Go Back   Home > Forums > >

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

Simplistic NJFET RIAA
Simplistic NJFET RIAA
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
Old 23rd January 2021, 08:24 AM   #18731
SKA76 is offline SKA76
diyAudio Member
 
Join Date: Nov 2014
Quote:
Originally Posted by Salas View Post
50VA Antek which is very much used by American builders has magnetic shield that their lesser VA models don't have is another reason why usually recommending 50VA
A Polish manufacturer of toroidal transformers offers shielded transformers starting from 20 VA. Which VA rating would be your primary choice for a pair of transformers (230V) for this project?

Thanks!
  Reply With Quote
Old 23rd January 2021, 03:35 PM   #18732
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Simplistic NJFET RIAA
30VA-50VA each
  Reply With Quote
Old 25th January 2021, 05:05 PM   #18733
SKA76 is offline SKA76
diyAudio Member
 
Join Date: Nov 2014
Thanks Salas!

How do I wire the 32 V primaries of the 2 transformers to one IEC (230 V)?
Usually one of the primaries is tagged with a tape at the end (indicating the inner winding?).

Thanks!
  Reply With Quote
Old 25th January 2021, 07:15 PM   #18734
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Simplistic NJFET RIAA
32V can't be primaries but secondaries. Primaries should be 115V each. Depends on each brand. Could be connecting two tagged or specifically colored ones together and the side ones to the mains. But better look it up at the manufacturer's website.
  Reply With Quote
Old 26th January 2021, 08:23 AM   #18735
SKA76 is offline SKA76
diyAudio Member
 
Join Date: Nov 2014
Thanks Salas!
Luckily, I did not mix up primaries and secondaries in real life

The background of my question was if it is necessary to use 2 fuses with 2 transformers as suggested in this thread: Wiring up two trafos to one IEC socket.

Which slow blow fuse(s) should I use (230 V), 1.25 A?

Thanks!
  Reply With Quote
Old 26th January 2021, 11:27 AM   #18736
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Simplistic NJFET RIAA
Its not necessary to use individual primary fuses by electrical safety code. In case you want to, you should not skip a central fuse. In other words 2.5A in the IEC socket and 1.25A before each 50VA transformer for USA. Cut those figures to nearest 1/2 available amperage values for Europe and other 230V countries. All such fuses should be time lag (T) type. What we call slow blow.
  Reply With Quote
Old 27th January 2021, 09:58 PM   #18737
cygnus x1 is offline cygnus x1  United States
diyAudio Member
 
Join Date: Sep 2006
The ultra is using PF5102 fets? I can't find a data sheet that specifies the noise figure, any clues?
  Reply With Quote
Old 28th January 2021, 12:02 AM   #18738
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Simplistic NJFET RIAA
PF5102s are strongly related to the J11/112/113 family. Look in their datasheet page 5 figure 14: J/MMBF
  Reply With Quote
Old 28th January 2021, 03:09 PM   #18739
cygnus x1 is offline cygnus x1  United States
diyAudio Member
 
Join Date: Sep 2006
Thanks!
  Reply With Quote
Old 3rd February 2021, 01:07 AM   #18740
elwood625 is online now elwood625  United States
diyAudio Member
 
elwood625's Avatar
 
Join Date: Jan 2013
Location: Elkhart Lake, WI
Hello Salas and Tea-Bag, I finished my preamp with BA2018 line stage boards stacked for Balanced operation with the UFSP with shunt regulators in the same chassis. The power supplies for the display/ relay input /volume control/remote, has a 250vac 30A relay to turn on the power supply for the BA2018 line stages.
The UFSP has a remote power supply with umbilical cord, the shunt regulators are mounted vertical with the home made heat sinks 10mm below the vents in the steel chassis. After 3 hours of operation, the inside of the enclosure stayed the same temperature. It is dead quite on all of the inputs, the UFSP I've adjusted and played HO MM, LO MC, HO MC. After a month of playing, time to move it into the main system.


Thank you both for all your help with this project!
Attached Images
File Type: jpg IMG_1683.jpg (984.7 KB, 171 views)
File Type: jpg IMG_1693.jpg (753.5 KB, 169 views)
File Type: jpg IMG_1691.jpg (859.1 KB, 161 views)
File Type: jpg IMG_1688.jpg (778.1 KB, 152 views)
  Reply With Quote

Reply


Simplistic NJFET RIAAHide this!Advertise here!
Thread Tools

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


New To Site? Need Help?

All times are GMT. The time now is 04:40 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki