about ccs of Leach Amp - Page 3 - 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 18th December 2005, 04:48 AM   #21
diyAudio Member
 
acenovelty's Avatar
 
Join Date: Aug 2004
Location: SF Bay Area
Some folks can multi-task in this genre, teach, lecture, write and design amp(s) that pass the test of time.
Do it successfully over a really long time.
Others can't.
I can't.

Here in not so sunny California today (bit of needed rain), my medical treatment will be by a hands on academic clinician. We're truly blessed here.

As a personal aside, over the past fifteen years I have corresponded with dozens of people over the world about these amps.
Folks just quietly go on building it for their own pleasure.
There really was a time before this forum and the internet made it so much easier to share Prof. Leach's design.

I like Leach amps too........
Attached Images
File Type: jpg face3.jpg (92.9 KB, 348 views)
__________________
Two people can keep a secret if one of them is dead.
  Reply With Quote
Old 18th December 2005, 05:18 AM   #22
Account Disabled
 
Join Date: Aug 2004
Location: Earth
Hi Ace,

The internet certainly has certainly eliminated the tyranny of distance and disseminated views. Unfortunately it has a downside. In introducing people with similar views, it encourages navel -gazing one-eyeedness so visible on these fora.

Tony, I was designing original amplifiers commercially in 1974 - my first commercial products. Featuring the, new at the time, MJ15003/4 in CFT's unheard of then - with dethumped CCS Vas and degenerated diff'l front ends. Apart from the designs for others like the TAS golden ear award winning unrevolutionary Magnet 300F and folded cascode preamp in 1994, my Eidetic amplifiers of 1990 were 'giant killers' that , in a loaf of bread size, and a fraction of the price blew away the likes of ML, krell, Classe etc..

and some others later patented my topology despite copyright ( US patent office seems to not look too hard for prior art - to the great satisfaction of their applicants).

My new Simple Killer amp topology is truly revolutionary and a way audiophiles can have all the benefits of modern MOSFET technology and still be responsible to mother earth, our sustainer. Worth a professorship - bah. Probably be expected to hyphenate my name, put on airs, or teach people who really don't want to learn just want a piece of paper.


Cheers,
Greg
  Reply With Quote
Old 18th December 2005, 06:05 AM   #23
diyAudio Member
 
acenovelty's Avatar
 
Join Date: Aug 2004
Location: SF Bay Area
Evenin' Mr.amplifierguru,
"My new Simple Killer amp topology is truly revolutionary and a way audiophiles can have all the benefits of modern MOSFET technology and still be responsible to mother earth, our sustainer."
BTW, just how are sales going? You certainly plug yourself often and blatently enough on this thread.

Downside of the internet? Hmmmm. I'm pretty sure there are some really nasty folks out there using it to figure out how to slaughter other innocent folks over a simple difference in beliefs. Not so sure about your navel -gazing one-eyeedness or just what that might mean. I'm sure you're not criticizing people who wish to share information about amplifiers they like contrary to your beliefs? Surely not!! There's quite enough bad air out there already.

I like Leach too..........
Attached Images
File Type: jpg front_board2.jpg (87.5 KB, 387 views)
__________________
Two people can keep a secret if one of them is dead.
  Reply With Quote
Old 18th December 2005, 06:19 AM   #24
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Greg,

just to remind you, this is diyaudio, and members are here to learn, and enjoy while doing it, not nescessarily please mother earth, but themselves!

here we build amps unlike commercial ones, no budgetary constraints, no time completion deadlines, parts and materials are according to what we want, not what others have decided for us and with a production run of only one unit! diye'rs take pride in their creations, it something that they can call "flesh and blood"

let no one take that fun away!

cheers!
__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  Reply With Quote
Old 18th December 2005, 06:20 AM   #25
Account Disabled
 
Join Date: Aug 2004
Location: Earth
Hi Ace,

I'd love to see some open-mindedness. But it's you that has a closed mind agenda. I try to investigate, improve, share information and you seem to try your damnedest to push a blinker agenda! Why is that? DIYers want to try, improve, learn.. not simply be directed into a 25 yo dated bipolar design as though it's a holy relic.

Cheers,
Greg
  Reply With Quote
Old 18th December 2005, 06:26 AM   #26
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Quote:
not simply be directed into a 25 yo dated bipolar design as though it's a holy relic.
oh my, what does it make of 100years old "tubes" then?
__________________
the best advertisement for a good audio design is the number of diy'ers wanting to build it after all the years....never the say so of so called gurus....
  Reply With Quote
Old 18th December 2005, 06:44 AM   #27
Account Disabled
 
Join Date: Aug 2004
Location: Earth
Hi Tony,

Indeed. And I try my utmost to contribute to that ethos while encouraging forward thinking and technological benefits of modern devices/topologies.

The blinker agenda of not questioning a dated design is anathema to me.


Enjoy your 100 yo tubes - they certainly have a romantic 'sound' and place in audio history!
Cheers,
Greg
  Reply With Quote
Old 18th December 2005, 07:31 AM   #28
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
Hi Tony,
re posts15&16.
the lower reference voltage reduces the LTP CE voltage. It is the cascode transistor that now has the very high CE voltage across it. This high cascode differential and low LTP differential voltage is a common method to allow low voltage, low noise input transistors to be used with higher voltage supply rails.

Back to my question:-
All,

Quote:
You could reduce ...... [the reference voltage]....... to about 4V to 7V. The CB capacitance of the input transistors would rise slightly at this lower voltage.
Q. Is CB capacitance an issue?
Q. Is more benefit gained by reducing the CE voltage across the input transistors?
__________________
regards Andrew T.
  Reply With Quote
Old 18th December 2005, 10:52 AM   #29
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Click the image to open in full size.

What I like to know ( and I think this is more in line with topic )
is:

- If someone find we can improve Leach Amp - Input stage in any way?
- Solution more simple, without loss in performance?
- Solution more advanced with gained performance?

- How would this be practically carried out, in detail?
- What parameters in resulting amplifier performance would be better?
- How big a difference would this be, in figures?

- Would these differences improve the overall sound quality of amplifer?

#######################################

Some discussions lead nowhere.
There is not going to be anything gained from it.
Not regarding increasing of knowledge
and not for finding better practical solution to an issue.

There are constructive discussions and there are meaningless argumentations.
I would like to contribute to us being constructive.
  Reply With Quote
Old 18th December 2005, 01:04 PM   #30
diyAudio Member
 
Join Date: Sep 2002
Location: Sweden
Default Not all zeners are noisy

There is a widespread misunderstanding that zeners are always bad and LEDs are always good. That is a simple rule of thoumb, but it seems not true in all cases. May I remind you of the noise measurements I did:
http://www.diyaudio.com/forums/showt...008#post417008

This study was limited and only applies to the particular brands of components I happened to test, but I suspect it captures a very important characteristic of zener diodes: the noise depends very much on the zener voltage. What I found (please have a look at the attached measurements in the link above) was that zener diodes are very noisy for zener voltages around 6 V, but the noise drops for lower and higher voltages. In fact, I found 12 V zeners to be as good as or even better than LEDs. A string of LEDs will add noise sources, and would result in higher noise than a single 12 V zener diode. LEDs are very good for voltages where you can use a single LED, or maybe 2 or 3 stringed together.


Edit: In the case of the Leach amp, also don't forget that the zeners are bypassed with capacitors to further reduce the noise.

This post is not to advocate using the zener solution instead of a ccs, I just want to point out some misunderstandings regarding zeners and noise.
  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
My Leach Amp Clone (LEACH 150) panson_hk Solid State 32 22nd May 2014 11:25 AM
High Current Leach/leach super amp bowdown Solid State 41 2nd March 2011 02:15 PM
anyone have leach PCB? ilyash Group Buys 2 7th September 2007 10:36 AM
Leach Superamp vs Leach 4.5 Samuel Jayaraj Solid State 4 26th October 2002 09:20 AM
Leach amp vs super Leach amp supernet Solid State 0 21st February 2002 10:16 PM


New To Site? Need Help?

All times are GMT. The time now is 03:56 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