Simplistic Mosfet HV Shunt Regs - Page 370 - diyAudio
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 24th December 2012, 06:31 PM   #3691
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by roger57 View Post
Why manual...when "automatic" is available for us lazy types??
Click the image to open in full size.

Hey Roger57, Merry Xmas. Did you get the chance to audition your amps mods by now?
  Reply With Quote
Old 24th December 2012, 10:28 PM   #3692
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
Hi Salas!

Merry Christmas to you in beautiful Greece!

I just completed the modifications today and have only listened for a couple of hours. So far, terrific! Recall I have 2 identical Class A amplifiers in passive bi-amp mode on my speakers. The amplifier I modified was the high frequency unit. I find the high frequencies have better resolution and linearity. Extremely nice placement and clarity of vocals. It did what I expected.

However, I ended up having to back off the total current being delivered by the screen regulator. Recall that I required 60mA to the screens at full power output. With the screen current being dynamic, and this unit the high frequency amplifier, I could afford to back the current down to keep the heat sink under 50C, in spite of it's size! I now have adjusted the total current at the test point for 65mA. So far in listening, I believe this will be adequate given the volume I listen at. There are 2 SSHV2 units and a filament regulator all bolted to the same heat sink, so there's a lot of dissipation happening there! I will need to increase the heat sink size on the low frequency amplifier as I will need all the screen current there. No problem as I have more of the same heat sink material and the room on the baseplate to install it. I'll take a couple of pictures later in the week when I have it back in to do some final small updates.

My best wishes to you for a great 2013, and thanks again for everything you do for all who are a part of these forums. It means a lot!

Gary

Last edited by roger57; 24th December 2012 at 10:31 PM.
  Reply With Quote
Old 25th December 2012, 07:19 PM   #3693
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
A good first impression is 50% chance to sure success. Congrats. More details and few pics as it settles we guess. Merry Xmas.
  Reply With Quote
Old 26th December 2012, 02:07 AM   #3694
diyAudio Member
 
Join Date: Apr 2011
...thankyou for all the helps....I have finished changing Q4, Q5 and the 117 on the questionable board mentioned...I have also renew all the solder joints....I have also added small heat sink with fins to each of the Q4 &5....the 2 boards are now doing 279V in....30mA at TP, and 260V out, with 48V across the 6K loading resistors......they have been steady for more than an hour.....but the Q4 and 5 are still quite hot....and when I blow on them...the V out jumps to 265...it is normal like this??.....I am thinking of adding a piece of aluminum strip the the sink

The photos show the two board installed (no sink yet seen with the Q4 & 5)
Attached Images
File Type: jpg P1140614.jpg (469.3 KB, 223 views)
File Type: jpg P1140615.jpg (371.0 KB, 213 views)
  Reply With Quote
Old 26th December 2012, 03:01 PM   #3695
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
IMO, these are the minimum size you should install on the 2 transistors (Q4,Q5)

274-2AB Wakefield Thermal Solutions | 345-1087-ND | DigiKey
  Reply With Quote
Old 26th December 2012, 03:04 PM   #3696
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
Default Website Issues?

Salas,

I see you're a forum moderator. Are you aware of any website issues with DIY Audio? Whenever I try to post anything, (the last 3 tries anyhow) I get a warning page from Firefox / Google saying this is a reported "Attack" website.

Know anything about this?

Gary
  Reply With Quote
Old 26th December 2012, 03:18 PM   #3697
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
Attack is ok now ,just a little bit of time to google to reload...
__________________
Sic58
  Reply With Quote
Old 26th December 2012, 03:22 PM   #3698
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
info
http://www.diyaudio.com/forums/forum...ml#post3299614
__________________
Sic58

Last edited by nicoch58; 26th December 2012 at 03:24 PM.
  Reply With Quote
Old 26th December 2012, 04:12 PM   #3699
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Quote:
Originally Posted by king4joy View Post
....and when I blow on them...the V out jumps to 265...it is normal like this??.....I am thinking of adding a piece of aluminum strip the the sink

The photos show the two board installed (no sink yet seen with the Q4 & 5)
Nice photos. When you blow there, yes its normal to drift. There is no ventilation there in your build, so help them Q4 Q5 out with sinking when able.
  Reply With Quote
Old 26th December 2012, 05:16 PM   #3700
roger57 is offline roger57  Canada
diyAudio Member
 
roger57's Avatar
 
Join Date: Sep 2006
Location: Edmonton, Alberta
Quote:
Originally Posted by nicoch58 View Post
Hey, thanks for providing this information. It helps to know what's going on and I'm not the only one seeing this!
  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
Regs - Shunt vs Series richie00boy Solid State 42 14th March 2013 06:45 PM


New To Site? Need Help?

All times are GMT. The time now is 07:31 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