F5 pcb group buy... - Page 52 - diyAudio
Go Back   Home > Forums > Commercial Sector > Group Buys

Group Buys Members group buys

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 29th July 2010, 05:20 PM   #511
diyAudio Member
 
Peter Daniel's Avatar
 
Join Date: Jul 2002
Location: Toronto, Canada
Send a message via AIM to Peter Daniel
I did some measurements how bias stabilizes in my amps (without thermistors): F5 pcb group buy...
__________________
www.audiosector.com
“Do something really well. See how much time it takes. It might be a product, a work of art, who knows? Then give it away cheaply, just because you feel that it should not cost so much, even if it took a lot of time and expensive materials to make it.” - JC
  Reply With Quote
Old 29th July 2010, 05:23 PM   #512
Tea-Bag is offline Tea-Bag  United States
not politcally affiliated
diyAudio Member
 
Tea-Bag's Avatar
 
Join Date: Feb 2006
Location: Kennebunk
Blog Entries: 7
I think the thermistors help National Semi's keep a little more stable with thermistors, but importantly allow it to bias up quickly.

With no thermistors, and IRF's or Toshibas, I see rock solid offset (no drifting). It does take longer to warm up, but I say doesn't make much difference in sound after 30 minutes.
__________________
Last 2014 Salas GB, ends Nov 30th Here to Sign Up! |F5TC Boards and power supplies available PM| Hot-Rod DCB1 boards and kits available PM |Mesmerize kits available (no boards)
  Reply With Quote
Old 29th July 2010, 05:32 PM   #513
sangram is online now sangram  India
diyAudio Member
 
Join Date: Sep 2002
Location: India
I find that there is a big variance between summer and winter bias and offset levels without thermistors. Basically, once you set the bias without thermistors, the amp likes to remain at the same ambient conditions that you had when you set the bias.

Else the bias goes up when the ambient temps increase, and down in winter or monsoon seasons. Thermistors do keep this more stable and reduce the amount of fiddling one has to do to keep everything nice and happy, but what good is an amp if you don't have to open up the hood once in a while anyway? And in my case, it's pretty much unusable with the 35 degree + room temperatures of a tropical summer, so for me it's a winter amp only.

However, omitting the thermistors results in much more stable bias and offset over a short-term period - personally speaking. I checked over a period of about ten days and the bias did not move at all from where I set it, and the offset was <2mV on each channel. Picture changes when the seasons change though, but I prefer that to a shifting bias point that is almost impossible to pin down with the default configuration. I end up having to keep the amp on for an hour or so to get bias to the exact point I want it at, which is fine as it is playing music at the time
  Reply With Quote
Old 30th July 2010, 02:30 PM   #514
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Peter, can I still order a set of your F-5 boards?

russellc
  Reply With Quote
Old 30th July 2010, 09:17 PM   #515
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Quote:
Originally Posted by Peter Daniel View Post
I did some measurements how bias stabilizes in my amps (without thermistors): F5 pcb group buy...
Peter, in post 300 you said once it reached .659 "It was steady as a rock."
Is it OK to leave at this higher than .59 bias point? Or did you scale it back down?

thanks,

Russellc
  Reply With Quote
Old 4th August 2010, 10:37 PM   #516
diyAudio Member
 
regiregi22's Avatar
 
Join Date: May 2009
Location: Madrid (Spain)
PSU and F5 boards perfectly received and packed.

Thank you very much, Peter

Regards,
Regi
__________________
diyAudio, doing it as big as you can, JUST BECAUSE WE CAN!
  Reply With Quote
Old 5th August 2010, 02:36 PM   #517
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Peter, are you on vacation, or is this buy now closed?

Russellc
  Reply With Quote
Old 6th August 2010, 07:24 AM   #518
lloop9 is offline lloop9  Singapore
diyAudio Member
 
Join Date: Jan 2004
Location: 1 degree north of the equator.
I'm interested in a set as well...
  Reply With Quote
Old 12th August 2010, 08:34 PM   #519
diyAudio Member
 
Join Date: Jul 2008
Can I still order a set of your PSU and F5 boards?
Thanks
  Reply With Quote
Old 13th August 2010, 02:36 PM   #520
diyAudio Member
 
Join Date: Mar 2003
Location: midwest
Quote:
Originally Posted by angolocottura View Post
Can I still order a set of your PSU and F5 boards?
Thanks
I think I got his last set of F-5 boards. I dont know if there are plans to have more made. Peter told me he had the PS boards still. Will there be more Peter?

Russellc
  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
F3 pcb group buy... h_a Group Buys 253 23rd December 2008 01:40 PM
new to group Lemalin22 Introductions 3 22nd June 2007 02:22 AM
What a group! EvilGenius Introductions 6 25th May 2006 06:16 PM
ono group buy xsnailx Pass Labs 106 14th March 2004 02:24 AM


New To Site? Need Help?

All times are GMT. The time now is 07:59 PM.


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