L'Amp: A simple SIT Amp - Page 44 - 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 19th January 2012, 07:06 PM   #431
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
with so big caps at fist position we have a big current pulse,rfi, better put a small resistor for more conduction angle.....
__________________
Sic58

Last edited by nicoch58; 19th January 2012 at 07:09 PM.
  Reply With Quote
Old 19th January 2012, 07:23 PM   #432
diyAudio Member
 
juanitox's Avatar
 
Join Date: Dec 2006
like a 0,5 ohm ?
__________________
French is not a crime.
  Reply With Quote
Old 19th January 2012, 07:37 PM   #433
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
yes 0.1 to 0.5,try test on PSUD software...
__________________
Sic58

Last edited by nicoch58; 19th January 2012 at 07:39 PM.
  Reply With Quote
Old 19th January 2012, 07:54 PM   #434
diyAudio Member
 
Join Date: May 2001
Blog Entries: 5
More cowbell, maybe.
  Reply With Quote
Old 19th January 2012, 09:13 PM   #435
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Quote:
Originally Posted by Tea-Bag View Post
Gerd,
What brand, how many of what wattage thick film resistors. I have thought about parralleling a few 100W thick film types.
Hi tea-bag,

they are Vishay, I cannot get them here in 100W so I took 50W and 4x10 Ohm in series and parallel gives 10 Ohm and one 2,2 Ohm and one 1 Ohm and I get the chain of 13,2 Ohm I need with the 45-48V DC an 2x18V AC xformer from my FW PSU can make......

the sound its really a big change now I can understand the BTW was speaking of "tube rolling" ; I made resistor rolling........

my battle between resistor solution and Mufollower is still not decided ...

not to speak of the Salas CCS..

RTO 50F 47 - Dickschichtwiderstand 50W TO220 47 Ohm, 5 - Dickschichtwiderstände TO220 bei reichelt elektronik
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 19th January 2012, 09:23 PM   #436
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
juanitox,

I am sorry to hear about your hum, after I got away from the + -24V arrangement from the First Watt PSUs, and built it like Mike suggested with 48V I have no hum, only going to the speaker very close I can hear a little bit....

unfortunately i have no good idea what you should do,

when the hum is induced by the bias voltage you could try a nine Volt block instead for a moment, may be the hum is over.....
you will be happy about your thick film resistors....

and there must be a simple solution for your hum.....
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 19th January 2012, 09:49 PM   #437
diyAudio Member
 
juanitox's Avatar
 
Join Date: Dec 2006
for this week my Sit is dead , cause i killed the bridge rectifier with a bad live action ... so waiting for the new ones , i hve time to re-thinking my Amp Config.. it's better when it"s not working to fast
__________________
French is not a crime.
  Reply With Quote
Old 19th January 2012, 09:51 PM   #438
diyAudio Member
 
Join Date: May 2001
Blog Entries: 5
Take your time. It's a journey. We'll all still be here.
  Reply With Quote
Old 19th January 2012, 10:04 PM   #439
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Yes, I can send you two from Germany maybe faster....

I have an idea, I would build only one channel with no extras, only main function to isolate the guilty part.


Oh rereading your posting you did not kill the SIT, but the bridge rectifier.... So no need to send you a part I suppose...
__________________
and the First Wtt is......a really First Class PSS Idea

Last edited by generg; 19th January 2012 at 10:21 PM.
  Reply With Quote
Old 20th January 2012, 02:11 AM   #440
diyAudio Member
 
Join Date: May 2001
Blog Entries: 5
I pulled up my notes:

The resistor / lightbulb version measured 70 nanowatts noise + hum. With 101 dB speakers @ 2 meters distance that would be around 23 dB, or somewhere between a really quiet room and a faint whisper.

Forgive me for quoting the wrong units earlier (uV). I was away from my underground lair.
  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
L’Amp: A Simple SIT Amp: Part 1 Michael Rothacher diyAudio.com Articles 23 1st September 2014 02:02 AM
SIT Amp Article Out Now Variac Site Announcements 0 2nd December 2011 08:55 AM
Srajan has the 1st SIT amp for Une dégustation vizion Pass Labs 131 15th November 2011 12:41 AM
SIT-Preamp VladimirK Solid State 36 27th August 2011 09:36 PM
New SIT - old problem StevenOH Parts 2 13th June 2008 11:46 AM


New To Site? Need Help?

All times are GMT. The time now is 04:18 AM.


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