Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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 24th January 2009, 07:51 PM   #751
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by ikoflexer
I tested the LED version as well and it works as per this attachment. Tested with both bf245a and sk170 jfets; my scope does not show a difference between the two. Perhaps there is sound wise, but I don't have phono circuit done yet. Nice to see the filtered input trace swing up when some power device in the house turns on and off in the house, but the regulated does not move. Neato!

Contents of sreg10.zip
sreg10bottom.pdf
sreg10silkscreen.pdf
salasshunt10.pcb
Don't expect to see such noise subtleties on o scope. It takes an FFT with well sorted out loop gnd and -120 to -130dB noise floor so to see what version rises higher as the frequency goes up. The LEDS need 5-10mA to be fair with their noise capabilities. I use my strongest IDSS matching left over 2SK170BL always there.

As for what you saw for low line noise and transient susceptibility, its something I forgot to mention I think, but yes, it works much better for isolation than the (series & feedback) LM317 that I earlier had.
  Reply With Quote
Old 24th January 2009, 07:58 PM   #752
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Quote:
Originally posted by salas


We must clarify the alternatives for the CCS Voltage reference and their configuration here:
...
Excellent! I'll save this for tuning things up.
  Reply With Quote
Old 24th January 2009, 08:03 PM   #753
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by ikoflexer
Nice to see the filtered input trace swing up when some power device in the house turns on and off in the house, but the regulated does not move. Neato!
Hey! Were are the crocodile wired PSU on dirty bench pictures with oscilloscope bright green traces in the background? We want DIY porn!
  Reply With Quote
Old 25th January 2009, 12:18 PM   #754
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by es44
I'm finally finished with my first attempt

Did the 36dB version, but need a little more gain, so next one will be the 46dB. It seems i can just lift the voltage 4 volts, and change a few resistors. Should be easy. ( well, at least for some, i always find a way to mess up, hehe )

Thanks for making this possible Salas.

Click the image to open in full size.
You can even bypass R1 (the 100R resistor under first stage JFET) with a 1000uF Panasonic FC or Elna Silmic or Black Gate NX 6.3V and it will become 41dB gain without further changes.
  Reply With Quote
Old 25th January 2009, 01:01 PM   #755
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by salas
it will become 41dB gain without further changes.
Wrong. 44dB it will become.


  Reply With Quote
Old 25th January 2009, 02:31 PM   #756
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Quote:
Originally posted by salas


Hey! Were are the crocodile wired PSU on dirty bench pictures with oscilloscope bright green traces in the background? We want DIY porn!

Ah, sure, but it'll have to be a little later, I've been away from the hobby busy with "life."
  Reply With Quote
Old 25th January 2009, 04:24 PM   #757
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Default 28V Led Shunt

Hi Salas

To feed 33V into the shunt, can I use a 24V TX 50VA ?

Should I build two shunts (one for each channel) or is it overkill ?

Ricardo
__________________
RC
  Reply With Quote
Old 25th January 2009, 05:33 PM   #758
AndrewT is offline AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
if you want to use two shunts then you'll get the best out of them by having dual secondaries. This can be separate transformers one to each channel or a dual secondary with an isolated winding to each channel.

If you are building a dual polarity version then you need dual polarity supplies. This will require four isolated secondary windings.

It is normally recommended that Vac ~= regulated Vdc.
However these shunt regulators are approaching low voltage drop out (LDO) performance, so we can manage with a bit less on the AC side.
For 33Vdc use either 28Vac or 30Vac and with dual rectifiers use 28 or 30-0, 28 or 30-0
__________________
regards Andrew T.
  Reply With Quote
Old 25th January 2009, 06:20 PM   #759
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
Thank you Andy

Your explanation was perfect

Regards

Ricardo
__________________
RC
  Reply With Quote
Old 25th January 2009, 07:18 PM   #760
RCruz is offline RCruz  Switzerland
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Blog Entries: 1
So if I use a 30Vac TX, the rectfiers bridge will bring it to ~41Vdc.... Salas 28v schunt schematic indicates +33Vdc on input.... does the difference matter ?

Sorry if it sounds very noob
__________________
RC
  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



New To Site? Need Help?

All times are GMT. The time now is 03:40 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