Simplistic NJFET RIAA - Page 853 - diyAudio
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 19th November 2012, 03:17 PM   #8521
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by Doug R View Post
Also, Salas, when I hooked up the raw supply to the reg, I connected the raw ground to Force negative. That is right isn't it?

Also, the ground is floating, i.e. not connected to earth, since it is on a breadboard.

Doug
Yes that is right.

Floating GND or not its no make or break condition for getting it running.
  Reply With Quote
Old 19th November 2012, 03:18 PM   #8522
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by Doug R View Post
Hey Guys,
I am sure I switched the drain and source when I wired the MOSFETS.
Going to change them now.

Doug
Here is the part where B. Spears enters the scene and sings ooops!
  Reply With Quote
Old 19th November 2012, 03:24 PM   #8523
Doug R is offline Doug R  United States
diyAudio Member
 
Join Date: Oct 2007
Location: Indy
Update:
After fixing the MOSFET pin wiring,

1. I have voltage in and out. Didn't have good solder joint at Vin turret. Doh!

2. It does't regulate. Vin = Vout (39.5 volts) regardless of pot setting from min to max R.

3. LEDs light up, although the third one is not as bright as the other two.

3. Read some voltages at MOSFET Pins:
For Q1, gate = 34.9 V source and drain = 39.4 V
For Q4 gate and source - 39.4 V, Drain = 0 volts.

My probe slipped, briefly shorting S and D on Q4.

Any suggestions.
  Reply With Quote
Old 19th November 2012, 03:26 PM   #8524
Doug R is offline Doug R  United States
diyAudio Member
 
Join Date: Oct 2007
Location: Indy
Salas: do you actually listen to Brittany Spears?
  Reply With Quote
Old 19th November 2012, 03:27 PM   #8525
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
You made much progress though. Now, with DMM in DCV each Mosfet must have ~4V between G & S pin, every BJT must have ~0.6V between B & E pin. Do they?
  Reply With Quote
Old 19th November 2012, 03:29 PM   #8526
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by Doug R View Post
Salas: do you actually listen to Brittany Spears?
I was watching rather than listening when the odd clip was on TV. She had kinda "rounded" musical culture that I tend to appreciate in female artists.
  Reply With Quote
Old 19th November 2012, 03:37 PM   #8527
Doug R is offline Doug R  United States
diyAudio Member
 
Join Date: Oct 2007
Location: Indy
I guess "musical culture" has a different meaning in Athens. ")

I will go check voltages after I finish my ravioli with pesto. Yum.
  Reply With Quote
Old 19th November 2012, 04:02 PM   #8528
Doug R is offline Doug R  United States
diyAudio Member
 
Join Date: Oct 2007
Location: Indy
OK, I get
Q1 MOSFET 4.7 V
Q4 MOSFET 3.5 V

Q3 BJT 27.6 V
Q6 BJT 0.63 V
Q7 BJT 0.33 V

Q2 2SK170 0.0
Q5 BF245B 0.0 V
  Reply With Quote
Old 19th November 2012, 04:05 PM   #8529
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Q3 must have got a raw deal. Change that for starters.
  Reply With Quote
Old 19th November 2012, 05:00 PM   #8530
Doug R is offline Doug R  United States
diyAudio Member
 
Join Date: Oct 2007
Location: Indy
OK. Changed Q3

Q1 G to S = 3.3 V
Q4 G to S = 3.5 V

Q3 B to E = 0.7 V
Q6 B to E = 0.6 V
Q7 B to E = 0.7 V

Q5 G to D = 0.7 V
Q2 G to D = 3.5 V
  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 05:43 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