Power Supply Resevoir Size - Page 90 - 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 30th August 2012, 05:08 PM   #891
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Quote:
Originally Posted by tsiros View Post
in that case you are not comparing the effect of capacitors on music reproduction, but on music production.
In my opinion it is reproduced by playing the recording through this simple headphone amplifier with different value reservoir caps. This is the core requirement of the thread, what is the minimum reservoir capacitance necessary to produce an acceptable "hi-fi sound".
__________________
Kindest regards
Nico
  Reply With Quote
Old 30th August 2012, 05:38 PM   #892
tsiros is offline tsiros  Greece
diyAudio Member
 
tsiros's Avatar
 
Join Date: Jun 2012
Location: Patra, Greece
Send a message via MSN to tsiros Send a message via Skype™ to tsiros
the music hasn't been recorded. what you are listening is the original instrument sound (and not even that; read below). not a recording of it.

the chain guitar-cable-recording device doesn't produce any sound. it is not a recording of a musical instrument. It is not even the complete musical instrument, not until it reaches a speaker. Until it produces actual sound, it is not complete. It is an electric signal (that of the guitar's pickups) stored in an analog medium. Until it goes into a guitar amplifier and cabinet it is not the sound of the electric guitar.
  Reply With Quote
Old 30th August 2012, 06:28 PM   #893
diyAudio Member
 
danielwritesbac's Avatar
 
Join Date: Nov 2007
Quote:
Originally Posted by Nico Ras View Post
In my opinion it is reproduced by playing the recording through this simple headphone amplifier with different value reservoir caps. This is the core requirement of the thread, what is the minimum reservoir capacitance necessary to produce an acceptable "hi-fi sound".
When I tried that using digital source I got this answer: A particularly suitable regulator. It prevented worsening the harmonic corruption of digital replay. However, if without the regulator's filtering, the varieties possible with same value, different model (different ESR) capacitors were not especially separable from different nearby capacitance values.
__________________
Tools, Models & Software for DIYClipNipper boostLM1875 TurboPowerful TDA7293 kitTDA7294 pt2pt ♦ My post has opinion.
  Reply With Quote
Old 30th August 2012, 07:04 PM   #894
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Quote:
Originally Posted by tsiros View Post
the music hasn't been recorded. what you are listening is the original instrument sound (and not even that; read below). not a recording of it.
What absolute bull!!! Everything that makes music does not necessarily have to plug into an amplifier. I guess an organ does not make a sound unless played in a church.
__________________
Kindest regards
Nico

Last edited by Nico Ras; 30th August 2012 at 07:20 PM.
  Reply With Quote
Old 30th August 2012, 07:23 PM   #895
diyAudio Member
 
Kindhornman's Avatar
 
Join Date: Aug 2012
Location: Los Angeles, California
Nico Ras,
Ha Ha, I guess neither does an acoustic guitar for that reason or a trombone for that matter. Where do you plug them in........ Oh yes, you have to feed the operator......
  Reply With Quote
Old 30th August 2012, 08:10 PM   #896
DF96 is offline DF96  England
diyAudio Member
 
Join Date: May 2007
OK, here is some algebra and comparison with gootee's simulation results. Given the simple assumptions, I would not expect agreement to better than a factor of two in C values.

Assuming a constant current load, the reservoir cap will have a straight line discharge. Assuming the full 10ms is used for the discharge then the voltage drop is 0.01 I/C. You actually get a bit less than this because the discharging cap meets the rising voltage at the start of the next charging period. Assuming that it hasn't discharged too far then an approximation for cosine can be used (cos(x)=1-0.5x^2) and the result is:
Vdrop = 0.01 I/C [ 1 + Xc/(pi Rdc) - sqrt( 2Xc/(pi Rdc) ) ]
where
Rdc = Vpk/I
Xc = 1/( 2pi f C ), f is mains frequency

gootee had a 36Vrms secondary = 50.9Vpk, but nearly 2V could be lost in the rectifier so assume Vpk = 49V.

Now case 1 is 300W peak sq wave into 4R. This is 8.66A peak. We need to add the resistance of the output stage - at least 0.22R emitter resistor plus a bit so say 0.3R. 8.66A on 4.3R is 37.2V. Allow 2V overhead in the output stage (Vbe drops etc.) so we need a minimum rail voltage of 39V. We need say 5% extra current for the driver stage so assume 9.09A. Using the above formula I find that 7300uF will do, giving a Vavg of 44V. Not the same as gootee's results, but not too far off.

Case 2 is 400W peak into 4R. This is 10A peak, so 4.3R needs 43V, plus 2V overhead means 45V rail minimum. Assume 5% driver, so 10.5A current draw. Then I get 23000uF, and Vavg of 47V. Again similar to the simulation. As the minimum voltage is so much closer to the peak (PSU unloaded) voltage we need a much bigger cap.

Note that I assume no audio magic, just a ripple calculation. I assume that the secondary resistance is low enough to be ignored, otherwise the algebra gets more complicated (still working on that!).
  Reply With Quote
Old 30th August 2012, 08:15 PM   #897
tsiros is offline tsiros  Greece
diyAudio Member
 
tsiros's Avatar
 
Join Date: Jun 2012
Location: Patra, Greece
Send a message via MSN to tsiros Send a message via Skype™ to tsiros
Quote:
Originally Posted by Nico Ras View Post
What absolute bull!!! Everything that makes music does not necessarily have to plug into an amplifier. I guess an organ does not make a sound unless played in a church.
Quote:
Originally Posted by Kindhornman View Post
Nico Ras,
Ha Ha, I guess neither does an acoustic guitar for that reason or a trombone for that matter. Where do you plug them in........ Oh yes, you have to feed the operator......

there is a difference between a trombone and an electric guitar.

the former does not have an amplifier and cabinet as parts of the chain to be played

the latter does.

listening to an electric guitar straight from its jack -without into a guitar amplifier and a speaker cabinet- is like listening to an acoustic guitar without a body: you merely hear a metal string vibrating: that is not the guitar.

ya dig?
  Reply With Quote
Old 30th August 2012, 08:37 PM   #898
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
I tend to agree that you have established a possible simple rule of thumb. Thank you DF96 what you show here does correlate with other indications through fairly simple maths.

However, the capacitance increase on inspection seems to follow a power curve for increasing current.
__________________
Kindest regards
Nico
  Reply With Quote
Old 30th August 2012, 09:04 PM   #899
diyAudio Member
 
Nico Ras's Avatar
 
Join Date: Nov 2005
Location: East Coast of South Africa
Quote:
Originally Posted by tsiros View Post
there is a difference between a trombone and an electric guitar.

the former does not have an amplifier and cabinet as parts of the chain to be played

the latter does.

listening to an electric guitar straight from its jack -without into a guitar amplifier and a speaker cabinet- is like listening to an acoustic guitar without a body: you merely hear a metal string vibrating: that is not the guitar.

ya dig?
This still seems to bother you somehow. I never mention that those are electric guitars. You just assumed that everyone who has a guitar is into heavy metal, punk or garage rock. I am into non of those I am sorry. I like acoustic jazz.

My friend I prefer real natural instruments without distortion, fuzz boxes, waa waa and the like.

The fact that I have an active guitar does not make it an electric guitar it makes it an acoustic guitar with a special Shure PG27 fitted. This is a microphone that monitors the micro acoustics of the whole instrument not a typical pick-up bar.

Why bend your brain over this so much, is it important that I must listen to CDs recorded in a special way. Is there any preferred music that you feel I should rater listen to and at what level would be to your liking.

Just lump it guy, if it is that important to you do it your way and draw your own conclusions I am already deep into my experiments drawing notes and making conclusions and I am not going to use any electric guitars even if you insist. I can use my wife's cello to check out at what note the power supply crashes.
__________________
Kindest regards
Nico

Last edited by Nico Ras; 30th August 2012 at 09:33 PM.
  Reply With Quote
Old 30th August 2012, 09:31 PM   #900
tsiros is offline tsiros  Greece
diyAudio Member
 
tsiros's Avatar
 
Join Date: Jun 2012
Location: Patra, Greece
Send a message via MSN to tsiros Send a message via Skype™ to tsiros
Quote:
Originally Posted by Nico Ras View Post
This still seems to bother you somehow. I never mention that those are electric guitars. You just assumed that everyone who has a guitar is into heavy metal, punk or garage rock. I am into non of those I am sorry. I like acoustic jazz.
how do you plan to record them without a mic? You said you will record them without a mic.

I did not assume anything about having a guitar. Jazzists playing with an electric guitar use amplifiers and cabinets, too.

Quote:
Originally Posted by Nico Ras View Post
My friend I prefer real natural instruments without distortion, fuzz boxes, waa waa and the like.
Irrelevant what you prefer. I prefer the violin, but this is irrelevant, too. On that subject, you think the violin doesn't have distortion? It is a very harmonic rich instrument and its waveform is quite close to a slightly overdriven guitar. Oh right, the electric guitar, most important musical instrument of the 20th century, is not a "real natural instrument". Right.

Quote:
Originally Posted by Nico Ras View Post
The fact that I have a microphone on the guitar does not make it an electric guitar it makes it an acoustic guitar with a special microphone fitted.
You're the one who said that you will record your gibson without a mic.

Quote:
Originally Posted by Nico Ras View Post
Why bend your brain over this so much, is it important that I must listen to CDs recorded in a special way. Is there any preferred music that you feel I should rater listen to and at what level would be to your liking.
My brain isn't strained one bit. I don't care what you listen to or how. I said: 1)The perfect recordings for listening with headphones are binaural recordings. If you still have doubts, read up on it. 2) The electric signal coming out of an electric guitar is not the sound of the instrument. It has to go into an amplifier and a speaker cabinet. The amp/cab combination are as part of the instrument "electric guitar" as is the body of hollow-body instruments. You might want to hear the electric guitar's strings move about, but in the 12 years of playing electric guitar and in the 20+ years of listening, i have never once seen someone record the electric guitar by sticking a mic in front of the strings.(edit: or even the electric signal directly). It is always with an amp+cab (or amp/cab simulator/emulator). You're the one who said you will record the guitar without a mic and for the life of me i can not think of a way to record a guitar without a mic, unless it is an electric guitar and you take the output from the jack on the guitar.

Quote:
Originally Posted by Nico Ras View Post
Just lump it guy, if it is that important to you do it your way and draw your own conclusions I am already deep into my experiments drawing notes and making conclusions and I am not going to use any electric guitars even if you insist. I can use my wife's cello to check out at what note the power supply crashes.
no, i do not "lump it", i do not accept orders such that and i do not like your tone at all. I made two claims, and two claims only. I rephrased them above. Tell me which is wrong and how. confront those claims, not me.

Last edited by tsiros; 30th August 2012 at 09:36 PM.
  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
How do you calculate choke size in a power supply? Original Burnedfingers Tubes / Valves 25 5th January 2012 12:23 AM
power supply bypass cap size BigE Power Supplies 11 5th July 2011 02:59 PM
Power Supply Case Size diymixer Power Supplies 1 10th October 2010 05:47 AM
What size power supply should I get for repair work? spooney Car Audio 3 6th December 2007 11:50 PM


New To Site? Need Help?

All times are GMT. The time now is 08:28 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