New Doug Self pre-amp design... - Page 2 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 17th March 2012, 01:22 PM   #11
diyAudio Member
 
Join Date: Jan 2007
I was recently reading the "opamp section" of this, thus his design choices come as no surprise. Wish more "designers" would justify their choices as extensively.
__________________
"You have a hierarchy: a mathematician, a physicist (which is a failed mathematician), and an engineer (which is a failed physicist)." - Andrew Jones
  Reply With Quote
Old 17th March 2012, 01:46 PM   #12
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally Posted by dirkwright View Post
There are many chips that have lower noise than the ones he has chosen.

Maybe he expects hobbyists to go ripping into old consoles and sound equipment to get at the NE5532 chips...
Hi,

Voltage noise perhaps, but not current noise and they are not cheap.

Bashing the 5532 is just tedious, what it does, it does exceptionally
well for the price and very few better all round alternatives exist.

It is course currently available and is by far the best value audio
op-amp available, and still will be for the foreseeable future.

The way they are used in this pre-amp, in pairs or quads, (the 4962
is used when a single op-amp is better), gives them low impedance
driving capabilities well beyond any reasonably priced alternative,
with 3dB for the duals and 6dB for the quads noise improvements.

Anyway, those of you that think you know better than D. Self
can of course substitute whatever op-amps you like in his design.

rgds, sreten.

This 2012 design compared to the 1996 design takes the concept
of low impedance levels throughout the pre-amp one step further,
using 1K pots rather than 10K pots with appropriate circuitry.
It will give pretty much state of the art specifications / measurements.
__________________
There is nothing so practical as a really good theory - Ludwig Boltzmann
When your only tool is a hammer, every problem looks like a nail - Abraham Maslow

Last edited by sreten; 17th March 2012 at 01:55 PM.
  Reply With Quote
Old 17th March 2012, 02:10 PM   #13
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by abraxalito View Post
Yes but not at the prices of NE5532 - which was what I was hinting at in speaking of the 'sweet spot'. Unless you can enlighten us?
Well, I didn't know cost was an important consideration. The price of the chips is a small fraction of the total cost of a project. The pretty box is usually far more expensive, as is the power supply.

Your hint wasn't very clear to me at all.

The NE5532 has twice the noise of say a LME49720. When you have so many chips, noise should be a primary consideration in my opinion.
  Reply With Quote
Old 17th March 2012, 02:10 PM   #14
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by sreten View Post
Anyway, those of you that think you know better than D. Self
can of course substitute whatever op-amps you like in his design.
Gratuitous cynicism. People who listen to the design (after all that's the majority DIYer reason for building a preamp, to use it for audio reproduction) may not like the sound and substitute their own choice of opamp based solely on the subjective appeal. Thinking they know better than Mr. Self not required, merely a different end purpose.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 17th March 2012, 02:21 PM   #15
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by brianco View Post
You seem to forget that the end purpose is to play music etc....not to drive test instrumentation.

They are available in bulk or singly virtually everywhere for very low cost.....except, I expect, at audio component 'boutiques' which delight in making far larger profits per $ than do the big players such as digikey etc.
They are a little bit less than half the cost of say the LME49720. The cost of the chips is a minor cost when compared with the entire project.

Of course, when I read that this preamp has tone controls.... well, what ever. Have fun with that. I haven't had tone controls in over 20 years... what for?
  Reply With Quote
Old 17th March 2012, 02:26 PM   #16
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by dirkwright View Post
Well, I didn't know cost was an important consideration.
Cost, in and of itself, is not the consideration. Performance (according to one's chosen metric(s)) per unit cost always is the issue in real-world engineering. This goes right back to Henry Ford, and probably even prior to him : 'An engineer is one who can do for $1 what any fool can do for $2'.

Quote:
The price of the chips is a small fraction of the total cost of a project. The pretty box is usually far more expensive, as is the power supply.
The average Elektor reader can put the design in a shoebox if he/she so desires. Its not going to be an essential part of the design in a hobbyist magazine. The relative cost of the different parts is not really the issue, its a question of optimization of the whole which is engineering.

Quote:
The NE5532 has twice the noise of say a LME49720. When you have so many chips, noise should be a primary consideration in my opinion.
And I'm sure it is a primary consideration in that design - which might be why Mr. Self has chosen two kinds of ICs and uses their strengths accordingly.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 17th March 2012, 02:44 PM   #17
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by abraxalito View Post
Cost, in and of itself, is not the consideration. Performance (according to one's chosen metric(s)) per unit cost always is the issue in real-world engineering. This goes right back to Henry Ford, and probably even prior to him : 'An engineer is one who can do for $1 what any fool can do for $2'.



The average Elektor reader can put the design in a shoebox if he/she so desires. Its not going to be an essential part of the design in a hobbyist magazine. The relative cost of the different parts is not really the issue, its a question of optimization of the whole which is engineering.



And I'm sure it is a primary consideration in that design - which might be why Mr. Self has chosen two kinds of ICs and uses their strengths accordingly.
Oh please. You call this real engineering? in a hobbyist magazine? give me a break. This is a joke.
  Reply With Quote
Old 17th March 2012, 02:46 PM   #18
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Quote:
Originally Posted by dirkwright View Post
You call this real engineering? in a hobbyist magazine? give me a break. This is a joke.
Take your complaints up with Mr. Self then - he is a participant here from time to time. PM him and let us all know how you get on.
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 17th March 2012, 02:52 PM   #19
diyAudio Member
 
dirkwright's Avatar
 
Join Date: May 2011
Location: Virginia
Quote:
Originally Posted by abraxalito View Post
Take your complaints up with Mr. Self then - he is a participant here from time to time. PM him and let us all know how you get on.
Oh brother, what ever. If you want tone controls and a million chips in your preamp, then please, go for it. If you think this is real engineering, please, go right ahead with your belief. I don't care about this little project, I'm not ever going to build it, and I don't care about anyone's justifications for it. You misunderstand. I don't have any complaints because I don't give a hoot about this project. Can you hear me now? I don't care about it!
  Reply With Quote
Old 17th March 2012, 02:54 PM   #20
diyAudio Member
 
abraxalito's Avatar
 
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 101
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
Methinks you do protest overmuch
__________________
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  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
Doug Selfs NE5532 Power Amp. Thoughts anyone ! Mooly Chip Amps 87 15th June 2012 08:08 PM
blameless amp and doug self streetera Solid State 17 16th July 2007 10:06 PM
4th Ed. of Audio Power Amplifier Design Handbook (Doug Self) nickds1 Solid State 4 9th November 2006 12:02 PM
Doug Self Advanced Pre Amplifier PCBs macka Swap Meet 0 9th October 2006 07:41 AM
Help me design pre-amp PS hardcore Tubes / Valves 7 10th November 2004 06:32 AM


New To Site? Need Help?

All times are GMT. The time now is 01:50 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