My F5 Lives!!!!!!! - Page 7 - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 8th April 2012, 11:11 PM   #61
fab is offline fab  Canada
diyAudio Member
 
fab's Avatar
 
Join Date: Mar 2004
Location: Canada
Quote:
Originally Posted by ottopilot View Post
Forgive me for I am a noob, but I did a double-take when I read this. If the goal is 50 ohms, how does replacing two 100 ohm in parallel with a single 50 ohm produce a different feedback result or measurably (or even perceptibly) change the sound? Does this have something to do with the differences between the physical construction of resistors of different power dissipation ratings? If so, anyone care to enlighten me as to what exactly is going on here?
The original F5 has sets of 100 ohms in parallel giving 50 ohms. Peter Daniels schematics suggestion is to use a single 100 ohms thus the close loop gain is doubled. The feedback ratio is:
open loop gain / close loop gain
Therefore, the feedback is reduced.

Also the removal of the protection circuit does not change the gain of the amp.
  Reply With Quote
Old 8th April 2012, 11:42 PM   #62
diyAudio Member
 
Join Date: Sep 2006
Location: Santa Rosa Beach, FL
Quote:
Originally Posted by dantwomey View Post
If these fans wouldn't melt I think it would be kind of interesting to mount them internally with an auto-temp switch.
If you are interested in an F5 fan configuration, check out my build:

Another F5 build--beautiful music, different drummer

My only concern is that, even with higher bias, the MOSFETS and heatsinks run too cool.....!!
  Reply With Quote
Old 9th April 2012, 02:20 AM   #63
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Quote:
Originally Posted by CanAm Man View Post
If you are interested in an F5 fan configuration, check out my build:

Another F5 build--beautiful music, different drummer

My only concern is that, even with higher bias, the MOSFETS and heatsinks run too cool.....!!
I'm hoping that by venting my top and bottom plates I'll get by. If not I'm familiar with muffin fans but would like something a little more discrete. As you might of read in one of my previous posts I hoping to measure the temp of my heatsinks to see if I'm in the safe zone.

Regards,
Dan
  Reply With Quote
Old 9th April 2012, 07:53 AM   #64
slomatt is offline slomatt  United States
diyAudio Member
 
Join Date: May 2005
Location: San Francisco, CA
Quote:
Originally Posted by dantwomey View Post
I have an engineer friend that I think has one of those fancy hand-held laser temperature measuring devices. I'm going to borrow it and get an actual reading on how hot my heatsinks get.

Regards,
Dan
I bought one of these $16 laser sighted infrared thermometers a while ago and it seems to work well for measuring amp temperatures. Plus, it is great for annoying the cats.

Amazon.com: HDE Temperature Gun Infrared Thermometer w/ Laser Sight: Home Improvement

- Matt
  Reply With Quote
Old 16th April 2012, 01:11 PM   #65
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Quote:
Originally Posted by Russellc View Post
Very nicely wired, I wish my F-5's internal wiring was that neat!

Russellc
One thing I've done that makes my stuff much neater and easier to assemble is the use of stakons and terminal strips. My picture below isn't that clear but I think you can see what I mean.

Click the image to open in full size.Click the image to open in full size.

Click the image to open in full size.



Regards,
Dan
  Reply With Quote
Old 16th April 2012, 05:14 PM   #66
diyAudio Member
 
Andersonix's Avatar
 
Join Date: Jan 2004
Location: Silicon Valley
I like the Euro style terminal blocks (as seen in the pic from ApexJr). These have the added advantages of not needing terminals on the wires, are easily divided into the required size, and are also completely immune to accidental contact by hand (and finger) once the stripped wire end is inserted and tightened down inside the barrel. (So they are quite safe for unwieldy 'prototyping' as well, and you can still probe the connection via the screw.)
Attached Images
File Type: jpg EUROTERMINALBLOCK1.jpg (72.7 KB, 123 views)
  Reply With Quote
Old 16th April 2012, 05:46 PM   #67
labjr is offline labjr  United States
diyAudio Member
 
Join Date: Apr 2003
Location: MA
Quote:
Originally Posted by Andersonix View Post
I like the Euro style terminal blocks (as seen in the pic from ApexJr). These have the added advantages of not needing terminals on the wires, are easily divided into the required size, and are also completely immune to accidental contact by hand (and finger) once the stripped wire end is inserted and tightened down inside the barrel. (So they are quite safe for unwieldy 'prototyping' as well, and you can still probe the connection via the screw.)
But they look like legos!
  Reply With Quote
Old 16th April 2012, 06:14 PM   #68
diyAudio Member
 
jacco vermeulen's Avatar
 
Join Date: Oct 2004
Location: At the sea front, Rotterdam or Curaçao
Send a message via Yahoo to jacco vermeulen
Legos, ha ?

http://www.diyaudio.com/forums/attac...t-tblocks2.jpg
__________________
The buck stops Here
  Reply With Quote
Old 16th April 2012, 06:21 PM   #69
diyAudio Member
 
Andersonix's Avatar
 
Join Date: Jan 2004
Location: Silicon Valley
I loved my Legos, and I attribute much of my early creative development to building things with the standard blocks. In fact, when sloping roof tiles, windows, etc. came along I felt those didn't belong, as they were too specific and limited the imagination. (I guess I was a fundamentalist Lego builder at 7 years old -- or just not into civil engineering -- ME's make weapons; CE's make targets...!)
Of course I made exceptions for useful pieces like hinges, rotating bearings, wheels, and ball and socket joints -- things that one could make into articulated vehicles.....
  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
Tetra lives!!!!! MrBurd Tubes / Valves 6 2nd October 2012 12:32 AM
She lives! Psychobiker Tubes / Valves 2 19th July 2008 11:49 PM
It lives! pjanda1 Chip Amps 1 21st May 2005 12:24 AM
How the other half lives harvey Everything Else 9 27th February 2003 12:55 AM
The Mini-A lives! Thomas Pass Labs 27 23rd November 2002 09:51 PM


New To Site? Need Help?

All times are GMT. The time now is 08:34 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