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.

sound of a constantcurrentsource for BSOZ?
sound of a constantcurrentsource for BSOZ?
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
Thread Tools Search this Thread
Old 23rd October 2001, 08:09 PM   #1
joe is offline joe  Germany
diyAudio Member
Join Date: Oct 2001
Location: Hamburg
at the moment i am making a layout for the Bal.Linestage and i am thinking about to use one or two CCS instead of the resistors to bias the FETs. Does somebody has any (listening) experience with that? When using a CCS is it possible to reduce the neg. railvoltage to, lets say -15V or even to zero? Would you recommend a simple FET+Resistor-type for the CCS or a more sophisicated design? With respect to noise it might be better (i think) to use only one CCS to bias both FETs, Nelson Pass uses one CCS for each FET in his commercial designs. Is there a difference in sound?

Thank you

  Reply With Quote
Old 23rd October 2001, 09:22 PM   #2
Nelson Pass is offline Nelson Pass  United States
The one and only
Nelson Pass's Avatar
Join Date: Mar 2001
sound of a constantcurrentsource for BSOZ?
I haven't found a lot of difference in actual sound
between the variations of current sources. A current
source is preferred, but has not been used in some of
the Zen projects because of the additional complexity.

The biggest difference is that the input common mode
rejection with balanced inputs is very much better
with current sources, and with an unbalanced signal, the
current source gives lower distortion.

Dual current sources, one for each of the input devices
allows for an arbitrary amount of resistance to be
inserted between the Source pins of the differential
circuit without concerns about altering the DC point.
On the Aleph P circuit, the resistance was made adjustable,
which allowed gain trim and also higher input overload
when set to higher values.

The choice of JFET current sources vs MOSFET vs Bipolar
comes down to what works best at various current and
voltage levels. When the voltage and current is high,
I usually use MOSFETS. If the voltage and current is
low, JFETs, which are simpler and quieter.
  Reply With Quote


sound of a constantcurrentsource for BSOZ?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
BSOZ Question- Caps and Rs lgreen Pass Labs 3 10th July 2003 02:46 PM
can somebody convert the BSOZ gerberfile to something usable??? hifi Pass Labs 20 5th January 2003 05:23 PM
Irf520N for BSOZ? CH2 Pass Labs 3 18th December 2002 09:38 AM
BSOZ using R15 & P5 as volume control Super_BQ Pass Labs 1 12th August 2002 07:31 PM
Some Q about BSOZ Powersupply hifi Pass Labs 20 31st December 2001 10:13 PM

New To Site? Need Help?

All times are GMT. The time now is 07:47 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio