Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

FAOW
FAOW
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 19th July 2018, 09:40 AM   #91
Attila I is offline Attila I  Germany
diyAudio Member
 
Attila I's Avatar
 
Join Date: Aug 2009
Location: Germany
sorry for being insensitive

A.
  Reply With Quote
Old 19th July 2018, 10:09 AM   #92
juma is offline juma  Germany
diyAudio Member
 
juma's Avatar
 
Join Date: Nov 2005
Location: Berlin
Quote:
Originally Posted by Vix View Post
..simple 1w amp witj Lu1014 j-fet,...

Here you are:
Q1 amplifies voltage and current (common Source mode) and Q2 is a CCS.
R5/R4 ratio sets the gain and R4 sets the Zin - don't use much higher value (up to 10k max) or you'll lose good treble. Of course, you signal/music source should be able to drive that Zin.
R6 keeps coupling cap C1 tied to GND when there is no speaker connected (to avoid panic about output DC offset).

Setting it right:
We want about 1A through JFETs (set with value of R2, start with 2R2 - lower resistance will give higher current) and about 10V (half of the V1) at the drain of Q1 (set with value of R1, start with 2R2).
If it happens that you have DC offset at input it means that your Q1 has a leaky gate but it's not a big deal, just use coupling cap at input (22u or so).
Don't forget to take good care about heatsinking Q1 and Q2 or, if you can't, lower the V1 to 15V or even 12V - it will still produce 1W at the output. If you have 16R speakers you can lower the current through Q1 and Q2.
PSRR is very good so no extra care has to be taken about power supply, simple CRC will do fine.
Attached Images
File Type: jpg LU1014-FAOW.jpg (16.4 KB, 404 views)
__________________
Please don't use private messages for question related to audio projects. It defeats the purpose of the forum.

Last edited by juma; 19th July 2018 at 10:20 AM.
  Reply With Quote
Old 19th July 2018, 11:03 AM   #93
Rodeodave is offline Rodeodave  Austria
hates ground loops
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
FAOW
Can we do something like Figure 4 from Zen Variations#8?
Attached Images
File Type: jpg 20180719_125937~01.jpg (58.1 KB, 391 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 19th July 2018, 11:46 AM   #94
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
http://www.6moons.com/industryfeatures/zen8/11.gif


Patrick
__________________
xen-audio.com
  Reply With Quote
Old 19th July 2018, 12:00 PM   #95
Rodeodave is offline Rodeodave  Austria
hates ground loops
diyAudio Member
 
Rodeodave's Avatar
 
Join Date: Dec 2004
Location: in the alps
FAOW
This is what I'm referring to:
Attached Images
File Type: png VrpqeEr.png (22.3 KB, 383 views)
__________________
Gravity - Making the G since 13.7 billion B.C.
  Reply With Quote
Old 19th July 2018, 12:06 PM   #96
coolnose is offline coolnose  Europe
diyAudio Member
 
coolnose's Avatar
 
Join Date: Sep 2009
Just shout "iron" and ZM will pop up just like by miracle...
  Reply With Quote
Old 19th July 2018, 06:58 PM   #97
nicoch58 is offline nicoch58  Europe
diyAudio Member
 
Join Date: Oct 2004
  Reply With Quote
Old 19th July 2018, 06:59 PM   #98
Vix is offline Vix  Yugoslavia
diyAudio Member
 
Vix's Avatar
 
Join Date: Nov 2003
Location: Somewhere on Planet Earth
Thanks Juma.
Although I must confess that I have a fetish for lightbulbs, so I may be inclined to use one instead of the upper Jfet
  Reply With Quote
Old 19th July 2018, 07:31 PM   #99
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
FAOW
Quote:
Originally Posted by Vix View Post
A question for Nelson: if you were to build a simple 1w amp witj Lu1014 j-fet, what would you do? I am thinking of something extremely simple, just for fun, something along the lines of Zen V8, but without the cascode, and maybe with a lightbulb
Will it work, or will it Pop?
The problem with the Lu1014 is that I have not had good success making
it behave itself outside of a cascoded situation, and stopped trying after
a while.

But seeing as I have about 7000 of them, maybe I should take another
look.
  Reply With Quote
Old 19th July 2018, 08:38 PM   #100
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
I saw a German SRPP quite some years ago using a pair of LU1014 on 18V rails.
Could not find it anymore.
There is a Chinese website posting something similar.
But I could not recall whether the two are identical or not.

http://f1.hifidiy.net/forum/forumid_...dd3fe97d50.jpg


Patrick
__________________
xen-audio.com
  Reply With Quote

Reply


FAOWHide 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

Forum Jump


New To Site? Need Help?

All times are GMT. The time now is 04:23 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki