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.

Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
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 14th March 2018, 12:23 AM   #21
Michael Rothacher is offline Michael Rothacher  United States
AudioMaker.Tech
diyAudio Member
 
Michael Rothacher's Avatar
 
Join Date: May 2001
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
This reminds me of that time I defended Pons and Fleischmann.
__________________
Visit AudioMaker.Tech
  Reply With Quote
Old 14th March 2018, 12:35 AM   #22
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
logic is quite simple , me personally being used to make much more complicated and less possible ookups :

1.instead on Edcor PC600/15K , eyes fell down on Jensen 123flpch laying on bench
2.instead of taking square of 4 , there was just 4 accounted in calculus (wadamistaka) , which is completely easy to do , considering constant squek of Greedy Boyz , shoutng "More! More! More! More!)
3. so , there it is ...... xformer (plus OS) having roughly 24K (indeed close , taking in account losses ) divided with 4 (voltage transfer ratio of Jensen repeater used as autoformer) , instead of 4^2 ...... is giving 6K

which is soso easy load for anything , except sissy toob preamps (if you make it as from Yore , and majority are)



or is it more likely that NP is simply Bad Boy , expecting lavish jump in sales , as result of his malevolence

__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 14th March 2018, 06:33 AM   #23
generg is offline generg  Germany
diyAudio Member
 
generg's Avatar
 
Join Date: Jul 2009
Location: Near Frankfurt
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
1+5 or 1+ 1/5 for the autoformer
__________________
and the First Wtt is......a really First Class PSS Idea
  Reply With Quote
Old 14th March 2018, 07:17 AM   #24
chip_mk is offline chip_mk  Macedonia
diyAudio Member
 
Join Date: Jul 2005
Location: Skopje, Macedonia
Those 47k R6 & R7 are easy bootstrapable.
  Reply With Quote
Old 14th March 2018, 09:15 AM   #25
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
yes , but why
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 14th March 2018, 11:18 AM   #26
chip_mk is offline chip_mk  Macedonia
diyAudio Member
 
Join Date: Jul 2005
Location: Skopje, Macedonia
For those insisting to eliminate input follower (not wise in my opinion).
  Reply With Quote
Old 14th March 2018, 09:34 PM   #27
Nelson Pass is offline Nelson Pass  United States
The one and only
 
Nelson Pass's Avatar
 
Join Date: Mar 2001
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
It so happens that prototypes of the next DIY amplifier are on my bench
anyway, so I measured several examples.

Nothing but the facts, ma'am.

The primary load with the Edcor used 1:5 and with 23.5K secondary load
is 795 ohms.

Distortion of the transformer with 25 ohm source and 1 KHz is .02%
from about 1 watt to 25 watts (equivalent voltage, 8 ohms).

The distortion from the Toshiba Jfet buffer is less that that up to the
25 watt equivalent output.

For the Jensen JT-123-FLPCH set up as a 1:4 auto-former, and under the
same test conditions, the primary load was 1.20 Kohm. Distortion
was about .003%.

For the Cinemag CMOQ-4LPC, also a 1:4 auto-former, the load was
1.25K, and the distortion was .002%

  Reply With Quote
Old 14th March 2018, 10:10 PM   #28
Zen Mod is online now Zen Mod  Serbia
Official Court Jester
diyAudio Member
 
Zen Mod's Avatar
 
Join Date: Jan 2003
Location: ancient Batsch , behind Iron Curtain
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
Attached Images
File Type: jpg Rin.jpg (121.3 KB, 301 views)
__________________
my Papa is smarter than your Nelson !
clean thread; Cook Book;PSM LS Cook Book;Baby DiyA ;Mighty ZM's Bloggg;Papatreasure;Papa...© by Mighty ZM
  Reply With Quote
Old 14th March 2018, 10:28 PM   #29
Mark Johnson is offline Mark Johnson  United States
diyAudio Member
 
Mark Johnson's Avatar
 
Join Date: May 2011
Location: Silicon Valley
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
Thanks for the measured data! The Edcor's Zin is higher than the prediction from [23.5K / (1 + turnsratio)^2] and the other two transformer's Zin are lower than math predicts.

Quote:
Distortion of the transformer with 25 ohm source and 1 KHz is .02%
from about 1 watt to 25 watts (equivalent voltage, 8 ohms). The distortion from the Toshiba Jfet buffer is less that that up to the 25 watt equivalent output.
Folks who contemplate replacing the Toshiba JFET buffer with "something else": you now know where your minimum-acceptable-performance target lies.
  Reply With Quote
Old 15th March 2018, 09:52 PM   #30
chede is offline chede  Germany
... fascinated by amps
diyAudio Member
 
chede's Avatar
 
Join Date: Jan 2016
Location: In the Düsseldorf suburbs
Perplexed about M2 amplifier circuit impedance: schematic vs. user manual
Quote:
Originally Posted by Michael Rothacher View Post
This reminds me of that time I defended Pons and Fleischmann.
But Michael, that was nearly thirty years ago !
At that time I was still a scientist myself ...

To keep with the off-topic topic a bit longer, what do you think of Helion Energy ?

Best regards,
Claas
  Reply With Quote

Reply


Perplexed about M2 amplifier circuit impedance: schematic vs. user manualHide 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
Circuit Diagram / Schematic & Full Manual 4 Crown Ic-150 Pre Amp Wanted thermal runaway Solid State 5 1st September 2014 04:47 AM
Seek help: Leader LDM-171 user manual (Service Manual) 0451ym Parts 1 21st November 2013 03:10 PM
Crown D-60 Dual-channel Power Amplifier User Manual For Sale mv331 Swap Meet 0 21st May 2009 05:37 AM
Pioneer DV-656a or DV-655a user manual/schematic kenlow Digital Source 0 27th January 2004 08:36 AM


New To Site? Need Help?

All times are GMT. The time now is 03:26 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki