John Curl's Blowtorch preamplifier part II - Page 2710 - 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 31st August 2012, 12:18 AM   #27091
diyAudio Member
 
Chris Hornbeck's Avatar
 
Join Date: May 2011
Location: Little Rock
Quote:
Originally Posted by scott wurcer View Post
I don't see the point, these circuits are bandaids when you can make only one good flavor of device. Topologically you can show the same crossover issues with low quiescient bias as if you had a class A/B output and the PSRR is do-do.
Sure nuf. Just another Futterman variant. All Julius' children are playin' his licks.

Thanks,
Chris
  Reply With Quote
Old 31st August 2012, 01:49 PM   #27092
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
In any case, some 'successful' designs have lots of potential problems and are not power supply proof, for example. Then we have to go, all out, to make the supplies as clean, low noise, and fast as possible, so they will not add noise or distortion to the main circuit.
  Reply With Quote
Old 31st August 2012, 07:13 PM   #27093
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Here is an example of a low power supply rejection design with 'idealized' through-path.
Attached Images
File Type: jpg alter.jpg (194.3 KB, 258 views)
  Reply With Quote
Old 31st August 2012, 10:50 PM   #27094
wayne is offline wayne  United States
diyAudio Member
 
Join Date: Jan 2002
Location: Northern California
Quote:
Originally Posted by john curl View Post
In any case, some 'successful' designs have lots of potential problems and are not power supply proof, for example. Then we have to go, all out, to make the supplies as clean, low noise, and fast as possible, so they will not add noise or distortion to the main circuit.
And even with good PSRR you might as well make a nice clean power supply or face some criticism from the market or competitor for not doing your best.
  Reply With Quote
Old 1st September 2012, 11:29 AM   #27095
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Even better than average power supply rejection is not perfect, especially at high frequencies. While, I can understand that someone may criticize another's design in the audio marketplace, I don't find it normal to do so. There are many 'myths' as to how we actually operate in audio design and development.
  Reply With Quote
Old 1st September 2012, 03:07 PM   #27096
diyAudio Member
 
john curl's Avatar
 
Join Date: Jul 2003
Location: berkeley ca
Another quiet time, and I hope to once again convey what the goal of hi end audio design is, at least for my colleagues and me.
I keep repeatedly hearing that I am part of some sort of 'conspiracy' to effect people's hearing decisions through propaganda, 'false' advertising, etc.. However, I see very little or no evidence of this in reality, with myself or the majority of my colleagues. Most of us just work to make a successful audio product, often based on our OWN personal opinions of what is important to make it so.

I have made a guideline for myself that I give to my clients to hopefully follow as best as possible. The general principles in this guideline are based on my past experience with making both successful and sometimes, unsuccessful, products. Since my experience goes back 45 years, I have a lot of examples to choose from.

It may seem trivial for me to say what made one of my first independent assignments fail more than 40 years ago. Yet Sony makes the same 'mistake' in one of their latest models, AND I can hear it. Some people cannot learn from others, and they are destined to make the same mistakes. It is an engineering 'trap'.

Now, it has been MY experience that when I deviate significantly from my 'guideline' especially by letting others do a great deal of the layout and construction in their own way with one of my basic designs, that EVEN sticking my name on the design, will NOT make it successful. So much for NAME RECOGNITION.

What about advertising? Well, without any 'advertising', you better have a lot of friends!
Of course, customers have to know that you exist, but that is not necessarily hard core advertising. Often, word of mouth, between audiophiles is enough to get started. A successful review by a known reviewer can give you all the success that you ever need, IF you want to remain a small concern, 'doing what you like to do'.

Of course, many companies take out full page ads in the latest Stereophile or TAS to get themselves introduced. How many people would know about 'Constellation Audio' if they did NOT advertise a bit? The very high expense of these ads reflects also the size of the company. They are usually not a 3 man shop, for example, but at least a small industrial concern. I take these ads with 'a grain of salt' knowing that the actual sonic qualities cannot be expressed in the ad, itself, and you should too.

The bottom line for me, is to tell you to: 'Trust your ears' NOT advertising, measurements, how pretty the case is on the outside, etc. If you are relatively honest with yourself, you will rarely go wrong with this advice. AND if something cheaper or more convenient comes your way and sounds as good as what you have, go for it.
  Reply With Quote
Old 1st September 2012, 07:53 PM   #27097
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally Posted by john curl View Post
Another quiet time
The calm before the storm?
__________________
"This logos holds always but humans always prove unable to understand it, both before hearing it and when they have first heard it."
  Reply With Quote
Old 1st September 2012, 11:01 PM   #27098
morinix is offline morinix  United States
diyAudio Member
 
Join Date: Jun 2006
What did Sony do wrong?
__________________
Robert
Lounge Audio
  Reply With Quote
Old 2nd September 2012, 12:34 AM   #27099
diyAudio Member
 
Join Date: May 2012
Location: Bryant, Arkansas
Gentlemen, Ladies too,

No disrespect intended to anyone but is there a plan or consensus for how to build this preamp. I am new here and it looks like to get up to speed on this thread I would have to read 54,000 (seriously) posts.

I like what the part one posts said about his design but 54,000 posts later I don't see a plan.

Did anyone build this preamp?
What are your thoughts?
Advice?

Thanks in advance for some input.

Mike
  Reply With Quote
Old 2nd September 2012, 01:00 AM   #27100
diyAudio Member
 
Join Date: May 2012
Location: Bryant, Arkansas
my bad.....48,000 posts
  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 01:09 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