John Curl's Blowtorch preamplifier - Page 1956 - 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
Closed Thread
 
Thread Tools Search this Thread
Old 14th June 2009, 08:05 PM   #19551
brianco is offline brianco  Ireland
diyAudio Member
 
brianco's Avatar
 
Join Date: Aug 2005
Location: Scottish Borders - Kelso; on the famous Tweed River!
It strikes me that many people do not appreciate that people such as John, Joe Pass and many others have absolutely no need to post here. It also strikes me that there are some people who make a point of being rather objectionable to virtually anything an expert has to say. Others raise petty quibbles and some are just downright objectionable!

The first group - those with deep experience and knowledge which they give freely as far as they can (usually relying on the audio industry as the field in which they make their living) - are the givers of this world.

Those who set out simply to attempt to knock down the hard earned knowledge which is given - whilst usually having only a little knowledge garnished with half baked ideas - are not even the takers of this world...they are just knockers-down - with little to contribute.

Others who benefit from the site may well risk loosing the 'givers' because of the social irresponsibility of a very small section of members.
 
Old 14th June 2009, 08:14 PM   #19552
1audio is offline 1audio  United States
diyAudio Member
 
Join Date: Mar 2004
Location: SF Bay Area
Blog Entries: 3
Quote:
Originally posted by scott wurcer


I would love to see if this circuit is more suitable for discrete applications. I have to be careful and not make any lawyers unhappy so in this case I have to stick with simply pointing out what's there already (and in the public domain).
For those of us who have only a tenuous connection to IC design (when I was last close the masks were cut from Rubylith by hand, its changed a lot since then) how good is the transistor matching? I know there are trimming techniques (lasers and fuses) but I understand you have ways of holding devices to pretty close tolerances by design. That would make some tricks possible that are hard for discrete devices. At the same time with discrete parts its possible to get better isolation (thermal and electrical) than possible on a substrate. A little insight into those differences may help us on the outside see whats needed to get those ideas working in discrete parts.
__________________
Demian Martin
Product Design Services
 
Old 14th June 2009, 08:19 PM   #19553
diyAudio Member
 
Wavebourn's Avatar
 
Join Date: Sep 2006
Location: Pleasant Hill, CA
Send a message via Skype™ to Wavebourn
Quote:
Originally posted by brianco
It strikes me that many people do not appreciate that people such as John, Joe Pass and many others have absolutely no need to post here. It also strikes me that there are some people who make a point of being rather objectionable to virtually anything an expert has to say. Others raise petty quibbles and some are just downright objectionable!

The first group - those with deep experience and knowledge which they give freely as far as they can (usually relying on the audio industry as the field in which they make their living) - are the givers of this world.

Those who set out simply to attempt to knock down the hard earned knowledge which is given - whilst usually having only a little knowledge garnished with half baked ideas - are not even the takers of this world...they are just knockers-down - with little to contribute.

Others who benefit from the site may well risk loosing the 'givers' because of the social irresponsibility of a very small section of members.

You forgot about one more group, that tries to position itself above everybody, judging judges, contributing absolutely no technical ideas in any discussion.
__________________
"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
 
Old 14th June 2009, 08:21 PM   #19554
syn08 is offline syn08  Canada
Account disabled at member's request
 
Join Date: Aug 2005
Location: Toronto
Quote:
Originally posted by brianco
The first group - those with deep experience and knowledge which they give freely as far as they can (usually relying on the audio industry as the field in which they make their living) - are the givers of this world.
Yeah, right
 
Old 14th June 2009, 08:28 PM   #19555
KSTR is offline KSTR  Germany
diyAudio Member
 
KSTR's Avatar
 
Join Date: Jul 2007
Location: Central Berlin, Germany
Quote:
Originally posted by brianco
... Joe Pass ...
Now that was a good one! I think that Mr.Nelson""Pass can live well with that mix-up.
Attached Images
File Type: jpg joe-pass-daquisto.jpg (19.3 KB, 565 views)
 
Old 14th June 2009, 08:47 PM   #19556
diyAudio Member
 
scott wurcer's Avatar
 
Join Date: Jan 2004
Location: cambridge ma
Quote:
Originally posted by 1audio

how good is the transistor matching? I know there are trimming techniques (lasers and fuses) but I understand you have ways of holding devices to pretty close tolerances by design.
Demian, far and away the biggest factor is the ability to ratio, exactly, emitter areas on IC's. The uniformity on modern IC's is shocking to those used to discrete design. Six sigma offsets of <100uV are common. Area ratioing is limited by photo lithography which is driven by sub-micron CMOS. Make big bipolars on the same equipment and you get super matching for free. Of course you don't make bipolar masks on the very best, we are approaching (maybe over) $1,000,000 for a 12" mask set.

The multi-tanh circuit needs an exact emitter area ratio, 4 is pretty close, so I figured 5 discretes pulled off of a strip is worth an experiment. I don't know if the second circuit is any better. I have another that I am pretty sure does not use area ratioing and still achieves a flat gm region (no PIM ), but this is unfiled IP that I can not share.
__________________
Silence is so accurate.
 
Old 14th June 2009, 09:05 PM   #19557
brianco is offline brianco  Ireland
diyAudio Member
 
brianco's Avatar
 
Join Date: Aug 2005
Location: Scottish Borders - Kelso; on the famous Tweed River!
Quote:
Originally posted by Wavebourn



You forgot about one more group, that tries to position itself above everybody, judging judges, contributing absolutely no technical ideas in any discussion.

That would include me of course!


Quote:
Originally posted by KSTR
Now that was a good one! I think that Mr.Nelson""Pass can live well with that mix-up.
Now I am really embarrased! Apologies Nelson.


 
Old 14th June 2009, 10:34 PM   #19558
diyAudio Member
 
Join Date: Sep 2006
Quote:
Originally posted by SY
I've removed a bunch of OT posts that dealt with personalities.

Thanks, SY.

You and the other moderators continue to do an excellent job on this thread in particular. We all need a kind reminder when we play a little too rough.

Cheers,
Bob
 
Old 14th June 2009, 11:33 PM   #19559
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
SY,

.........I find it amusing that back in the day,squabbles usually occured among us regular members but today the so called experts/profesionals are more involved in free for all's.................go figure.
 
Old 15th June 2009, 12:29 AM   #19560
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Quote:
Originally posted by KSTR
Now that was a good one! I think that Mr.Nelson""Pass can live well with that mix-up.
It will amuse you to know that my father's name is Joe Pass,
however he is in the aircraft industry.

 

Closed Thread


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 03:11 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