Dan d'Agostino MOMENTUM: Sonic Character like pure ClassA/SE despite low Idle Power ? - Page 14 - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 16th October 2012, 12:09 PM   #131
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by nRm View Post
I'd been thinking about your reply and may be you doubt about my 2SC6145 assertion.

Look here, at the sixth page, the first image at the right side.
Good pictures from inside on URL
http://dagostinoinc.com/documents/356_Dan_cover.pdf
Thank you for this advice.
more pics from german's magazine "AUDIO"
http://www.audio.de/bildergalerie/bi...m-1368187.html

It is only a matter of time until a clone turns up. Circuit topology must actually be easy to clone, because there are no SMD parts in use. If one drawn all transistors in parallel mode as one pcs in the reverse engineered schematic diagram, one get an "easy to bild" and good to understand circuit - so I think.

The main flaw in this device are at first glance the Panasonic electrolytic capacitors, which have no chance against this from follow URL for example:
http://www.ftcap.de/index.php/screw-...5000-h-92.html

OTOH this amp is a very low cost amp in comparison to the following models:
HigherFi-Ultimate - The Worlds Best and Most Expensive Audio Amp and Amplifiers
Thus no more expensive caps can be use (but the advice on the rear panel "no user serviceable parts inside" therefore is wrong).

BTW - who can provide a translate from this test review?

other URLs:
http://www.whatsbestforum.com/showth...ntum-Amplifier
http://www.youtube.com/watch?v=vXLaTWbS5SQ

Last edited by tiefbassuebertr; 16th October 2012 at 12:26 PM.
  Reply With Quote
Old 8th January 2013, 08:14 AM   #132
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
post 36 about
Using Many Small Signal Transistors Paralleled in place of one output Transistor
shows the output stage section - thank you for upload the image.
  Reply With Quote
Old 18th January 2013, 06:50 AM   #133
diyAudio Member
 
LineSource's Avatar
 
Join Date: Sep 2003
Location: SiliconValley
"It seems the output transistors are 2SC6145, and (highly) probably 2SA2223"

If the on-line Sanken datasheets are accurate, this NPN - PNP complementary pair are not very well matched.

Sanken 2SA2223 PNP fT=35Mhz, Cob=500pF
Sanken 2SC6145 NPN fT=60Mhz, Cob=250pF
Attached Images
File Type: jpg Momentum sankens.jpg (113.2 KB, 372 views)
  Reply With Quote
Old 18th January 2013, 09:54 AM   #134
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
2SC6145 are very nice and linear, I was considering them for my version of the JLH69.
__________________
"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938
  Reply With Quote
Old 18th January 2013, 02:12 PM   #135
Account disabled at member's request
 
Join Date: May 2006
Quote:
Originally Posted by LineSource View Post
"It seems the output transistors are 2SC6145, and (highly) probably 2SA2223"

If the on-line Sanken datasheets are accurate, this NPN - PNP complementary pair are not very well matched.

Sanken 2SA2223 PNP fT=35Mhz, Cob=500pF
Sanken 2SC6145 NPN fT=60Mhz, Cob=250pF
No Bjts are really, the same matching diversity is found from onsemi pairs and for that matter from all manufacturers. This not only applies to output transistors but also small signal transistors.
  Reply With Quote
Old 18th January 2013, 02:33 PM   #136
Telstar is offline Telstar  Italy
diyAudio Member
 
Join Date: Dec 2007
Location: Italy
Small signal transistors are MUCH easier to match, especially Toshiba ones, IME.

BJT power devices hard to match? try mosfets
Shall we all go quasi?
__________________
"The total harmonic distortion is not a measure of the degree of distastefulness to the listener and it is recommended that its use should be discontinued." D. Masa, 1938
  Reply With Quote
Old 18th January 2013, 03:05 PM   #137
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
The hFe lines of the pair don't look that bad.
__________________
The buck stops Here
  Reply With Quote
Old 8th February 2014, 07:51 PM   #138
diyAudio Member
 
tiefbassuebertr's Avatar
 
Join Date: Jul 2005
Location: D-55629 Schwarzerden
Quote:
Originally Posted by tiefbassuebertr View Post
Are there any news concerning listening tests and the topology ?
I am still looking for the schematic.
  Reply With Quote
Old 8th February 2014, 08:07 PM   #139
a.wayne is offline a.wayne  United States
Sin Bin
 
Join Date: May 2008
Location: Front Row Center
Good luck with that .....
  Reply With Quote
Old 17th September 2014, 09:19 PM   #140
diyAudio Member
 
Join Date: Jun 2006
Location: Darmstadt
I'm interessted in it too.. The only thing I could find where some inside pictures....maybe some amp topology guru knows what it could be ?

http://www.avx.hu/forum/uploads/mont...1342213263.jpg

http://highfidelity.pl/foto_testy/1303/dagostino/16.jpg

Probably nothing new for you.
  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
Dan D'Agostino removed from Krell a.wayne Everything Else 4 9th November 2011 10:50 PM
SE ClassA with low dissipation @ idle - is this it ? Bernhard Pass Labs 39 2nd December 2003 12:24 PM


New To Site? Need Help?

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