Rectifier diode noise in CCS and biasing

wleediy · 24th January 2008, 10:27 AM

In the last 2 years I have found that all the electrinics sounded much better when the rectifiers were being changed from the 1N4007 type to the eqv FR type. I have not tried to listen to Schottky, though I have used SBL3045PT to supply DC to EL519 2.5A filament with good result.
Now looking at the CCS and biasing circuit in power amps, there are ample 1N400X type being used. Has any one listen to the diff in sound when those were being replaced by the FR type? I am hesitating as the typical FR type has a lower forward voltage drop which is typically 0.45V which is at least 0.1V lower then the regular 1N type. So in the CCS that will require readjustment of the current flow.
Also, how is the latest opinion on the Schottky diode? There were quite a few who felt that the sound may not be as warm as the FR type.

best rgds

William

Ouroboros · 24th January 2008, 10:30 AM

The audible difference in rectifiers between a standard 1N400X or 1N540X type and high-speed, soft-recovery diodes is in the considerable reduction in switching noise generated by the diode because of the minimisation of the reverse current 'snap-off' transition. If a diode is used in a continuous forward-biased mode, to produce a defined voltage in a bias supply for example, this source of noise isn't present.

wleediy · 24th January 2008, 11:01 AM

I see, tks! How about in the case that when they are being used as the bias in the power amp, for example at the output of Op amp output to drive a complimentary pair of driver transistor. So that he -ve phase drives the NPN and +ve phase drives PNP. As the signal is not DC, will there be noise problem? Will diode like 1N4148 has lower noise?

rgds

William Lee

24th January 2008, 10:27 AM	#1
wleediy diyAudio Member Join Date: May 2004 Location: Singapore	Rectifier diode noise in CCS and biasing In the last 2 years I have found that all the electrinics sounded much better when the rectifiers were being changed from the 1N4007 type to the eqv FR type. I have not tried to listen to Schottky, though I have used SBL3045PT to supply DC to EL519 2.5A filament with good result. Now looking at the CCS and biasing circuit in power amps, there are ample 1N400X type being used. Has any one listen to the diff in sound when those were being replaced by the FR type? I am hesitating as the typical FR type has a lower forward voltage drop which is typically 0.45V which is at least 0.1V lower then the regular 1N type. So in the CCS that will require readjustment of the current flow. Also, how is the latest opinion on the Schottky diode? There were quite a few who felt that the sound may not be as warm as the FR type. best rgds William

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
NP recommended rectifier diode?	calvert73	Pass Labs	11	8th September 2010 09:46 PM
Tube rectifier to diode	bereanbill	Tubes / Valves	19	19th May 2009 11:37 PM
BYV79E as rectifier diode	tubee	Solid State	5	18th June 2008 02:45 PM
diode rectifier ratings	redrabbit	Power Supplies	8	13th November 2006 05:33 AM
Rectifier diode for Non-os Dac	tonitze	Digital Source	0	24th August 2003 04:33 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	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

24th January 2008, 10:30 AM	#2
Ouroboros diyAudio Member Join Date: Dec 2003 Location: Nottingham UK	The audible difference in rectifiers between a standard 1N400X or 1N540X type and high-speed, soft-recovery diodes is in the considerable reduction in switching noise generated by the diode because of the minimisation of the reverse current 'snap-off' transition. If a diode is used in a continuous forward-biased mode, to produce a defined voltage in a bias supply for example, this source of noise isn't present.

24th January 2008, 11:01 AM	#3
wleediy diyAudio Member Join Date: May 2004 Location: Singapore	I see, tks! How about in the case that when they are being used as the bias in the power amp, for example at the output of Op amp output to drive a complimentary pair of driver transistor. So that he -ve phase drives the NPN and +ve phase drives PNP. As the signal is not DC, will there be noise problem? Will diode like 1N4148 has lower noise? rgds William Lee

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)