoflexer View Post
What do you mean by noise output?
Iko, I meant the added or generated noise, I guess. Batteries have been shown to produce noise associated with generating current so I guess this would be what I'm wondering about but I'm thinking that it's not going to be too easy, so as you say listening is the final arbiter.
  Reply With Quote
Old 21st August 2009, 02:53 AM   #1024
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Quote:
Originally Posted by jkeny View Post
lab results give 4 mohm
In no way I'm going to argue with professional results.

Quote:
Any idea how to measure noise output?
Using the same fixture as I described above, if you don't apply a sine to the load, i.e. if the load is constant, whatever ripple you see on the output will be noise. But that gets complicated, because on most oscilloscopes the most sensitive setting is 5mV/div. At that setting, I could see no ripple on the scope using salas' v1. I use an old tube scope with 100uV/div sensitivity. But at such noise levels it's hard to say what is picked from the environment and what is dut noise. There are some interesting application notes on this subject (look up app notes by Jim Williams from Linear Technology).

It's good that you're a skeptic, you'll learn a lot this way.

Edit: btw, the only reason why I ever do these tests is to satisfy my own curiousity. I don't claim my tests are worth a penny, and definitely I'm not trying to convince anyone of anything.

Last edited by iko; 21st August 2009 at 02:59 AM.
  Reply With Quote
Old 21st August 2009, 09:26 AM   #1025
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Jkeny:

Will not the batteries add up impedance since you have to chain several of them in series to get up to about 13V for the T amp?
  Reply With Quote
Old 21st August 2009, 09:50 AM   #1026
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Yes, Salas, you're correct - 4 in series (13.2) will add the impedances - 16 to 32 mOhm which could be detrimental? (BTW, these are the batteries of choice being used in the electric vehicles, GM's Volt, etc. - just thought this might be interesting info)

Iko, it's not that I'm sceptical - I believe the great results attested to here - I'm just interested how it will fair against a great battery as it's ultimate test. As Salas said, it would be impressive if it matches or surpasses some of these better (expensive) ones - Soundcheck, I believe, runs all his kit on NorthStar NSB 90 batteries internal R of 2mohm.

As I said, don't mistake my questions as anti-regulators; I'm a user of John Swenson's high voltage series regulators based on Gary Pimm's self biasing CCS and believe it offers excellent sonics.
  Reply With Quote
Old 21st August 2009, 12:26 PM   #1027
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
I am actually much interested in comparisons with everything and subjective results. What is best goes, that is my motto. Ease of making, cost, reliability and functionality included in the mix. A member is using HV Swenson on tubes now that you mentioned, and he is experimenting with my HV simplistic as well, maybe soon he will tell us if there is any subjective gain or not comparing it.
  Reply With Quote
Old 21st August 2009, 01:18 PM   #1028
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
One point favouring your reg is that it scales; the Swenson is only for high voltages & doesn't scale down. A sonic comparison between them would be excellent!
  Reply With Quote
Old 21st August 2009, 01:27 PM   #1029
Salas is online now Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Not directly equivalent to what you gonna make for your T-Amp, its the ring of two, resistor Vref ultra simple HV.

The simplistic LV's scaled from 10V on DC B1 to 250V on Iko's HV high bandwidth version, and from 70mA to 2.5A by now on actual builds.
  Reply With Quote
Old 21st August 2009, 01:57 PM   #1030
jkeny is offline jkeny  Ireland
Banned
 
Join Date: Feb 2007
Location: Dublin
Quote:
A member is using HV Swenson on tubes now that you mentioned, and he is experimenting with my HV simplistic as well, maybe soon he will tell us if there is any subjective gain or not comparing it
Quote:
Not directly equivalent to what you gonna make for your T-Amp, its the ring of two resistor Vref ultra simple HV.
So what he's using wouldn't be a fair comparison then with the SWenson HV?


Quote:
The simplistic LV's scaled from 10V on DC B1 to 250V on Iko's HV high bandwidth version, and from 70mA to 2.5A by now on actual builds.
That's quiet a range, Salas and goes to show that it doesn't rely on a particular device's performance in a limited range for it's operation - something to commend it highly!
  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



New To Site? Need Help?

All times are GMT. The time now is 10:52 AM.


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