Go Back   Home > Forums > Amplifiers > Power Supplies

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 12th June 2009, 02:52 AM   #461
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Ah, very nice indeed! Well done James, thank you!

James, how would somebody print just the silk screen?

Salas, for me, being new to the whole audio thing, I lack the experience you have in voicing various parts, so, I try to help how I can. I don't have a reference system yet to do proper listening experiments, but once I finish a high voltage regulator for the tube headphone amp, then I should be able to do it. I was hoping that people like you, who have trained ears, will at some point try one of the promising versions and reports the findings. But I'm aware that it takes a lot of time and effort to try new circuits, and people are skeptical of new, untried circuits.
  Reply With Quote
Old 12th June 2009, 03:13 AM   #462
Tham is offline Tham  Malaysia
diyAudio Member
 
Join Date: Jun 2006
Hi Salas,

Hooked up my first V1 built to a Le Pacific RIAA variant using regular quality components and heard loud hum from both speakers. It measures 24.6 V on load.

Do not have similar problem with my linear regulator. What could have I done wrong?
  Reply With Quote
Old 12th June 2009, 03:21 AM   #463
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
It works but the CCS not, so it passes ripple, is one scenario.

Are your Mosfets both hot?

Another scenario is that the BC550 you had to reverse, was killed when put wrong.
  Reply With Quote
Old 12th June 2009, 03:25 AM   #464
Tham is offline Tham  Malaysia
diyAudio Member
 
Join Date: Jun 2006
Ok. Will change the BC550 on board and test again...
  Reply With Quote
Old 12th June 2009, 03:29 AM   #465
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
But you did not answer about scenario #1. Are your Mosfets both correctly working? See their Vgs, see Voltage drop on R1. (If BC550 was not the problem.)
  Reply With Quote
Old 12th June 2009, 03:33 AM   #466
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
Yes, as salas mentioned, check with the diode tester on your dmm the npn.

You may want to hook up a power resistor of about 500ohm and test it that way. Sanity checks:
* voltage between base and emitter pins of the BC550 should be around 0.66V
* voltage between gate and source on each mosfet should be around 4V
* voltage before the series mosfet should be more than 24V in your case, probably 26 and up
* add a small 1ohm, 2ohm, 0.5ohm or similar resistor between the drain of the shunt mosfet and ground, and check the voltage across it, then divide by the value of the resistor, and see what the current through the shunt is

Good luck, let us know how it pans out.
  Reply With Quote
Old 12th June 2009, 03:38 AM   #467
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Iko,

No offence ment but some of my prototypes look worse than yours. Mr.Pass showed me how to do it in the A40 diy article.

Jam
  Reply With Quote
Old 12th June 2009, 03:47 AM   #468
iko is offline iko  Canada
diyAudio Moderator
 
iko's Avatar
 
Join Date: May 2008
Location: Toronto
None taken. You mean this?
http://passdiy.com/pdf/a40.pdf

on page 9? Wow, 1978!

I like prototyping, no pressure to make it pretty (except when salas asks for pictures )
  Reply With Quote
Old 12th June 2009, 03:53 AM   #469
jam is offline jam  United States
diyAudio Member
 
jam's Avatar
 
Join Date: May 2001
Location: Auburn, CA, USA
Yep.......that's the one. Boy I must be getting old. Mr.Pass was a pioneer back then.

Jam

P.S. by the way that amp isn't half bad even by today's standards.
  Reply With Quote
Old 12th June 2009, 04:08 AM   #470
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally posted by ikoflexer
James, how would somebody print just the silk screen?
Click the image to open in full size.
  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 08:40 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