Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Pass Labs This forum is dedicated to Pass Labs discussion.

The diyAudio First Watt M2x
The diyAudio First Watt M2x
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 18th October 2020, 01:51 AM   #3691
Audiobear is offline Audiobear  United States
diyAudio Member
 
Audiobear's Avatar
 
Join Date: Jan 2005
Location: North Woods of Idaho
The diyAudio First Watt M2x
Agreed. That would indeed be an interesting test.
__________________
WHAMMY, SSII, Noir, ACA, M2X (with H9KPxG)
  Reply With Quote
Old 18th October 2020, 06:49 AM   #3692
MEPER is offline MEPER  Denmark
diyAudio Member
 
MEPER's Avatar
 
Join Date: Nov 2017
Location: Copenhagen
It could also be interesting to know how close to the "full" trace curve one of the "matched" pairs are. It should be easy to test Vgs at other current settings using the test jig? .....maybe one pair is closer than other?
But if it will not improve performance then it may be just waste of time.....other than for technical interest.
  Reply With Quote
Old 18th October 2020, 10:00 AM   #3693
thompsontechs is offline thompsontechs  United States
Freedom or Death
diyAudio Member
 
thompsontechs's Avatar
 
Join Date: Sep 2019
Location: Illinois
The diyAudio First Watt M2x
Quote:
Originally Posted by grataku View Post
My comment was general about how well matched were japanese fets vs ...others

I understood... I have some Phillips on the way, I'll jig them and post those numbers too.
__________________
Who's your Daddy? Pappa of course.
  Reply With Quote
Old 18th October 2020, 10:03 AM   #3694
thompsontechs is offline thompsontechs  United States
Freedom or Death
diyAudio Member
 
thompsontechs's Avatar
 
Join Date: Sep 2019
Location: Illinois
The diyAudio First Watt M2x
Quote:
Originally Posted by Audiobear View Post
I find it interesting that all of you really experienced DIYers are willing to scan pages of numbers to find a match. I find that very challenging. I just sorted the values in ascending order with Excel. To belabor the obvious, each adjacent pair taken stepwise is the closest match. As Mark has said, how many matched pairs you have depends on what you define as a match. I hope someone tries pairs with different matching criteria (eg 5mV,10 mV, 20 mV Etc). I'd like to know how close the matching needs to be to make an audible improvement.

Bah, a logical approach which that is more likely to be as accurate as possible.... Phooey!
__________________
Who's your Daddy? Pappa of course.
  Reply With Quote
Old 18th October 2020, 06:52 PM   #3695
grataku is offline grataku  United States
diyAudio Member
 
Join Date: Dec 2000
Location: -
Quote:
Originally Posted by Audiobear View Post
I find it interesting that all of you really experienced DIYers are willing to scan pages of numbers to find a match. I find that very challenging. I just sorted the values in ascending order with Excel. To belabor the obvious, each adjacent pair taken stepwise is the closest match. As Mark has said, how many matched pairs you have depends on what you define as a match. I hope someone tries pairs with different matching criteria (eg 5mV,10 mV, 20 mV Etc). I'd like to know how close the matching needs to be to make an audible improvement.
LOL
Unless you have a real time instrument that records all the measurements and autosaves them in an excel sheet, one still needs to type in the numbers and label all the physical parts then, after sorting, re-scan all the measured parts find the indexing that matches the sorted list...so the time savings of the excel sorting is minimal.
  Reply With Quote
Old 18th October 2020, 07:04 PM   #3696
Mark Johnson is offline Mark Johnson  United States
diyAudio Donor
diyAudio Member
 
Mark Johnson's Avatar
 
Join Date: May 2011
Location: Silicon Valley
The diyAudio First Watt M2x
In my initial write-up on August 12, I mentioned the data crunching method I used. It's identical to the one described by Audiobear.

Quote:
Originally Posted by Mark Johnson View Post
I knew I wanted to get a sorted list of measured VGS, and then look for adjacent measurements that were very very similar (or identical!). No doubt there are dozens of ways that can achieve this, some of them easier than others. I decided to use a spreadsheet, Microsoft Excel, because sorting numerical values is especially easy in a spreadsheet. Then I told Excel to subtract adjacent values, giving the delta-VGS for each pair of JFETs.
  Reply With Quote
Old Yesterday, 09:03 PM   #3697
thompsontechs is offline thompsontechs  United States
Freedom or Death
diyAudio Member
 
thompsontechs's Avatar
 
Join Date: Sep 2019
Location: Illinois
The diyAudio First Watt M2x
Quote:
Originally Posted by donhughes111 View Post
JT, That is so kind of you. Not only do I get to follow your posts around and "copy" your ideas but now this. I was thinking of doing the same thing. Seems kind of wasteful to have 50 people order 50 J113's and only use a couple.
Thoughts? I'm happy to help or happy to say yes.

Hey, and if Mark says no, I's have a hundred to give away. He has certainly done the heavy lifting on this one (and others). Kind of makes me feel obligated.

The stamps would cost more than the transistors. What does that have to say about tech.
Don
Don, I have my pairs, but shoot me PM and let me know your status and we can go from there.
__________________
Who's your Daddy? Pappa of course.
  Reply With Quote
Old Yesterday, 09:35 PM   #3698
donhughes111 is offline donhughes111
diyAudio Member
 
Join Date: Dec 2019
Will do.
  Reply to this post

Reply


The diyAudio First Watt M2xHide 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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
What make and model are the original drivers in Wilson Watt&Puppy 7 (WATT) aguiarrj Multi-Way 17 24th June 2017 10:39 PM
2.3 watt x 4 or 5 watt x2 SET amplifier using DECWARE Zkit1 and Zkit4 schematics Redwolf92 Tubes / Valves 12 29th October 2014 10:19 PM
diyaudio moderator vs diyaudio member Leolabs Everything Else 6 18th June 2006 08:19 AM


New To Site? Need Help?

All times are GMT. The time now is 01:06 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki