BOSOZ rail voltage - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 20th July 2004, 02:10 PM   #1
pro is offline pro  Italy
diyAudio Member
 
pro's Avatar
 
Join Date: Feb 2004
Location: Milano
Default BOSOZ rail voltage

Some one knows what is, at the listening, the differences by running Bosoz at +-30V and at +-60V?
Ciao.
__________________
Michele
  Reply With Quote
Old 20th July 2004, 04:03 PM   #2
eLarson is offline eLarson  United States
diyAudio Member
 
eLarson's Avatar
 
Join Date: Aug 2002
Location: Gaithersburg, MD
I run mine at +/-30... and the -30 is rather wasteful on my part since I use constant current sinks to hold the current as steady as possible. I love the sound of it.
__________________
Would a woodchuck bother to chuck MDF?
  Reply With Quote
Old 20th July 2004, 05:08 PM   #3
diyAudio Member
 
Alain Dupont's Avatar
 
Join Date: Sep 2003
Location: Paris - France
pro,

Look at the balzenpre.pdf file, Nelson explains distorsion for different rail voltages...

Figure 11 shows the THD & noise, again for four different rail voltages.
The output is at 2 volts and is plotted versus frequency. The figure is the
same from 20 Hz to 20 KHz.

Regards.

Alain.
Attached Images
File Type: jpg thd&noise.jpg (37.4 KB, 150 views)
  Reply With Quote
Old 20th July 2004, 05:22 PM   #4
pro is offline pro  Italy
diyAudio Member
 
pro's Avatar
 
Join Date: Feb 2004
Location: Milano
Thanks Alain, I already knew the difference in TDH, but my question is another one: in a listening test, how is it effected from this difference in tdh+noise?
Thanks
Ciao.
__________________
Michele
  Reply With Quote
Old 20th July 2004, 06:09 PM   #5
diyAudio Member
 
Alain Dupont's Avatar
 
Join Date: Sep 2003
Location: Paris - France
Pro,

>> in a listening test, how is it effected from this difference in tdh+noise?

Well, good measures do not define good sound.
If you use lower rails, but with higher bias, it somehow compensates.

I have built a CCS-X-BOSOZ, and in my listening tests higher voltage & higher bias gave better definition, for 60 volts on the upper part of the 2 * IRF610 and 40 to as much as 60 mA bias for each MosFet.

The results:
Better micro dynamics, wider soundstage, and greater depth.

PS:
I plan to make tests with 70 volts rails ; my only problem is to dissipate
a lot of heat on the 2 * 750 Ohms {3 watts} drain resistors...

At this time I have built and stuffed all Pcb's for the ccs-x-bosoz, the Apox circuits are completed ; it remains the enclosures to built or buy...

Regards.

Alain.
  Reply With Quote
Old 20th July 2004, 06:50 PM   #6
pro is offline pro  Italy
diyAudio Member
 
pro's Avatar
 
Join Date: Feb 2004
Location: Milano
Thank you Alain.
I'll plan a 60V reil.
Why don't you try to use those Vishay resistor. They ar rated 50W on hetsink, but can also dissipate 5.5W without, so that you can just attach them to the bottom of the case. Ther is the 1K2 value that is good for 58 ma at 70V (4.2W).
I am planning to use a case of a Rotel pre that I have already modified meny times. For now, i am using his power supply, very well made, but for the bosoz I mast change avery thing because the PS is only 27V unregulated. I just want to use the input
selectors unbalanced and the motorized volume control, a very good Alps 50K blue series to use on the output of the bosoz, so I can use it
that is a double pot and not quadruple. Also veri good is the mute section that puts output to ground when I switch it on and off, and when I push the dedicated button (also from remote control).
For balanced input I'll see. Not balanced output at moment, because my Zen V4 is steel unbalanced.
Let me know wath do you think abaut.
Ciao.
Attached Images
File Type: jpg 50w.jpg (19.4 KB, 139 views)
__________________
Michele
  Reply With Quote
Old 20th July 2004, 07:21 PM   #7
diyAudio Member
 
Alain Dupont's Avatar
 
Join Date: Sep 2003
Location: Paris - France
Pro,

Good idea about the Wishay resistors, the only thing
is that they are big... I would like to minimise parasitic capacitance in particular.

I have placed holes underneath to have better ventilation...

Will try Wishay 10 watts in a future version...
Attached Images
File Type: jpg ccs-x-bosoz04.jpg (67.4 KB, 169 views)
  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
rail voltage mike49504 Car Audio 3 11th November 2008 06:12 PM
A40 Rail Voltage gpsmithii Pass Labs 29 19th April 2006 05:01 PM
bosoz rail voltages EANDERS Pass Labs 2 25th March 2005 04:19 PM
Rail Voltage to Capacitor Voltage Mermprin Parts 6 20th September 2004 03:56 PM
Rail voltage compared to transformer voltage SteveG Solid State 4 22nd July 2002 11:50 PM


New To Site? Need Help?

All times are GMT. The time now is 05:21 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