John Curl's Blowtorch preamplifier part II - Page 3004 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

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 27th November 2012, 03:22 PM   #30031
diyAudio Member
 
Esperado's Avatar
 
Join Date: Jul 2011
Location: France
Quote:
Originally Posted by Joshua_G View Post
The digital gear that sound really good (with good recording and mastering) is rare.
As a sound engineer, bringing my tapes to the mastering room, i can't find too much differences between my recordings and their digital copies, whatever my original tape, analog or digital. Nothing to be upset off.
Vinyl grooving was just a matter to kill my day. All the dynamic and little details gone away, and all those noises, you don't need any blind test, just you cry !!!
In my last studio, with a lot of digital equipment, mixing desks, recorders, effects, computers etc... as long we stayed in the digital domain, never something to worry about. But we had a VERY good master clock.

In my home system, my unique secret is "RE-CLOCK" for no jitter.
But my system does not play nicely bad recordings, it plays the sources as they are.
__________________
Ultimate Protection and more.The Only Source of Knowledge is experience, everything else is just information” ©A. Einstein

Last edited by Esperado; 27th November 2012 at 03:29 PM.
  Reply With Quote
Old 27th November 2012, 03:28 PM   #30032
PMA is offline PMA  Europe
diyAudio Member
 
PMA's Avatar
 
Join Date: Apr 2002
Location: Prague
Quote:
Originally Posted by Esperado View Post
Can someone explain me this sudden interest in this poor poor 4558, that I would not use more than any TL0.72 for audio or even NE5532 ?
I am afraid it will be soon used somewhere (again) as a "cost effective" audio solution
__________________
Pavel Macura
http://web.telecom.cz/macura/audiopage.html
  Reply With Quote
Old 27th November 2012, 03:33 PM   #30033
diyAudio Member
 
Esperado's Avatar
 
Join Date: Jul 2011
Location: France
Quote:
Originally Posted by jneutron View Post
The intent is to eliminate any bouncing of the reference node the amplifier sees. Your technique is certainly viable, but my concern is that safety.The issue would be one of making sure the ground is reliable for life...both equipment's and humans.
You are right. I'm divorced, my sun prefer to listen his headphones, and with so few very good records to buy each year, i don't worry to die :-)

Well, just a question, serious for a while. Any interest to use a loudspeaker's line adapted in impedance , while amp source is near 0 Ohm ?
__________________
Ultimate Protection and more.The Only Source of Knowledge is experience, everything else is just information” ©A. Einstein

Last edited by Esperado; 27th November 2012 at 03:45 PM.
  Reply With Quote
Old 27th November 2012, 03:45 PM   #30034
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by jneutron View Post
The other socks go to mars. That's what the NASA announcement is going to be ..they found a mountain of single socks.
Those who create the information control he world.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers.” -- Plato, 447-367 BCE
  Reply With Quote
Old 27th November 2012, 03:50 PM   #30035
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
Quote:
Originally Posted by PMA View Post
I am afraid it will be soon used somewhere (again) as a "cost effective" audio solution
4558 really is a "strawman" part in audio discussions

even RocketScientist doesn't recommend it - and he's all about "cost effective for audio"

NwAvGuy: Op Amp Measurements
  Reply With Quote
Old 27th November 2012, 03:54 PM   #30036
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally Posted by john curl View Post
Wavebourn, I agree that in mid fi applications, the 4558 is 'adequate' I have been listening through 4558's on an SACD player that I have had for the last 10 years or more. Without DIRECT COMPARISON with better equipment, it is difficult to find any problem. YET, Barrie Gilbert's analysis PREDICTS FM distortion, so we should note it, and perhaps avoid it with our 'best' designs.
John, please see my disclaimer: for higher power gain I would not use them. But for buffers, and stages with gain about 20 dB they are adequate. Of course, I mean biased by 6K8 to the + rail, because as-is they are not acceptable at all for any high end duty.
__________________
"Our youth [...] have bad manners, contempt for authority; they show disrespect for their elders, contradict their parents, [...] and tyrannize their teachers.” -- Plato, 447-367 BCE
  Reply With Quote
Old 27th November 2012, 03:55 PM   #30037
diyAudio Member
 
Join Date: Mar 2002
Quote:
Originally Posted by Esperado View Post
Can someone explain me this sudden interest in this poor poor 4558, that I would not use more than any TL0.72 for audio or even NE5532 ?
Very high slew rates and current feedback make all the difference between a dump system and an other, fast like light, transparent and light like air, on my point of view.
I'm not sure about 072 but 4558 sounds MUCH better than
LF356 (similar to 072).
  Reply With Quote
Old 27th November 2012, 04:04 PM   #30038
diyAudio Member
 
Joshua_G's Avatar
 
Join Date: Nov 2008
Location: Small village, Israel
Quote:
Originally Posted by Esperado View Post
As a sound engineer, bringing my tapes to the mastering room, i can't find too much differences between my recordings and their digital copies, whatever my original tape, analog or digital. Nothing to be upset off.
Most of the people are quite happy with most of the digital gear available today.
Some people, me included, find that most of the digital gear available today sound crappy.

As long as it sounds good to you, all is well. You don't have to spent a lot of money for a really good sounding digital gear.

Quote:
Originally Posted by Esperado View Post
Vinyl grooving was just a matter to kill my day. All the dynamic and little details gone away, and all those noises, you don't need any blind test, just you cry !!!
My experience is different from yours.
Indeed, of all the vinyl records I have, only few are in a good condition. However, those records that are in good condition sound to me better than the best CDP I've ever heard.

To my view, based on my auditory experience, this is the perfect example of the lack of correlation between how audio gear is measured (by conventional measurements, that is, THD and SNR) and how it sounds.

Indeed, on most of the vinyl records I have there is some surface noise, at times also some cracks. Yet, those surface noise and cracks have lesser impact on the sense of realism of the music than most digital gear I've heard.

Possibly, different people pay greater attention to different aspects of the sound. Possibly, some people mind more how quiet it sounds, while others mind more the sense of realism the music have.

In an ideal world, we would have both – quietness and sense of realism. In our present world, I'm still looking for something that will have both (something which I can afford to purchase). However, when it comes to CDs, my suspicion is that, due to the Red Book Protocol limitations, even the best CDP possible will not have the sense of music realism that vinyl records have.

To my experience, Hi-Rez audio can sound as good as vinyl records. So far, I didn't find any Hi-Rez recording which is good enough for me to pay for it. To my view, the poor quality of recent recordings and masterings can be explained by the fact that so many sound engineers and music producers are happy with most of the CDPs available today. When they aren't aware of the sense of music realism, they will not produce recordings that have such a sense of realism. Another reason is that the music industry, including the recording and mastering processes, is aimed for the masses. It seems that the masses aren't looking for a sense of music realism.
  Reply With Quote
Old 27th November 2012, 04:06 PM   #30039
diyAudio Member
 
jneutron's Avatar
 
Join Date: Jan 2004
Location: away
Quote:
Originally Posted by Esperado View Post
You are right. I'm divorced, my sun prefer to listen his headphones, and with so few very good records to buy each year, i don't worry to die :-)

Well, just a question, serious for a while. Any interest to use a loudspeaker's line adapted in impedance , while amp source is near 0 Ohm ?
Using a matched impedance speaker line is the best in terms of getting the information to the load at the same time. The debate is and always has been, does it make a noticeable difference?

All transmission lines have a propagation speed, v = c/sqr(LC), c being lightspeed. It is erroneously assumed that the information makes it to the speaker at that prop speed. That is incorrect. The propagation speed of any cable is the speed at which a signal with the proper current to voltage ratio will propagate. If the cable is 100 ohm, only a signal with a voltage 100 times the current (100 volt, 1 amp) will travel at the cable prop velocity. If the load is 10 ohms, the first transit will not produce 10 amperes at the load. It will take much longer for the load current to reach 10 amperes. What confuses everybody is the fact that audio is so much slower than t line propagation that the leading edge delay is lost in the transition speed.

The current rate of rise at the transducer at the far end will have a frequency and load impedance dependence rate. If there is a huge mismatch between line and load, there will be a slower response to a change in the signal. If the line and load match, the response will be exactly delayed by the prop velocity and line length. If horribly mismatched, the delays can be in the sub 10 microsecond domain, localization territory.

If you use load which matches the line, the amp will NOT see any capacitance, no matter what the cable C is, no matter how long it is.

If the load unloads at hf, the amp will see the capacitance. If the amp is hot where the load goes high z, it can oscillate.


This also occurs with IC's as well.
jn
  Reply With Quote
Old 27th November 2012, 04:25 PM   #30040
jcx is offline jcx  United States
diyAudio Member
 
Join Date: Feb 2003
Location: ..
Quote:
If horribly mismatched, the delays can be in the sub 10 microsecond domain, localization territory.
um, 10 us = ~1/8”, 3mm sound prop distance in air

I don't have my chair, speakers that closely aligned – do you? multiple drivers lots further apart on the cabinet – even the tweeter cone/dome has modes on that scale...

only barely possibly relevant if you have > ~10 us mismatch between R,L channels with speakers and rooms - the sub 10 us numbers come from headphone listening
don't we expect speaker identical models speaker terminal impedance to match even a little? , maybe even better than 10%?
  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 10:37 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